diff --git a/.github/workflows/lint-source.yml b/.github/workflows/lint-source.yml
index d425d449b..4d519ae59 100644
--- a/.github/workflows/lint-source.yml
+++ b/.github/workflows/lint-source.yml
@@ -29,4 +29,11 @@ jobs:
       run: pip install fortitude-lint ansi2txt
 
     - name: Lint the source code
-      run:  fortitude check --ignore=E001,S001,S101,M011,F001,S041,T001 ./src/*/* || true
+      run:  fortitude check --file-extensions=f90,fpp,fypp --ignore=E001,S001,S101,M011,F001,S041,T001,S101 ./src/** || true
+
+    - name: Ensure kind is specified
+      run:  fortitude check --file-extensions=f90,fpp,fypp --select=P001 ./src/**
+
+    - name: No double precision intrinsics
+      run: |
+        ! grep -iR 'dexp\|dlog\|dble\|dabs\|double\ precision\|real(8)\|real(4)\|dprod\|dmin\|dmax\|dfloat\|dreal\|dcos\|dsin\|dtan\|dsign\|dtanh\|dsinh\|dcosh\|\.d0\|\dd0' --exclude-dir=syscheck ./src/*
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ec6adf5ae..4bf8920ea 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -26,6 +26,7 @@ jobs:
       matrix:
         os:    ['ubuntu', 'macos']
         mpi:   ['mpi']
+        precision: ['']
         debug: ['debug', 'no-debug']
         intel: [true, false]
         exclude:
@@ -35,6 +36,7 @@ jobs:
         include:
           - os:    ubuntu
             mpi:   no-mpi
+            precision: single
             debug: no-debug
             intel: false
 
@@ -86,7 +88,7 @@ jobs:
       - name: Build
         run:  |
           if [ '${{ matrix.intel }}' == 'true' ]; then . /opt/intel/oneapi/setvars.sh; fi
-          /bin/bash mfc.sh build -j $(nproc) --${{ matrix.debug }} --${{ matrix.mpi }} 
+          /bin/bash mfc.sh build -j $(nproc) --${{ matrix.debug }} --${{ matrix.mpi }} --${{ matrix.precision }} 
 
       - name: Test
         run:  |
@@ -140,4 +142,4 @@ jobs:
         if:   always()
         with:
           name: logs-${{ strategy.job-index }}-${{ matrix.device }}
-          path: test-${{ matrix.device }}.out
+          path: test-${{ matrix.device }}.out
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 345e0c6a2..a5835bd24 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,6 +26,7 @@ option(MFC_POST_PROCESS  "Build post_process"                                OFF
 option(MFC_SYSCHECK      "Build syscheck"                                    OFF)
 option(MFC_DOCUMENTATION "Build documentation"                               OFF)
 option(MFC_ALL           "Build everything"                                  OFF)
+option(MFC_SINGLE_PRECISION "Build single precision"                         OFF)
 
 if (MFC_ALL)
     set(MFC_PRE_PROCESS   ON FORCE)
@@ -34,6 +35,12 @@ if (MFC_ALL)
     set(MFC_DOCUMENTATION ON FORCE)
 endif()
 
+if (MFC_SINGLE_PRECISION)
+    add_compile_definitions(MFC_SINGLE_PRECISION)
+else()
+    add_compile_definitions(MFC_DOUBLE_PRECISION)
+endif()
+
 
 # CMake Library Imports
 
diff --git a/README.md b/README.md
index 6f89bbb73..867dfe307 100644
--- a/README.md
+++ b/README.md
@@ -161,6 +161,7 @@ They are organized below. Just click the drop-downs!
 	* \>66K AMD GPUs on the first exascale computer, [OLCF Frontier](https://www.olcf.ornl.gov/frontier/) (AMD MI250X-based)
 * Near compute roofline behavior
 * RDMA (remote data memory access; GPU-GPU direct communication) via GPU-aware MPI on NVIDIA (CUDA-aware MPI) and AMD GPU systems
+* Optional single-precision computation and storage
 </details>
 
 <details>
diff --git a/docs/documentation/getting-started.md b/docs/documentation/getting-started.md
index 5227ec77e..3245df892 100644
--- a/docs/documentation/getting-started.md
+++ b/docs/documentation/getting-started.md
@@ -126,6 +126,7 @@ MFC can be built with support for various (compile-time) features:
 | **Debug**          | `--debug`   | `--no-debug`   | Off     | Requests the compiler build MFC in debug mode.                  |
 | **GCov**           | `--gcov`    | `--no-gcov`    | Off     | Builds MFC with coverage flags on.                              |
 | **Unified Memory** | `--unified` | `--no-unified` | Off     | Builds MFC with unified CPU/GPU memory (GH-200 superchip only)  |
+| **Single**         | `--single`  | `--no-single`  | Off     | Builds MFC in single precision     
 
 _⚠️ The `--gpu` option requires that your compiler supports OpenACC for Fortran for your target GPU architecture._
 
diff --git a/misc/m_silo_proxy.f90 b/misc/m_silo_proxy.f90
index 2f3ca4d8f..c2e57d542 100755
--- a/misc/m_silo_proxy.f90
+++ b/misc/m_silo_proxy.f90
@@ -189,9 +189,9 @@ function DBPUTQM(dbid, name, lname, xname, lxname, yname, lyname, & !! -
         integer, intent(IN) :: lyname
         character(LEN=*), intent(IN) :: zname
         integer, intent(IN) :: lzname
-        real(kind(0d0)), dimension(:), intent(IN) :: x
-        real(kind(0d0)), dimension(:), intent(IN) :: y
-        real(kind(0d0)), dimension(:), intent(IN) :: z
+        real(wp), dimension(:), intent(IN) :: x
+        real(wp), dimension(:), intent(IN) :: y
+        real(wp), dimension(:), intent(IN) :: z
         integer, dimension(:), intent(IN) :: dims
         integer, intent(IN) :: ndims
         integer, intent(IN) :: datatype
@@ -215,8 +215,8 @@ function DBPUTCURVE(dbid, curvename, lcurvename, xvals, yvals, & !! ----
         integer, intent(IN) :: dbid
         character(LEN=*), intent(IN) :: curvename
         integer, intent(IN) :: lcurvename
-        real(kind(0d0)), dimension(:), intent(IN) :: xvals
-        real(kind(0d0)), dimension(:), intent(IN) :: yvals
+        real(wp), dimension(:), intent(IN) :: xvals
+        real(wp), dimension(:), intent(IN) :: yvals
         integer, intent(IN) :: datatype
         integer, intent(IN) :: npoints
         integer, intent(IN) :: optlist_id
@@ -264,7 +264,7 @@ function DBPUTQV1(dbid, name, lname, meshname, lmeshname, var, & !! ----
         integer, intent(IN) :: lname
         character(LEN=*), intent(IN) :: meshname
         integer, intent(IN) :: lmeshname
-        real(kind(0d0)), dimension(:, :, :), intent(IN) :: var
+        real(wp), dimension(:, :, :), intent(IN) :: var
         integer, dimension(:), intent(IN) :: dims
         integer, intent(IN) :: ndims
         integer, intent(IN) :: mixvar
diff --git a/src/common/include/macros.fpp b/src/common/include/macros.fpp
index c1f447a26..cdaa48ff5 100644
--- a/src/common/include/macros.fpp
+++ b/src/common/include/macros.fpp
@@ -92,8 +92,8 @@
     end if
 #:enddef
 
-#define t_vec3   real(kind(0d0)), dimension(1:3)
-#define t_mat4x4 real(kind(0d0)), dimension(1:4,1:4)
+#define t_vec3   real(wp), dimension(1:3)
+#define t_mat4x4 real(wp), dimension(1:4,1:4)
 
 #:def ASSERT(predicate, message = None)
     if (.not. (${predicate}$)) then
diff --git a/src/common/m_checker_common.fpp b/src/common/m_checker_common.fpp
index 3623fabba..e10bc90af 100644
--- a/src/common/m_checker_common.fpp
+++ b/src/common/m_checker_common.fpp
@@ -18,7 +18,7 @@ module m_checker_common
 
     implicit none
 
-    private; public :: s_check_inputs_common
+    private; public :: s_check_inputs_common, wp
 
 contains
 
@@ -61,7 +61,7 @@ contains
         !! Called by s_check_inputs_common for simulation and post-processing
     subroutine s_check_inputs_time_stepping
         if (cfl_dt) then
-            @:PROHIBIT(cfl_target < 0 .or. cfl_target > 1d0)
+            @:PROHIBIT(cfl_target < 0 .or. cfl_target > 1._wp)
             @:PROHIBIT(t_stop <= 0)
             @:PROHIBIT(t_save <= 0)
             @:PROHIBIT(t_save > t_stop)
@@ -144,10 +144,10 @@ contains
         @:PROHIBIT(relax .and. model_eqns /= 3, "phase change requires model_eqns = 3")
         @:PROHIBIT(relax .and. relax_model < 0, "relax_model must be in between 0 and 6")
         @:PROHIBIT(relax .and. relax_model > 6, "relax_model must be in between 0 and 6")
-        @:PROHIBIT(relax .and. palpha_eps <= 0d0, "palpha_eps must be positive")
-        @:PROHIBIT(relax .and. palpha_eps >= 1d0, "palpha_eps must be less than 1")
-        @:PROHIBIT(relax .and. ptgalpha_eps <= 0d0, "ptgalpha_eps must be positive")
-        @:PROHIBIT(relax .and. ptgalpha_eps >= 1d0, "ptgalpha_eps must be less than 1")
+        @:PROHIBIT(relax .and. palpha_eps <= 0._wp, "palpha_eps must be positive")
+        @:PROHIBIT(relax .and. palpha_eps >= 1._wp, "palpha_eps must be less than 1")
+        @:PROHIBIT(relax .and. ptgalpha_eps <= 0._wp, "ptgalpha_eps must be positive")
+        @:PROHIBIT(relax .and. ptgalpha_eps >= 1._wp, "ptgalpha_eps must be less than 1")
         @:PROHIBIT((.not. relax) .and. &
             ((relax_model /= dflt_int) .or. (.not. f_is_default(palpha_eps)) .or. (.not. f_is_default(ptgalpha_eps))), &
             "relax is not set as true, but other phase change parameters have been modified. " // &
@@ -262,27 +262,27 @@ contains
 
         do i = 1, num_fluids
             call s_int_to_str(i, iStr)
-            @:PROHIBIT(.not. f_is_default(fluid_pp(i)%gamma) .and. fluid_pp(i)%gamma <= 0d0, &
+            @:PROHIBIT(.not. f_is_default(fluid_pp(i)%gamma) .and. fluid_pp(i)%gamma <= 0._wp, &
                 "fluid_pp("//trim(iStr)//")%gamma must be positive")
 
             @:PROHIBIT(model_eqns == 1 .and. (.not. f_is_default(fluid_pp(i)%gamma)), &
                 "model_eqns = 1 does not support fluid_pp("//trim(iStr)//")%gamma")
 
-            @:PROHIBIT((i <= num_fluids + bub_fac .and. fluid_pp(i)%gamma <= 0d0) .or. &
+            @:PROHIBIT((i <= num_fluids + bub_fac .and. fluid_pp(i)%gamma <= 0._wp) .or. &
                 (i > num_fluids + bub_fac .and. (.not. f_is_default(fluid_pp(i)%gamma))), &
                 "for fluid_pp("//trim(iStr)//")%gamma")
 
-            @:PROHIBIT(.not. f_is_default(fluid_pp(i)%pi_inf) .and. fluid_pp(i)%pi_inf < 0d0, &
+            @:PROHIBIT(.not. f_is_default(fluid_pp(i)%pi_inf) .and. fluid_pp(i)%pi_inf < 0._wp, &
                 "fluid_pp("//trim(iStr)//")%pi_inf must be non-negative")
 
             @:PROHIBIT(model_eqns == 1 .and. (.not. f_is_default(fluid_pp(i)%pi_inf)), &
                 "model_eqns = 1 does not support fluid_pp("//trim(iStr)//")%pi_inf")
 
-            @:PROHIBIT((i <= num_fluids + bub_fac .and. fluid_pp(i)%pi_inf < 0d0) .or. &
+            @:PROHIBIT((i <= num_fluids + bub_fac .and. fluid_pp(i)%pi_inf < 0._wp) .or. &
                 (i > num_fluids + bub_fac .and. (.not. f_is_default(fluid_pp(i)%pi_inf))), &
                 "for fluid_pp("//trim(iStr)//")%pi_inf")
 
-            @:PROHIBIT(fluid_pp(i)%cv < 0d0, &
+            @:PROHIBIT(fluid_pp(i)%cv < 0._wp, &
                 "fluid_pp("//trim(iStr)//")%cv must be positive")
         end do
     end subroutine s_check_inputs_stiffened_eos
@@ -293,7 +293,7 @@ contains
 
         integer :: i
 
-        @:PROHIBIT(surface_tension .and. sigma < 0d0, &
+        @:PROHIBIT(surface_tension .and. sigma < 0._wp, &
             "sigma must be greater than or equal to zero")
 
         @:PROHIBIT(surface_tension .and. sigma == dflt_real, &
@@ -321,9 +321,9 @@ contains
         !! Called by s_check_inputs_common for all three stages
     subroutine s_check_inputs_moving_bc
         #:for X, VB2, VB3 in [('x', 'vb2', 'vb3'), ('y', 'vb3', 'vb1'), ('z', 'vb1', 'vb2')]
-            if (any((/bc_${X}$%vb1, bc_${X}$%vb2, bc_${X}$%vb3/) /= 0d0)) then
+            if (any((/bc_${X}$%vb1, bc_${X}$%vb2, bc_${X}$%vb3/) /= 0._wp)) then
                 if (bc_${X}$%beg == -15) then
-                    if (any((/bc_${X}$%${VB2}$, bc_${X}$%${VB3}$/) /= 0d0)) then
+                    if (any((/bc_${X}$%${VB2}$, bc_${X}$%${VB3}$/) /= 0._wp)) then
                         call s_mpi_abort("bc_${X}$%beg must be -15 if "// &
                                          "bc_${X}$%${VB2}$ or bc_${X}$%${VB3}$ "// &
                                          "is set. Exiting ...")
@@ -336,9 +336,9 @@ contains
         #:endfor
 
         #:for X, VE2, VE3 in [('x', 've2', 've3'), ('y', 've3', 've1'), ('z', 've1', 've2')]
-            if (any((/bc_${X}$%ve1, bc_${X}$%ve2, bc_${X}$%ve3/) /= 0d0)) then
+            if (any((/bc_${X}$%ve1, bc_${X}$%ve2, bc_${X}$%ve3/) /= 0._wp)) then
                 if (bc_${X}$%end == -15) then
-                    if (any((/bc_${X}$%${VE2}$, bc_${X}$%${VE3}$/) /= 0d0)) then
+                    if (any((/bc_${X}$%${VE2}$, bc_${X}$%${VE3}$/) /= 0._wp)) then
                         call s_mpi_abort("bc_${X}$%end must be -15 if "// &
                                          "bc_${X}$%${VE2}$ or bc_${X}$%${VE3}$ "// &
                                          "is set. Exiting ...")
diff --git a/src/common/m_constants.fpp b/src/common/m_constants.fpp
index 74b144588..2705df922 100644
--- a/src/common/m_constants.fpp
+++ b/src/common/m_constants.fpp
@@ -4,13 +4,15 @@
 
 module m_constants
 
+    use m_precision_select
+
     character, parameter :: dflt_char = ' ' !< Default string value
 
-    real(kind(0d0)), parameter :: dflt_real = -1d6                !< Default real value
-    real(kind(0d0)), parameter :: sgm_eps = 1d-16               !< Segmentation tolerance
-    real(kind(0d0)), parameter :: small_alf = 1d-11                !< Small alf tolerance
-    real(kind(0d0)), parameter :: pi = 3.141592653589793d0 !< Pi
-    real(kind(0d0)), parameter :: verysmall = 1.d-12              !< Very small number
+    real(wp), parameter :: dflt_real = -1e6_wp                !< Default real value
+    real(wp), parameter :: sgm_eps = 1e-16_wp               !< Segmentation tolerance
+    real(wp), parameter :: small_alf = 1e-11_wp                !< Small alf tolerance
+    real(wp), parameter :: pi = 3.141592653589793_wp !< Pi
+    real(wp), parameter :: verysmall = 1.e-12_wp              !< Very small number
 
     integer, parameter :: num_stcls_min = 5    !< Minimum # of stencils
     integer, parameter :: path_len = 400  !< Maximum path length
@@ -22,21 +24,21 @@ module m_constants
     integer, parameter :: num_patches_max = 10
     integer, parameter :: pathlen_max = 400
     integer, parameter :: nnode = 4    !< Number of QBMM nodes
-    real(kind(0d0)), parameter :: capillary_cutoff = 1e-6 !< color function gradient magnitude at which to apply the surface tension fluxes
-    real(kind(0d0)), parameter :: acoustic_spatial_support_width = 2.5d0 !< Spatial support width of acoustic source, used in s_source_spatial
-    real(kind(0d0)), parameter :: dflt_vcfl_dt = 100d0 !< value of vcfl_dt when viscosity is off for computing adaptive timestep size
-    real(kind(0d0)), parameter :: broadband_spectral_level_constant = 20d0 !< The constant to scale the spectral level at the lower frequency bound
-    real(kind(0d0)), parameter :: broadband_spectral_level_growth_rate = 10d0 !< The spectral level constant to correct the magnitude at each frqeuency to ensure the source is overall broadband
+    real(wp), parameter :: capillary_cutoff = 1e-6 !< color function gradient magnitude at which to apply the surface tension fluxes
+    real(wp), parameter :: acoustic_spatial_support_width = 2.5_wp !< Spatial support width of acoustic source, used in s_source_spatial
+    real(wp), parameter :: dflt_vcfl_dt = 100._wp !< value of vcfl_dt when viscosity is off for computing adaptive timestep size
+    real(wp), parameter :: broadband_spectral_level_constant = 20._wp !< The constant to scale the spectral level at the lower frequency bound
+    real(wp), parameter :: broadband_spectral_level_growth_rate = 10._wp !< The spectral level constant to correct the magnitude at each frqeuency to ensure the source is overall broadband
 
     ! IBM+STL interpolation constants
     integer, parameter :: Ifactor_2D = 50 !< Multiple factor of the ratio (edge to cell width) for interpolation along edges for 2D models
     integer, parameter :: Ifactor_3D = 5 !< Multiple factor of the ratio (edge to cell width) for interpolation along edges for 3D models
     integer, parameter :: Ifactor_bary_3D = 20 !< Multiple factor of the ratio (triangle area to cell face area) for interpolation on triangle facets for 3D models
     integer, parameter :: num_ray = 20 !< Default number of rays traced per cell
-    real(kind(0d0)), parameter :: ray_tracing_threshold = 0.9d0 !< Threshold above which the cell is marked as the model patch
-    real(kind(0d0)), parameter :: threshold_vector_zero = 1d-10 !< Threshold to treat the component of a vector to be zero
-    real(kind(0d0)), parameter :: threshold_edge_zero = 1d-10 !< Threshold to treat two edges to be overlapped
-    real(kind(0d0)), parameter :: threshold_bary = 1d-1 !< Threshold to interpolate a barycentric facet
-    real(kind(0d0)), parameter :: initial_distance_buffer = 1d12 !< Initialized levelset distance for the shortest path pair algorithm
+    real(wp), parameter :: ray_tracing_threshold = 0.9_wp !< Threshold above which the cell is marked as the model patch
+    real(wp), parameter :: threshold_vector_zero = 1e-10 !< Threshold to treat the component of a vector to be zero
+    real(wp), parameter :: threshold_edge_zero = 1e-10 !< Threshold to treat two edges to be overlapped
+    real(wp), parameter :: threshold_bary = 1e-1 !< Threshold to interpolate a barycentric facet
+    real(wp), parameter :: initial_distance_buffer = 1e12_wp !< Initialized levelset distance for the shortest path pair algorithm
 
 end module m_constants
diff --git a/src/common/m_delay_file_access.f90 b/src/common/m_delay_file_access.f90
index 54dd3edba..df8b368dc 100644
--- a/src/common/m_delay_file_access.f90
+++ b/src/common/m_delay_file_access.f90
@@ -1,4 +1,5 @@
 module m_delay_file_access
+    use m_precision_select
     implicit none
     private
 
@@ -14,7 +15,7 @@ subroutine DelayFileAccess(ProcessRank)
         integer, intent(in) :: ProcessRank
 
         integer :: iDelay, nFileAccessDelayIterations
-        real(kind(0d0)) :: Number, Dummy
+        real(wp) :: Number, Dummy
 
         nFileAccessDelayIterations &
             = (ProcessRank/N_PROCESSES_FILE_ACCESS)*FILE_ACCESS_DELAY_UNIT
diff --git a/src/common/m_derived_types.fpp b/src/common/m_derived_types.fpp
index 879a73c7f..7a021bdaa 100644
--- a/src/common/m_derived_types.fpp
+++ b/src/common/m_derived_types.fpp
@@ -10,23 +10,24 @@ module m_derived_types
 
     use m_constants  !< Constants
 
+    use m_precision_select
     use m_thermochem, only: num_species
 
     implicit none
 
     !> Derived type adding the field position (fp) as an attribute
     type field_position
-        real(kind(0d0)), allocatable, dimension(:, :, :) :: fp !< Field position
+        real(wp), allocatable, dimension(:, :, :) :: fp !< Field position
     end type field_position
 
     !> Derived type annexing a scalar field (SF)
     type scalar_field
-        real(kind(0d0)), pointer, dimension(:, :, :) :: sf => null()
+        real(wp), pointer, dimension(:, :, :) :: sf => null()
     end type scalar_field
 
     !> Derived type for bubble variables pb and mv at quadrature nodes (qbmm)
     type pres_field
-        real(kind(0d0)), pointer, dimension(:, :, :, :, :) :: sf => null()
+        real(wp), pointer, dimension(:, :, :, :, :) :: sf => null()
     end type pres_field
 
     !> Derived type annexing an integer scalar field (SF)
@@ -36,12 +37,12 @@ module m_derived_types
 
     !> Derived type for levelset
     type levelset_field
-        real(kind(0d0)), pointer, dimension(:, :, :, :) :: sf => null()
+        real(wp), pointer, dimension(:, :, :, :) :: sf => null()
     end type levelset_field
 
     !> Derived type for levelset norm
     type levelset_norm_field
-        real(kind(0d0)), pointer, dimension(:, :, :, :, :) :: sf => null()
+        real(wp), pointer, dimension(:, :, :, :, :) :: sf => null()
     end type levelset_norm_field
 
     type mpi_io_var
@@ -73,22 +74,24 @@ module m_derived_types
     type int_bounds_info
         integer :: beg
         integer :: end
-        real(kind(0d0)) :: vb1
-        real(kind(0d0)) :: vb2
-        real(kind(0d0)) :: vb3
-        real(kind(0d0)) :: ve1
-        real(kind(0d0)) :: ve2
-        real(kind(0d0)) :: ve3
-        real(kind(0d0)) :: pres_in, pres_out
-        real(kind(0d0)), dimension(3) :: vel_in, vel_out
-        real(kind(0d0)), dimension(num_fluids_max) :: alpha_rho_in, alpha_in
+
+        real(wp) :: vb1
+        real(wp) :: vb2
+        real(wp) :: vb3
+        real(wp) :: ve1
+        real(wp) :: ve2
+        real(wp) :: ve3
+        real(wp) :: pres_in, pres_out
+        real(wp), dimension(3) :: vel_in, vel_out
+        real(wp), dimension(num_fluids_max) :: alpha_rho_in, alpha_in
         logical :: grcbc_in, grcbc_out, grcbc_vel_out
+
     end type int_bounds_info
 
     !> Derived type adding beginning (beg) and end bounds info as attributes
     type bounds_info
-        real(kind(0d0)) :: beg
-        real(kind(0d0)) :: end
+        real(wp) :: beg
+        real(wp) :: end
     end type bounds_info
 
     !> bounds for the bubble dynamic variables
@@ -121,12 +124,12 @@ module m_derived_types
         integer :: spc !<
         !! Number of samples per cell to use when discretizing the STL object.
 
-        real(kind(0d0)) :: threshold !<
+        real(wp) :: threshold !<
         !! Threshold to turn on smoothen STL patch.
     end type ic_model_parameters
 
     type :: t_triangle
-        real(kind(0d0)), dimension(1:3, 1:3) :: v ! Vertices of the triangle
+        real(wp), dimension(1:3, 1:3) :: v ! Vertices of the triangle
         t_vec3 :: n ! Normal vector
     end type t_triangle
 
@@ -153,22 +156,22 @@ module m_derived_types
 
         integer :: geometry !< Type of geometry for the patch
 
-        real(kind(0d0)) :: x_centroid, y_centroid, z_centroid !<
+        real(wp) :: x_centroid, y_centroid, z_centroid !<
         !! Location of the geometric center, i.e. the centroid, of the patch. It
         !! is specified through its x-, y- and z-coordinates, respectively.
 
-        real(kind(0d0)) :: length_x, length_y, length_z !< Dimensions of the patch. x,y,z Lengths.
-        real(kind(0d0)) :: radius !< Dimensions of the patch. radius.
+        real(wp) :: length_x, length_y, length_z !< Dimensions of the patch. x,y,z Lengths.
+        real(wp) :: radius !< Dimensions of the patch. radius.
 
-        real(kind(0d0)), dimension(3) :: radii !<
+        real(wp), dimension(3) :: radii !<
         !! Vector indicating the various radii for the elliptical and ellipsoidal
         !! patch geometries. It is specified through its x-, y-, and z-components
         !! respectively.
 
-        real(kind(0d0)) :: epsilon, beta !<
+        real(wp) :: epsilon, beta !<
         !! The spherical harmonics eccentricity parameters.
 
-        real(kind(0d0)), dimension(3) :: normal !<
+        real(wp), dimension(3) :: normal !<
         !! Normal vector indicating the orientation of the patch. It is specified
         !! through its x-, y- and z-components, respectively.
         logical, dimension(0:num_patches_max - 1) :: alter_patch !<
@@ -184,39 +187,39 @@ module m_derived_types
         integer :: smooth_patch_id !<
         !! Identity (id) of the patch with which current patch is to get smoothed
 
-        real(kind(0d0)) :: smooth_coeff !<
-        !! Smoothing coefficient (coeff) adminstrating the size of the stencil of
+        real(wp) :: smooth_coeff !<
+        !! Smoothing coefficient (coeff) for the size of the stencil of
         !! cells across which boundaries of the current patch will be smeared out
 
-        real(kind(0d0)), dimension(num_fluids_max) :: alpha_rho
-        real(kind(0d0)) :: rho
-        real(kind(0d0)), dimension(3) :: vel
-        real(kind(0d0)) :: pres
-        real(kind(0d0)), dimension(num_fluids_max) :: alpha
-        real(kind(0d0)) :: gamma
-        real(kind(0d0)) :: pi_inf !<
-        real(kind(0d0)) :: cv !<
-        real(kind(0d0)) :: qv !<
-        real(kind(0d0)) :: qvp !<
+        real(wp), dimension(num_fluids_max) :: alpha_rho
+        real(wp) :: rho
+        real(wp), dimension(3) :: vel
+        real(wp) :: pres
+        real(wp), dimension(num_fluids_max) :: alpha
+        real(wp) :: gamma
+        real(wp) :: pi_inf !<
+        real(wp) :: cv !<
+        real(wp) :: qv !<
+        real(wp) :: qvp !<
 
         !! Primitive variables associated with the patch. In order, these include
         !! the partial densities, density, velocity, pressure, volume fractions,
         !! specific heat ratio function and the liquid stiffness function.
 
-        real(kind(0d0)), dimension(6) :: tau_e
+        real(wp), dimension(6) :: tau_e
         !! Elastic stresses added to primitive variables if hypoelasticity = True
 
-        real(kind(0d0)) :: R0 !< Bubble size
-        real(kind(0d0)) :: V0 !< Bubble velocity
+        real(wp) :: R0 !< Bubble size
+        real(wp) :: V0 !< Bubble velocity
 
-        real(kind(0d0)) :: p0 !< Bubble size
-        real(kind(0d0)) :: m0 !< Bubble velocity
+        real(wp) :: p0 !< Bubble size
+        real(wp) :: m0 !< Bubble velocity
 
         integer :: hcid
         !! id for hard coded initial condition
 
-        real(kind(0d0)) :: cf_val !! color function value
-        real(kind(0d0)) :: Y(1:num_species)
+        real(wp) :: cf_val !! color function value
+        real(wp) :: Y(1:num_species)
 
         !! STL or OBJ model input parameter
         character(LEN=pathlen_max) :: model_filepath !<
@@ -235,7 +238,7 @@ module m_derived_types
         integer :: model_spc !<
         !! Number of samples per cell to use when discretizing the STL object.
 
-        real(kind(0d0)) :: model_threshold !<
+        real(wp) :: model_threshold !<
         !! Threshold to turn on smoothen STL patch.
 
     end type ic_patch_parameters
@@ -244,15 +247,15 @@ module m_derived_types
 
         integer :: geometry !< Type of geometry for the patch
 
-        real(kind(0d0)) :: x_centroid, y_centroid, z_centroid !<
+        real(wp) :: x_centroid, y_centroid, z_centroid !<
         !! Location of the geometric center, i.e. the centroid, of the patch. It
         !! is specified through its x-, y- and z-coordinates, respectively.
 
-        real(kind(0d0)) :: c, p, t, m
+        real(wp) :: c, p, t, m
 
-        real(kind(0d0)) :: length_x, length_y, length_z !< Dimensions of the patch. x,y,z Lengths.
-        real(kind(0d0)) :: radius !< Dimensions of the patch. radius.
-        real(kind(0d0)) :: theta
+        real(wp) :: length_x, length_y, length_z !< Dimensions of the patch. x,y,z Lengths.
+        real(wp) :: radius !< Dimensions of the patch. radius.
+        real(wp) :: theta
 
         logical :: slip
 
@@ -273,34 +276,34 @@ module m_derived_types
         integer :: model_spc !<
         !! Number of samples per cell to use when discretizing the STL object.
 
-        real(kind(0d0)) :: model_threshold !<
+        real(wp) :: model_threshold !<
         !! Threshold to turn on smoothen STL patch.
     end type ib_patch_parameters
 
     !> Derived type annexing the physical parameters (PP) of the fluids. These
     !! include the specific heat ratio function and liquid stiffness function.
     type physical_parameters
-        real(kind(0d0)) :: gamma   !< Sp. heat ratio
-        real(kind(0d0)) :: pi_inf  !< Liquid stiffness
-        real(kind(0d0)), dimension(2) :: Re      !< Reynolds number
-        real(kind(0d0)) :: cv      !< heat capacity
-        real(kind(0d0)) :: qv      !< reference energy per unit mass for SGEOS, q (see Le Metayer (2004))
-        real(kind(0d0)) :: qvp     !< reference entropy per unit mass for SGEOS, q' (see Le Metayer (2004))
-        real(kind(0d0)) :: mul0    !< Bubble viscosity
-        real(kind(0d0)) :: ss      !< Bubble surface tension
-        real(kind(0d0)) :: pv      !< Bubble vapour pressure
-        real(kind(0d0)) :: gamma_v !< Bubble constants (see Preston (2007), Ando (2010))
-        real(kind(0d0)) :: M_v     !< Bubble constants (see Preston (2007), Ando (2010))
-        real(kind(0d0)) :: mu_v    !< Bubble constants (see Preston (2007), Ando (2010))
-        real(kind(0d0)) :: k_v     !< Bubble constants (see Preston (2007), Ando (2010))
-        real(kind(0d0)) :: G
+        real(wp) :: gamma   !< Sp. heat ratio
+        real(wp) :: pi_inf  !< Liquid stiffness
+        real(wp), dimension(2) :: Re      !< Reynolds number
+        real(wp) :: cv      !< heat capacity
+        real(wp) :: qv      !< reference energy per unit mass for SGEOS, q (see Le Metayer (2004))
+        real(wp) :: qvp     !< reference entropy per unit mass for SGEOS, q' (see Le Metayer (2004))
+        real(wp) :: mul0    !< Bubble viscosity
+        real(wp) :: ss      !< Bubble surface tension
+        real(wp) :: pv      !< Bubble vapour pressure
+        real(wp) :: gamma_v !< Bubble constants (see Preston (2007), Ando (2010))
+        real(wp) :: M_v     !< Bubble constants (see Preston (2007), Ando (2010))
+        real(wp) :: mu_v    !< Bubble constants (see Preston (2007), Ando (2010))
+        real(wp) :: k_v     !< Bubble constants (see Preston (2007), Ando (2010))
+        real(wp) :: G
     end type physical_parameters
 
     !> Derived type annexing the flow probe location
     type probe_parameters
-        real(kind(0d0)) :: x !< First coordinate location
-        real(kind(0d0)) :: y !< Second coordinate location
-        real(kind(0d0)) :: z !< Third coordinate location
+        real(wp) :: x !< First coordinate location
+        real(wp) :: y !< Second coordinate location
+        real(wp) :: z !< Third coordinate location
     end type probe_parameters
 
     type mpi_io_airfoil_ib_var
@@ -310,12 +313,12 @@ module m_derived_types
 
     !> Derived type annexing integral regions
     type integral_parameters
-        real(kind(0d0)) :: xmin !< Min. boundary first coordinate direction
-        real(kind(0d0)) :: xmax !< Max. boundary first coordinate direction
-        real(kind(0d0)) :: ymin !< Min. boundary second coordinate direction
-        real(kind(0d0)) :: ymax !< Max. boundary second coordinate direction
-        real(kind(0d0)) :: zmin !< Min. boundary third coordinate direction
-        real(kind(0d0)) :: zmax !< Max. boundary third coordinate direction
+        real(wp) :: xmin !< Min. boundary first coordinate direction
+        real(wp) :: xmax !< Max. boundary first coordinate direction
+        real(wp) :: ymin !< Min. boundary second coordinate direction
+        real(wp) :: ymax !< Max. boundary second coordinate direction
+        real(wp) :: zmin !< Min. boundary third coordinate direction
+        real(wp) :: zmax !< Max. boundary third coordinate direction
     end type integral_parameters
 
     !> Acoustic source parameters
@@ -323,24 +326,24 @@ module m_derived_types
         integer :: pulse !< Type of pulse
         integer :: support !< Type of support
         logical :: dipole !< Whether the source is a dipole or monopole
-        real(kind(0d0)), dimension(3) :: loc !< Physical location of acoustic source
-        real(kind(0d0)) :: mag !< Acoustic pulse magnitude
-        real(kind(0d0)) :: length !< Length of planar source (2D/3D)
-        real(kind(0d0)) :: height !< Height of planar source (3D)
-        real(kind(0d0)) :: wavelength !< Wave length of pulse
-        real(kind(0d0)) :: frequency !< Frequency of pulse
-        real(kind(0d0)) :: gauss_sigma_dist !< sigma of Gaussian pulse multiplied by speed of sound
-        real(kind(0d0)) :: gauss_sigma_time !< sigma of Gaussian pulse
-        real(kind(0d0)) :: npulse !< Number of cycles of pulse
-        real(kind(0d0)) :: dir !< Direction of pulse
-        real(kind(0d0)) :: delay !< Time-delay of pulse start
-        real(kind(0d0)) :: foc_length ! < Focal length of transducer
-        real(kind(0d0)) :: aperture ! < Aperture diameter of transducer
-        real(kind(0d0)) :: element_spacing_angle !< Spacing between aperture elements in 2D acoustic array
-        real(kind(0d0)) :: element_polygon_ratio !< Ratio of aperture element diameter to side length of polygon connecting their centers, in 3D acoustic array
-        real(kind(0d0)) :: rotate_angle !< Angle of rotation of the entire circular 3D acoustic array
-        real(kind(0d0)) :: bb_bandwidth !< Bandwidth of each frequency in broadband wave
-        real(kind(0d0)) :: bb_lowest_freq !< The lower frequency bound of broadband wave
+        real(wp), dimension(3) :: loc !< Physical location of acoustic source
+        real(wp) :: mag !< Acoustic pulse magnitude
+        real(wp) :: length !< Length of planar source (2D/3D)
+        real(wp) :: height !< Height of planar source (3D)
+        real(wp) :: wavelength !< Wave length of pulse
+        real(wp) :: frequency !< Frequency of pulse
+        real(wp) :: gauss_sigma_dist !< sigma of Gaussian pulse multiplied by speed of sound
+        real(wp) :: gauss_sigma_time !< sigma of Gaussian pulse
+        real(wp) :: npulse !< Number of cycles of pulse
+        real(wp) :: dir !< Direction of pulse
+        real(wp) :: delay !< Time-delay of pulse start
+        real(wp) :: foc_length ! < Focal length of transducer
+        real(wp) :: aperture ! < Aperture diameter of transducer
+        real(wp) :: element_spacing_angle !< Spacing between aperture elements in 2D acoustic array
+        real(wp) :: element_polygon_ratio !< Ratio of aperture element diameter to side length of polygon connecting their centers, in 3D acoustic array
+        real(wp) :: rotate_angle !< Angle of rotation of the entire circular 3D acoustic array
+        real(wp) :: bb_bandwidth !< Bandwidth of each frequency in broadband wave
+        real(wp) :: bb_lowest_freq !< The lower frequency bound of broadband wave
         integer :: num_elements !< Number of elements in the acoustic array
         integer :: element_on !< Element in the acoustic array to turn on
         integer :: bb_num_freq !< Number of frequencies in the broadband wave
@@ -349,18 +352,18 @@ module m_derived_types
     !> Acoustic source source_spatial pre-calculated values
     type source_spatial_type
         integer, dimension(:, :), allocatable :: coord !< List of grid points indices with non-zero source_spatial values
-        real(kind(0d0)), dimension(:), allocatable :: val !< List of non-zero source_spatial values
-        real(kind(0d0)), dimension(:), allocatable :: angle !< List of angles with x-axis for mom source term vector
-        real(kind(0d0)), dimension(:, :), allocatable :: xyz_to_r_ratios !< List of [xyz]/r for mom source term vector
+        real(wp), dimension(:), allocatable :: val !< List of non-zero source_spatial values
+        real(wp), dimension(:), allocatable :: angle !< List of angles with x-axis for mom source term vector
+        real(wp), dimension(:, :), allocatable :: xyz_to_r_ratios !< List of [xyz]/r for mom source term vector
     end type source_spatial_type
 
     !> Ghost Point for Immersed Boundaries
     type ghost_point
 
-        real(kind(0d0)), dimension(3) :: loc !< Physical location of the ghost point
-        real(kind(0d0)), dimension(3) :: ip_loc !< Physical location of the image point
+        real(wp), dimension(3) :: loc !< Physical location of the ghost point
+        real(wp), dimension(3) :: ip_loc !< Physical location of the image point
         integer, dimension(3) :: ip_grid !< Top left grid point of IP
-        real(kind(0d0)), dimension(2, 2, 2) :: interp_coeffs !< Interpolation Coefficients of image point
+        real(wp), dimension(2, 2, 2) :: interp_coeffs !< Interpolation Coefficients of image point
         integer :: ib_patch_id !< ID of the IB Patch the ghost point is part of
         logical :: slip
         integer, dimension(3) :: DB
diff --git a/src/common/m_eigen_solver.f90 b/src/common/m_eigen_solver.f90
index 8356f78fc..0f72155e0 100644
--- a/src/common/m_eigen_solver.f90
+++ b/src/common/m_eigen_solver.f90
@@ -8,6 +8,8 @@
 !!              modifications for compatibility.
 module m_eigen_solver
 
+    use m_precision_select
+
     implicit none
 
     private; 
@@ -33,10 +35,10 @@ module m_eigen_solver
         !! @param ierr an error completion code
     subroutine cg(nm, nl, ar, ai, wr, wi, zr, zi, fv1, fv2, fv3, ierr)
         integer, intent(in) :: nm, nl
-        real(kind(0d0)), dimension(nm, nl), intent(inout) :: ar, ai
-        real(kind(0d0)), dimension(nl), intent(out) :: wr, wi
-        real(kind(0d0)), dimension(nm, nl), intent(out) :: zr, zi
-        real(kind(0d0)), dimension(nl), intent(out) :: fv1, fv2, fv3
+        real(wp), dimension(nm, nl), intent(inout) :: ar, ai
+        real(wp), dimension(nl), intent(out) :: wr, wi
+        real(wp), dimension(nm, nl), intent(out) :: zr, zi
+        real(wp), dimension(nl), intent(out) :: fv1, fv2, fv3
         integer, intent(out) :: ierr
 
         integer :: is1, is2
@@ -76,15 +78,15 @@ end subroutine cg
         !!              factors used.
     subroutine cbal(nm, nl, ar, ai, low, igh, scale)
         integer, intent(in) :: nm, nl
-        real(kind(0d0)), dimension(nm, nl), intent(inout) :: ar, ai
+        real(wp), dimension(nm, nl), intent(inout) :: ar, ai
         integer, intent(out) :: low, igh
-        real(kind(0d0)), dimension(nl), intent(out) :: scale
+        real(wp), dimension(nl), intent(out) :: scale
 
         integer :: i, j, k, l, ml, jj, iexc
-        real(kind(0d0)) :: c, f, g, r, s, b2, radix
+        real(wp) :: c, f, g, r, s, b2, radix
         logical :: noconv
 
-        radix = 16.0d0
+        radix = 16.0_wp
 
         b2 = radix*radix
         k = 1
@@ -124,7 +126,7 @@ subroutine cbal(nm, nl, ar, ai, low, igh, scale)
 
             do 110 i = 1, l
                 if (i == j) go to 110
-                if (ar(j, i) /= 0.0d0 .or. ai(j, i) /= 0.0d0) go to 120
+                if (ar(j, i) /= 0.0_wp .or. ai(j, i) /= 0.0_wp) go to 120
 110         end do
 
             ml = l
@@ -141,7 +143,7 @@ subroutine cbal(nm, nl, ar, ai, low, igh, scale)
 
             do 150 i = k, l
                 if (i == j) go to 150
-                if (ar(i, j) /= 0.0d0 .or. ai(i, j) /= 0.0d0) go to 170
+                if (ar(i, j) /= 0.0_wp .or. ai(i, j) /= 0.0_wp) go to 170
 150         end do
 
             ml = k
@@ -150,24 +152,24 @@ subroutine cbal(nm, nl, ar, ai, low, igh, scale)
 170     end do
 !     .......... now balance the submatrix in rows k to l ..........
         do 180 i = k, l
-            scale(i) = 1.0d0
+            scale(i) = 1.0_wp
 180     end do
 !     .......... iterative loop for norm reduction ..........
 190     noconv = .false.
 
         do 270 i = k, l
-            c = 0.0d0
-            r = 0.0d0
+            c = 0.0_wp
+            r = 0.0_wp
 
             do 200 j = k, l
                 if (j == i) go to 200
-                c = c + dabs(ar(j, i)) + dabs(ai(j, i))
-                r = r + dabs(ar(i, j)) + dabs(ai(i, j))
+                c = c + abs(ar(j, i)) + abs(ai(j, i))
+                r = r + abs(ar(i, j)) + abs(ai(i, j))
 200         end do
 !     .......... guard against zero c or r due to underflow ..........
-            if (c == 0.0d0 .or. r == 0.0d0) go to 270
+            if (c == 0.0_wp .or. r == 0.0_wp) go to 270
             g = r/radix
-            f = 1.0d0
+            f = 1.0_wp
             s = c + r
 210         if (c >= g) go to 220
             f = f*radix
@@ -179,8 +181,8 @@ subroutine cbal(nm, nl, ar, ai, low, igh, scale)
             c = c/b2
             go to 230
 !     .......... now balance ..........
-240         if ((c + r)/f >= 0.95d0*s) go to 270
-            g = 1.0d0/f
+240         if ((c + r)/f >= 0.95_wp*s) go to 270
+            g = 1.0_wp/f
             scale(i) = scale(i)*f
             noconv = .true.
 
@@ -222,11 +224,11 @@ end subroutine cbal
         !! @param orti further information about the transformations
     subroutine corth(nm, nl, low, igh, ar, ai, ortr, orti)
         integer, intent(in) :: nm, nl, low, igh
-        real(kind(0d0)), dimension(nm, nl), intent(inout) :: ar, ai
-        real(kind(0d0)), dimension(igh), intent(out) :: ortr, orti
+        real(wp), dimension(nm, nl), intent(inout) :: ar, ai
+        real(wp), dimension(igh), intent(out) :: ortr, orti
 
         integer :: i, j, ml, ii, jj, la, mp, kp1, mll
-        real(kind(0d0)) :: f, g, h, fi, fr, scale, c
+        real(wp) :: f, g, h, fi, fr, scale, c
 
         mll = 6
 
@@ -235,15 +237,15 @@ subroutine corth(nm, nl, low, igh, ar, ai, ortr, orti)
         if (la < kp1) go to 200
 
         do 180 ml = kp1, la
-            h = 0.0d0
-            ortr(ml) = 0.0d0
-            orti(ml) = 0.0d0
-            scale = 0.0d0
+            h = 0.0_wp
+            ortr(ml) = 0.0_wp
+            orti(ml) = 0.0_wp
+            scale = 0.0_wp
 !     .......... scale column (algol tol then not needed) ..........
             do 90 i = ml, igh
-                scale = scale + dabs(ar(i, ml - 1)) + dabs(ai(i, ml - 1))
+                scale = scale + abs(ar(i, ml - 1)) + abs(ai(i, ml - 1))
 90          end do
-            if (scale == 0d0) go to 180
+            if (scale == 0._wp) go to 180
             mp = ml + igh
 !     .......... for i=igh step -1 until ml do -- ..........
             do 100 ii = ml, igh
@@ -253,21 +255,21 @@ subroutine corth(nm, nl, low, igh, ar, ai, ortr, orti)
                 h = h + ortr(i)*ortr(i) + orti(i)*orti(i)
 100         end do
 !
-            g = dsqrt(h)
+            g = sqrt(h)
             call pythag(ortr(ml), orti(ml), f)
-            if (f == 0d0) go to 103
+            if (f == 0._wp) go to 103
             h = h + f*g
             g = g/f
-            ortr(ml) = (1.0d0 + g)*ortr(ml)
-            orti(ml) = (1.0d0 + g)*orti(ml)
+            ortr(ml) = (1.0_wp + g)*ortr(ml)
+            orti(ml) = (1.0_wp + g)*orti(ml)
             go to 105
 
 103         ortr(ml) = g
             ar(ml, ml - 1) = scale
 !     .......... form (i-(u*ut)/h) * a ..........
 105         do 130 j = ml, nl
-                fr = 0.0d0
-                fi = 0.0d0
+                fr = 0.0_wp
+                fi = 0.0_wp
 !     .......... for i=igh step -1 until ml do -- ..........
                 do 110 ii = ml, igh
                     i = mp - ii
@@ -286,8 +288,8 @@ subroutine corth(nm, nl, low, igh, ar, ai, ortr, orti)
 130         end do
 !     .......... form (i-(u*ut)/h)*a*(i-(u*ut)/h) ..........
             do 160 i = 1, igh
-                fr = 0.0d0
-                fi = 0.0d0
+                fr = 0.0_wp
+                fi = 0.0_wp
 !     .......... for j=igh step -1 until ml do -- ..........
                 do 140 jj = ml, igh
                     j = mp - jj
@@ -344,25 +346,25 @@ end subroutine corth
         !! @param ierr an error completion code
     subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
         integer, intent(in) :: nm, nl, low, igh
-        real(kind(0d0)), dimension(nm, nl), intent(inout) :: hr, hi
-        real(kind(0d0)), dimension(nl), intent(out) :: wr, wi
-        real(kind(0d0)), dimension(nm, nl), intent(out) :: zr, zi
-        real(kind(0d0)), dimension(igh), intent(inout) :: ortr, orti
+        real(wp), dimension(nm, nl), intent(inout) :: hr, hi
+        real(wp), dimension(nl), intent(out) :: wr, wi
+        real(wp), dimension(nm, nl), intent(out) :: zr, zi
+        real(wp), dimension(igh), intent(inout) :: ortr, orti
         integer, intent(out) :: ierr
 
         integer :: i, j, k, l, ml, en, ii, jj, ll, nn, ip1, itn, its, lp1, enm1, iend
-        real(kind(0d0)) :: si, sr, ti, tr, xi, xr, xxi, xxr, yi, yr, zzi, zzr, &
-                           norm, tst1, tst2, c, d
+        real(wp) :: si, sr, ti, tr, xi, xr, xxi, xxr, yi, yr, zzi, zzr, &
+                    norm, tst1, tst2, c, d
 !
         ierr = 0
 !     .......... initialize eigenvector matrix ..........
         do 101 j = 1, nl
 !
             do 100 i = 1, nl
-                zr(i, j) = 0.0d0
-                zi(i, j) = 0.0d0
+                zr(i, j) = 0.0_wp
+                zi(i, j) = 0.0_wp
 100         end do
-            zr(j, j) = 1.0d0
+            zr(j, j) = 1.0_wp
 101     end do
 !     .......... form the matrix of accumulated transformations
 !                from the information left by corth ..........
@@ -373,8 +375,8 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 !     .......... for i=igh-1 step -1 until low+1 do -- ..........
 105     do 140 ii = 1, iend
             i = igh - ii
-            if (dabs(ortr(i)) == 0d0 .and. dabs(orti(i)) == 0d0) go to 140
-            if (dabs(hr(i, i - 1)) == 0d0 .and. dabs(hi(i, i - 1)) == 0d0) go to 140
+            if (abs(ortr(i)) == 0._wp .and. abs(orti(i)) == 0._wp) go to 140
+            if (abs(hr(i, i - 1)) == 0._wp .and. abs(hi(i, i - 1)) == 0._wp) go to 140
 !     .......... norm below is negative of h formed in corth ..........
             norm = hr(i, i - 1)*ortr(i) + hi(i, i - 1)*orti(i)
             ip1 = i + 1
@@ -385,8 +387,8 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 110         end do
 !
             do 130 j = i, igh
-                sr = 0.0d0
-                si = 0.0d0
+                sr = 0.0_wp
+                si = 0.0_wp
 !
                 do 115 k = i, igh
                     sr = sr + ortr(k)*zr(k, j) + orti(k)*zi(k, j)
@@ -409,12 +411,12 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 !
         do 170 i = l, igh
             ll = min0(i + 1, igh)
-            if (dabs(hi(i, i - 1)) == 0d0) go to 170
+            if (abs(hi(i, i - 1)) == 0._wp) go to 170
             call pythag(hr(i, i - 1), hi(i, i - 1), norm)
             yr = hr(i, i - 1)/norm
             yi = hi(i, i - 1)/norm
             hr(i, i - 1) = norm
-            hi(i, i - 1) = 0.0d0
+            hi(i, i - 1) = 0.0_wp
 !
             do 155 j = i, nl
                 si = yr*hi(i, j) - yi*hr(i, j)
@@ -442,8 +444,8 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 200     end do
 !
         en = igh
-        tr = 0.0d0
-        ti = 0.0d0
+        tr = 0.0_wp
+        ti = 0.0_wp
         itn = 30*nl
 !     .......... search for next eigenvalue ..........
 220     if (en < low) go to 680
@@ -454,9 +456,9 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 240     do 260 ll = low, en
             l = en + low - ll
             if (l == low) go to 300
-            tst1 = dabs(hr(l - 1, l - 1)) + dabs(hi(l - 1, l - 1)) &
-                   + dabs(hr(l, l)) + dabs(hi(l, l))
-            tst2 = tst1 + dabs(hr(l, l - 1))
+            tst1 = abs(hr(l - 1, l - 1)) + abs(hi(l - 1, l - 1)) &
+                   + abs(hr(l, l)) + abs(hi(l, l))
+            tst2 = tst1 + abs(hr(l, l - 1))
             if (tst2 == tst1) go to 300
 260     end do
 !     .......... form shift ..........
@@ -467,11 +469,11 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
         si = hi(en, en)
         xr = hr(enm1, en)*hr(en, enm1)
         xi = hi(enm1, en)*hr(en, enm1)
-        if (xr == 0.0d0 .and. xi == 0.0d0) go to 340
-        yr = (hr(enm1, enm1) - sr)/2.0d0
-        yi = (hi(enm1, enm1) - si)/2.0d0
-        call csroot(yr**2 - yi**2 + xr, 2.0d0*yr*yi + xi, zzr, zzi)
-        if (yr*zzr + yi*zzi >= 0.0d0) go to 310
+        if (xr == 0.0_wp .and. xi == 0.0_wp) go to 340
+        yr = (hr(enm1, enm1) - sr)/2.0_wp
+        yi = (hi(enm1, enm1) - si)/2.0_wp
+        call csroot(yr**2 - yi**2 + xr, 2.0_wp*yr*yi + xi, zzr, zzi)
+        if (yr*zzr + yi*zzi >= 0.0_wp) go to 310
         zzr = -zzr
         zzi = -zzi
 310     call cdiv(xr, xi, yr + zzr, yi + zzi, xxr, xxi)
@@ -479,8 +481,8 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
         si = si - xxi
         go to 340
 !     .......... form exceptional shift ..........
-320     sr = dabs(hr(en, enm1)) + dabs(hr(enm1, en - 2))
-        si = 0.0d0
+320     sr = abs(hr(en, enm1)) + abs(hr(enm1, en - 2))
+        si = 0.0_wp
 !
 340     do 360 i = low, en
             hr(i, i) = hr(i, i) - sr
@@ -496,7 +498,7 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 !
         do 500 i = lp1, en
             sr = hr(i, i - 1)
-            hr(i, i - 1) = 0.0d0
+            hr(i, i - 1) = 0.0_wp
             call pythag(hr(i - 1, i - 1), hi(i - 1, i - 1), c)
             call pythag(c, sr, norm)
             xr = hr(i - 1, i - 1)/norm
@@ -504,7 +506,7 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
             xi = hi(i - 1, i - 1)/norm
             wi(i - 1) = xi
             hr(i - 1, i - 1) = norm
-            hi(i - 1, i - 1) = 0.0d0
+            hi(i - 1, i - 1) = 0.0_wp
             hi(i, i - 1) = sr/norm
 !
             do 490 j = i, nl
@@ -521,12 +523,12 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 500     end do
 !
         si = hi(en, en)
-        if (dabs(si) == 0d0) go to 540
+        if (abs(si) == 0._wp) go to 540
         call pythag(hr(en, en), si, norm)
         sr = hr(en, en)/norm
         si = si/norm
         hr(en, en) = norm
-        hi(en, en) = 0.0d0
+        hi(en, en) = 0.0_wp
         if (en == nl) go to 540
         ip1 = en + 1
 !
@@ -543,7 +545,7 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 !
             do 580 i = 1, j
                 yr = hr(i, j - 1)
-                yi = 0.0d0
+                yi = 0.0_wp
                 zzr = hr(i, j)
                 zzi = hi(i, j)
                 if (i == j) go to 560
@@ -566,7 +568,7 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 590         end do
 600     end do
 !
-        if (dabs(si) == 0d0) go to 240
+        if (abs(si) == 0._wp) go to 240
 !
         do 630 i = 1, en
             yr = hr(i, en)
@@ -592,29 +594,29 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
         go to 220
 !     .......... all roots found.  backsubstitute to find
 !                vectors of upper triangular form ..........
-680     norm = 0.0d0
+680     norm = 0.0_wp
 !
         do i = 1, nl
             do j = i, nl
-                tr = dabs(hr(i, j)) + dabs(hi(i, j))
+                tr = abs(hr(i, j)) + abs(hi(i, j))
                 if (tr > norm) norm = tr
             end do
         end do
 !
-        if (nl == 1 .or. norm == 0d0) go to 1001
+        if (nl == 1 .or. norm == 0._wp) go to 1001
 !     .......... for en=nl step -1 until 2 do -- ..........
         do 800 nn = 2, nl
             en = nl + 2 - nn
             xr = wr(en)
             xi = wi(en)
-            hr(en, en) = 1.0d0
-            hi(en, en) = 0.0d0
+            hr(en, en) = 1.0_wp
+            hi(en, en) = 0.0_wp
             enm1 = en - 1
 !     .......... for i=en-1 step -1 until 1 do -- ..........
             do 780 ii = 1, enm1
                 i = en - ii
-                zzr = 0.0d0
-                zzi = 0.0d0
+                zzr = 0.0_wp
+                zzi = 0.0_wp
                 ip1 = i + 1
 
                 do 740 j = ip1, en
@@ -624,19 +626,19 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
 !
                 yr = xr - wr(i)
                 yi = xi - wi(i)
-                if (yr /= 0.0d0 .or. yi /= 0.0d0) go to 765
+                if (yr /= 0.0_wp .or. yi /= 0.0_wp) go to 765
                 tst1 = norm
                 yr = tst1
-760             yr = 0.01d0*yr
+760             yr = 0.01_wp*yr
                 tst2 = norm + yr
                 if (tst2 > tst1) go to 760
 765             continue
                 call cdiv(zzr, zzi, yr, yi, hr(i, en), hi(i, en))
 !     .......... overflow control ..........
-                tr = dabs(hr(i, en)) + dabs(hi(i, en))
-                if (tr == 0.0d0) go to 780
+                tr = abs(hr(i, en)) + abs(hi(i, en))
+                if (tr == 0.0_wp) go to 780
                 tst1 = tr
-                tst2 = tst1 + 1.0d0/tst1
+                tst2 = tst1 + 1.0_wp/tst1
                 if (tst2 > tst1) go to 780
                 do 770 j = i, en
                     hr(j, en) = hr(j, en)/tr
@@ -665,8 +667,8 @@ subroutine comqr2(nm, nl, low, igh, ortr, orti, hr, hi, wr, wi, zr, zi, ierr)
             ml = min0(j, igh)
 !
             do i = low, igh
-                zzr = 0.0d0
-                zzi = 0.0d0
+                zzr = 0.0_wp
+                zzi = 0.0_wp
 !
                 do 860 k = low, ml
                     zzr = zzr + zr(i, k)*hr(k, j) - zi(i, k)*hi(k, j)
@@ -707,12 +709,12 @@ end subroutine comqr2
         !!           transformed in their first ml columns
     subroutine cbabk2(nm, nl, low, igh, scale, ml, zr, zi)
         integer, intent(in) :: nm, nl, low, igh
-        double precision, intent(in) :: scale(nl)
+        real(wp), intent(in) :: scale(nl)
         integer, intent(in) :: ml
-        double precision, intent(inout) :: zr(nm, ml), zi(nm, ml)
+        real(wp), intent(inout) :: zr(nm, ml), zi(nm, ml)
 
         integer :: i, j, k, ii
-        double precision :: s
+        real(wp) :: s
 
         if (ml == 0) go to 200
         if (igh == low) go to 120
@@ -721,7 +723,7 @@ subroutine cbabk2(nm, nl, low, igh, scale, ml, zr, zi)
             s = scale(i)
 !     .......... left hand eigenvectors are back transformed
 !                if the foregoing statement is replaced by
-!                s=1.0d0/scale(i). ..........
+!                s=1.0_wp/scale(i). ..........
             do 100 j = 1, ml
                 zr(i, j) = zr(i, j)*s
                 zi(i, j) = zi(i, j)*s
@@ -752,66 +754,66 @@ subroutine cbabk2(nm, nl, low, igh, scale, ml, zr, zi)
     end subroutine cbabk2
 
     subroutine csroot(xr, xi, yr, yi)
-        real(kind(0d0)), intent(in) :: xr, xi
-        real(kind(0d0)), intent(out) :: yr, yi
+        real(wp), intent(in) :: xr, xi
+        real(wp), intent(out) :: yr, yi
 !
-!     (yr,yi) = complex dsqrt(xr,xi)
+!     (yr,yi) = complex sqrt(xr,xi)
 !     branch chosen so that yr .ge. 0.0 and sign(yi) .eq. sign(xi)
 !
-        real(kind(0d0)) :: s, tr, ti, c
+        real(wp) :: s, tr, ti, c
         tr = xr
         ti = xi
         call pythag(tr, ti, c)
-        s = dsqrt(0.5d0*(c + dabs(tr)))
-        if (tr >= 0.0d0) yr = s
-        if (ti < 0.0d0) s = -s
-        if (tr <= 0.0d0) yi = s
-        if (tr < 0.0d0) yr = 0.5d0*(ti/yi)
-        if (tr > 0.0d0) yi = 0.5d0*(ti/yr)
+        s = sqrt(0.5_wp*(c + abs(tr)))
+        if (tr >= 0.0_wp) yr = s
+        if (ti < 0.0_wp) s = -s
+        if (tr <= 0.0_wp) yi = s
+        if (tr < 0.0_wp) yr = 0.5_wp*(ti/yi)
+        if (tr > 0.0_wp) yi = 0.5_wp*(ti/yr)
         return
     end subroutine csroot
 
     subroutine cdiv(ar, ai, br, bi, cr, ci)
-        real(kind(0d0)), intent(in) :: ar, ai, br, bi
-        real(kind(0d0)), intent(out) :: cr, ci
-        real(kind(0d0)) :: s, ars, ais, brs, bis
+        real(wp), intent(in) :: ar, ai, br, bi
+        real(wp), intent(out) :: cr, ci
+        real(wp) :: s, ars, ais, brs, bis
 !
 !     complex division, (cr,ci) = (ar,ai)/(br,bi)
 !
         ! (ar + i*ai) * (br - i*bi) /(br**2 + bi**2)
         ! ((ar*br + i*ai*br) + (-i*ar*bi + ai*bi)) /(br**2 + bi**2)
         ! (ar*br + ai*bi + i*(ai*br - ar*bi)) /(br**2 + bi**2)
-        ! cr = (ar*br + ai*bi) / (br**2d0 + bi**2d0)
-        ! ci = (ai*br - ar*bi) / (br**2d0 + bi**2d0)
+        ! cr = (ar*br + ai*bi) / (br**2._wp + bi**2._wp)
+        ! ci = (ai*br - ar*bi) / (br**2._wp + bi**2._wp)
 
-        s = dabs(br) + dabs(bi)
+        s = abs(br) + abs(bi)
         ars = ar/s
         ais = ai/s
         brs = br/s
         bis = bi/s
-        s = brs**2d0 + bis**2d0
+        s = brs**2._wp + bis**2._wp
         cr = (ars*brs + ais*bis)/s
         ci = (ais*brs - ars*bis)/s
         return
     end subroutine cdiv
 
     subroutine pythag(a, b, c)
-        real(kind(0d0)), intent(in) :: a, b
-        real(kind(0d0)), intent(out) :: c
+        real(wp), intent(in) :: a, b
+        real(wp), intent(out) :: c
 !
-!     finds dsqrt(a**2+b**2) without overflow or destructive underflow
+!     finds sqrt(a**2+b**2) without overflow or destructive underflow
 !
-        real(kind(0d0)) :: p, r, s, t, u
-        p = dmax1(dabs(a), dabs(b))
-        if (p == 0.0d0) go to 20
-        r = (dmin1(dabs(a), dabs(b))/p)**2
+        real(wp) :: p, r, s, t, u
+        p = max(abs(a), abs(b))
+        if (p == 0.0_wp) go to 20
+        r = (min(abs(a), abs(b))/p)**2
 10      continue
-        t = 4.0d0 + r
-        if (t == 4.0d0) go to 20
+        t = 4.0_wp + r
+        if (t == 4.0_wp) go to 20
         s = r/t
-        u = 1.0d0 + 2.0d0*s
+        u = 1.0_wp + 2.0_wp*s
         p = u*p
-        r = (s/u)**2d0*r
+        r = (s/u)**2._wp*r
         go to 10
 20      c = p
         return
diff --git a/src/common/m_finite_differences.fpp b/src/common/m_finite_differences.fpp
index 9eb65a121..fd0323a79 100644
--- a/src/common/m_finite_differences.fpp
+++ b/src/common/m_finite_differences.fpp
@@ -14,7 +14,7 @@ contains
 
         integer :: x, y, z !< Generic loop iterators
 
-        real(kind(0d0)) :: divergence
+        real(wp) :: divergence
 
         !$acc parallel loop collapse(3) private(divergence)
         do x = ix_s%beg, ix_s%end
@@ -22,18 +22,18 @@ contains
                 do z = iz_s%beg, iz_s%end
 
                     if (x == ix_s%beg) then
-                        divergence = (-3d0*fields(1)%sf(x, y, z) + 4d0*fields(1)%sf(x + 1, y, z) - fields(1)%sf(x + 2, y, z))/(x_cc(x + 2) - x_cc(x))
+                        divergence = (-3._wp*fields(1)%sf(x, y, z) + 4._wp*fields(1)%sf(x + 1, y, z) - fields(1)%sf(x + 2, y, z))/(x_cc(x + 2) - x_cc(x))
                     else if (x == ix_s%end) then
-                        divergence = (+3d0*fields(1)%sf(x, y, z) - 4d0*fields(1)%sf(x - 1, y, z) + fields(1)%sf(x - 2, y, z))/(x_cc(x) - x_cc(x - 2))
+                        divergence = (+3._wp*fields(1)%sf(x, y, z) - 4._wp*fields(1)%sf(x - 1, y, z) + fields(1)%sf(x - 2, y, z))/(x_cc(x) - x_cc(x - 2))
                     else
                         divergence = (fields(1)%sf(x + 1, y, z) - fields(1)%sf(x - 1, y, z))/(x_cc(x + 1) - x_cc(x - 1))
                     end if
 
                     if (n > 0) then
                         if (y == iy_s%beg) then
-                            divergence = divergence + (-3d0*fields(2)%sf(x, y, z) + 4d0*fields(2)%sf(x, y + 1, z) - fields(2)%sf(x, y + 2, z))/(y_cc(y + 2) - y_cc(y))
+                            divergence = divergence + (-3._wp*fields(2)%sf(x, y, z) + 4._wp*fields(2)%sf(x, y + 1, z) - fields(2)%sf(x, y + 2, z))/(y_cc(y + 2) - y_cc(y))
                         else if (y == iy_s%end) then
-                            divergence = divergence + (+3d0*fields(2)%sf(x, y, z) - 4d0*fields(2)%sf(x, y - 1, z) + fields(2)%sf(x, y - 2, z))/(y_cc(y) - y_cc(y - 2))
+                            divergence = divergence + (+3._wp*fields(2)%sf(x, y, z) - 4._wp*fields(2)%sf(x, y - 1, z) + fields(2)%sf(x, y - 2, z))/(y_cc(y) - y_cc(y - 2))
                         else
                             divergence = divergence + (fields(2)%sf(x, y + 1, z) - fields(2)%sf(x, y - 1, z))/(y_cc(y + 1) - y_cc(y - 1))
                         end if
@@ -41,9 +41,9 @@ contains
 
                     if (p > 0) then
                         if (z == iz_s%beg) then
-                            divergence = divergence + (-3d0*fields(3)%sf(x, y, z) + 4d0*fields(3)%sf(x, y, z + 1) - fields(3)%sf(x, y, z + 2))/(z_cc(z + 2) - z_cc(z))
+                            divergence = divergence + (-3._wp*fields(3)%sf(x, y, z) + 4._wp*fields(3)%sf(x, y, z + 1) - fields(3)%sf(x, y, z + 2))/(z_cc(z + 2) - z_cc(z))
                         else if (z == iz_s%end) then
-                            divergence = divergence + (+3d0*fields(3)%sf(x, y, z) - 4d0*fields(3)%sf(x, y, z - 1) + fields(2)%sf(x, y, z - 2))/(z_cc(z) - z_cc(z - 2))
+                            divergence = divergence + (+3._wp*fields(3)%sf(x, y, z) - 4._wp*fields(3)%sf(x, y, z - 1) + fields(2)%sf(x, y, z - 2))/(z_cc(z) - z_cc(z - 2))
                         else
                             divergence = divergence + (fields(3)%sf(x, y, z + 1) - fields(3)%sf(x, y, z - 1))/(z_cc(z + 1) - z_cc(z - 1))
                         end if
@@ -74,9 +74,9 @@ contains
         integer, intent(IN) :: q
         integer, intent(IN) :: buff_size, fd_number_in, fd_order_in
         type(int_bounds_info), optional, intent(IN) :: offset_s
-        real(kind(0d0)), allocatable, dimension(:, :), intent(INOUT) :: fd_coeff_s
+        real(wp), allocatable, dimension(:, :), intent(INOUT) :: fd_coeff_s
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-buff_size:q + buff_size), &
             intent(IN) :: s_cc
 
@@ -96,25 +96,25 @@ contains
         ! Computing the 1st order finite-difference coefficients
         if (fd_order_in == 1) then
             do i = lB, lE
-                fd_coeff_s(-1, i) = 0d0
-                fd_coeff_s(0, i) = -1d0/(s_cc(i + 1) - s_cc(i))
+                fd_coeff_s(-1, i) = 0._wp
+                fd_coeff_s(0, i) = -1._wp/(s_cc(i + 1) - s_cc(i))
                 fd_coeff_s(1, i) = -fd_coeff_s(0, i)
             end do
 
             ! Computing the 2nd order finite-difference coefficients
         elseif (fd_order_in == 2) then
             do i = lB, lE
-                fd_coeff_s(-1, i) = -1d0/(s_cc(i + 1) - s_cc(i - 1))
-                fd_coeff_s(0, i) = 0d0
+                fd_coeff_s(-1, i) = -1._wp/(s_cc(i + 1) - s_cc(i - 1))
+                fd_coeff_s(0, i) = 0._wp
                 fd_coeff_s(1, i) = -fd_coeff_s(-1, i)
             end do
 
             ! Computing the 4th order finite-difference coefficients
         else
             do i = lB, lE
-                fd_coeff_s(-2, i) = 1d0/(s_cc(i - 2) - 8d0*s_cc(i - 1) - s_cc(i + 2) + 8d0*s_cc(i + 1))
-                fd_coeff_s(-1, i) = -8d0*fd_coeff_s(-2, i)
-                fd_coeff_s(0, i) = 0d0
+                fd_coeff_s(-2, i) = 1._wp/(s_cc(i - 2) - 8._wp*s_cc(i - 1) - s_cc(i + 2) + 8._wp*s_cc(i + 1))
+                fd_coeff_s(-1, i) = -8._wp*fd_coeff_s(-2, i)
+                fd_coeff_s(0, i) = 0._wp
                 fd_coeff_s(1, i) = -fd_coeff_s(-1, i)
                 fd_coeff_s(2, i) = -fd_coeff_s(-2, i)
             end do
diff --git a/src/common/m_helper.fpp b/src/common/m_helper.fpp
index dce271120..7daf79310 100644
--- a/src/common/m_helper.fpp
+++ b/src/common/m_helper.fpp
@@ -46,43 +46,40 @@ contains
         !! @param ntmp is the output number bubble density
     subroutine s_comp_n_from_prim(vftmp, Rtmp, ntmp, weights)
         !$acc routine seq
-        real(kind(0.d0)), intent(in) :: vftmp
-        real(kind(0.d0)), dimension(nb), intent(in) :: Rtmp
-        real(kind(0.d0)), intent(out) :: ntmp
-        real(kind(0.d0)), dimension(nb), intent(in) :: weights
+        real(wp), intent(in) :: vftmp
+        real(wp), dimension(nb), intent(in) :: Rtmp
+        real(wp), intent(out) :: ntmp
+        real(wp), dimension(nb), intent(in) :: weights
 
-        real(kind(0.d0)) :: R3
+        real(wp) :: R3
 
-        R3 = dot_product(weights, Rtmp**3.d0)
-        ntmp = (3.d0/(4.d0*pi))*vftmp/R3
+        R3 = dot_product(weights, Rtmp**3._wp)
+        ntmp = (3._wp/(4._wp*pi))*vftmp/R3
 
     end subroutine s_comp_n_from_prim
 
     subroutine s_comp_n_from_cons(vftmp, nRtmp, ntmp, weights)
         !$acc routine seq
-        real(kind(0.d0)), intent(in) :: vftmp
-        real(kind(0.d0)), dimension(nb), intent(in) :: nRtmp
-        real(kind(0.d0)), intent(out) :: ntmp
-        real(kind(0.d0)), dimension(nb), intent(in) :: weights
+        real(wp), intent(in) :: vftmp
+        real(wp), dimension(nb), intent(in) :: nRtmp
+        real(wp), intent(out) :: ntmp
+        real(wp), dimension(nb), intent(in) :: weights
 
-        real(kind(0.d0)) :: nR3
+        real(wp) :: nR3
 
-        nR3 = dot_product(weights, nRtmp**3.d0)
-        ntmp = DSQRT((4.d0*pi/3.d0)*nR3/vftmp)
-        !ntmp = (3.d0/(4.d0*pi))*0.00001
-
-        !print *, "nbub", ntmp
+        nR3 = dot_product(weights, nRtmp**3._wp)
+        ntmp = sqrt((4._wp*pi/3._wp)*nR3/vftmp)
 
     end subroutine s_comp_n_from_cons
 
     subroutine s_print_2D_array(A, div)
 
-        real(kind(0d0)), dimension(:, :), intent(in) :: A
-        real, optional, intent(in) :: div
+        real(wp), dimension(:, :), intent(in) :: A
+        real(wp), optional, intent(in) :: div
 
         integer :: i, j
         integer :: m, n
-        real :: c
+        real(wp) :: c
 
         m = size(A, 1)
         n = size(A, 2)
@@ -90,7 +87,7 @@ contains
         if (present(div)) then
             c = div
         else
-            c = 1
+            c = 1._wp
         end if
 
         print *, m, n
@@ -109,13 +106,13 @@ contains
     subroutine s_initialize_nonpoly
 
         integer :: ir
-        real(kind(0.d0)) :: rhol0, pl0, uu, D_m, temp, omega_ref
-        real(kind(0.d0)), dimension(Nb) :: chi_vw0, cp_m0, k_m0, rho_m0, x_vw
+        real(wp) :: rhol0, pl0, uu, D_m, temp, omega_ref
+        real(wp), dimension(Nb) :: chi_vw0, cp_m0, k_m0, rho_m0, x_vw
 
-        real(kind(0.d0)), parameter :: k_poly = 1.d0 !<
+        real(wp), parameter :: k_poly = 1._wp !<
             !! polytropic index used to compute isothermal natural frequency
 
-        real(kind(0.d0)), parameter :: Ru = 8314.d0 !<
+        real(wp), parameter :: Ru = 8314._wp !<
             !! universal gas constant
 
         rhol0 = rhoref
@@ -150,42 +147,42 @@ contains
         k_n(:) = fluid_pp(2)%k_v
 
         gamma_m = gamma_n
-        if (thermal == 2) gamma_m = 1.d0
+        if (thermal == 2) gamma_m = 1._wp
 
-        temp = 293.15d0
-        D_m = 0.242d-4
-        uu = DSQRT(pl0/rhol0)
+        temp = 293.15_wp
+        D_m = 0.242e-4_wp
+        uu = sqrt(pl0/rhol0)
 
-        omega_ref = 3.d0*k_poly*Ca + 2.d0*(3.d0*k_poly - 1.d0)/Web
+        omega_ref = 3._wp*k_poly*Ca + 2._wp*(3._wp*k_poly - 1._wp)/Web
 
             !!! thermal properties !!!
         ! gas constants
         R_n = Ru/M_n
         R_v = Ru/M_v
         ! phi_vn & phi_nv (phi_nn = phi_vv = 1)
-        phi_vn = (1.d0 + DSQRT(mu_v/mu_n)*(M_n/M_v)**(0.25d0))**2 &
-                 /(DSQRT(8.d0)*DSQRT(1.d0 + M_v/M_n))
-        phi_nv = (1.d0 + DSQRT(mu_n/mu_v)*(M_v/M_n)**(0.25d0))**2 &
-                 /(DSQRT(8.d0)*DSQRT(1.d0 + M_n/M_v))
+        phi_vn = (1._wp + sqrt(mu_v/mu_n)*(M_n/M_v)**(0.25_wp))**2 &
+                 /(sqrt(8._wp)*sqrt(1._wp + M_v/M_n))
+        phi_nv = (1._wp + sqrt(mu_n/mu_v)*(M_v/M_n)**(0.25_wp))**2 &
+                 /(sqrt(8._wp)*sqrt(1._wp + M_n/M_v))
         ! internal bubble pressure
-        pb0 = pl0 + 2.d0*ss/(R0ref*R0)
+        pb0 = pl0 + 2._wp*ss/(R0ref*R0)
 
         ! mass fraction of vapor
-        chi_vw0 = 1.d0/(1.d0 + R_v/R_n*(pb0/pv - 1.d0))
+        chi_vw0 = 1._wp/(1._wp + R_v/R_n*(pb0/pv - 1._wp))
         ! specific heat for gas/vapor mixture
-        cp_m0 = chi_vw0*R_v*gamma_v/(gamma_v - 1.d0) &
-                + (1.d0 - chi_vw0)*R_n*gamma_n/(gamma_n - 1.d0)
+        cp_m0 = chi_vw0*R_v*gamma_v/(gamma_v - 1._wp) &
+                + (1._wp - chi_vw0)*R_n*gamma_n/(gamma_n - 1._wp)
         ! mole fraction of vapor
         x_vw = M_n*chi_vw0/(M_v + (M_n - M_v)*chi_vw0)
         ! thermal conductivity for gas/vapor mixture
-        k_m0 = x_vw*k_v/(x_vw + (1.d0 - x_vw)*phi_vn) &
-               + (1.d0 - x_vw)*k_n/(x_vw*phi_nv + 1.d0 - x_vw)
+        k_m0 = x_vw*k_v/(x_vw + (1._wp - x_vw)*phi_vn) &
+               + (1._wp - x_vw)*k_n/(x_vw*phi_nv + 1._wp - x_vw)
         ! mixture density
         rho_m0 = pv/(chi_vw0*R_v*temp)
 
         ! mass of gas/vapor computed using dimensional quantities
-        mass_n0 = 4.d0*(pb0 - pv)*pi/(3.d0*R_n*temp*rhol0)*R0**3
-        mass_v0 = 4.d0*pv*pi/(3.d0*R_v*temp*rhol0)*R0**3
+        mass_n0 = 4._wp*(pb0 - pv)*pi/(3._wp*R_n*temp*rhol0)*R0**3
+        mass_v0 = 4._wp*pv*pi/(3._wp*R_v*temp*rhol0)*R0**3
         ! Peclet numbers
         Pe_T = rho_m0*cp_m0*uu*R0ref/k_m0
         Pe_c = uu*R0ref/D_m
@@ -200,22 +197,22 @@ contains
         k_v = k_v/k_m0
         pb0 = pb0/pl0
         pv = pv/pl0
-        Tw = 1.d0
-        pl0 = 1.d0
+        Tw = 1._wp
+        pl0 = 1._wp
 
-        rhoref = 1.d0
-        pref = 1.d0
+        rhoref = 1._wp
+        pref = 1._wp
         !end if
 
         ! natural frequencies
-        omegaN = DSQRT(3.d0*k_poly*Ca + 2.d0*(3.d0*k_poly - 1.d0)/(Web*R0))/R0
+        omegaN = sqrt(3._wp*k_poly*Ca + 2._wp*(3._wp*k_poly - 1._wp)/(Web*R0))/R0
         do ir = 1, Nb
             call s_transcoeff(omegaN(ir)*R0(ir), Pe_T(ir)*R0(ir), &
                               Re_trans_T(ir), Im_trans_T(ir))
             call s_transcoeff(omegaN(ir)*R0(ir), Pe_c*R0(ir), &
                               Re_trans_c(ir), Im_trans_c(ir))
         end do
-        Im_trans_T = 0d0
+        Im_trans_T = 0._wp
 
     end subroutine s_initialize_nonpoly
 
@@ -226,19 +223,19 @@ contains
         !! @param Im_trans Imaginary part of the transport coefficients
     subroutine s_transcoeff(omega, peclet, Re_trans, Im_trans)
 
-        real(kind(0.d0)), intent(in) :: omega, peclet
-        real(kind(0.d0)), intent(out) :: Re_trans, Im_trans
+        real(wp), intent(in) :: omega, peclet
+        real(wp), intent(out) :: Re_trans, Im_trans
 
         complex :: trans, c1, c2, c3
-        complex :: imag = (0., 1.)
-        real(kind(0.d0)) :: f_transcoeff
+        complex :: imag = (0._wp, 1._wp)
+        real(wp) :: f_transcoeff
 
         c1 = imag*omega*peclet
-        c2 = CSQRT(c1)
-        c3 = (CEXP(c2) - CEXP(-c2))/(CEXP(c2) + CEXP(-c2)) ! TANH(c2)
-        trans = ((c2/c3 - 1.d0)**(-1) - 3.d0/c1)**(-1) ! transfer function
+        c2 = csqrt(c1)
+        c3 = (cexp(c2) - cexp(-c2))/(cexp(c2) + cexp(-c2)) ! TANH(c2)
+        trans = ((c2/c3 - 1._wp)**(-1) - 3._wp/c1)**(-1) ! transfer function
 
-        Re_trans = dble(trans)
+        Re_trans = trans
         Im_trans = aimag(trans)
 
     end subroutine s_transcoeff
@@ -256,48 +253,35 @@ contains
     subroutine s_simpson
 
         integer :: ir
-        real(kind(0.d0)) :: R0mn, R0mx, dphi, tmp, sd
-        real(kind(0.d0)), dimension(nb) :: phi
-
-        ! nondiml. min. & max. initial radii for numerical quadrature
-        !sd   = 0.05D0
-        !R0mn = 0.75D0
-        !R0mx = 1.3D0
-
-        !sd   = 0.3D0
-        !R0mn = 0.3D0
-        !R0mx = 6.D0
-
-        !sd   = 0.7D0
-        !R0mn = 0.12D0
-        !R0mx = 150.D0
+        real(wp) :: R0mn, R0mx, dphi, tmp, sd
+        real(wp), dimension(nb) :: phi
 
         sd = poly_sigma
-        R0mn = 0.8d0*DEXP(-2.8d0*sd)
-        R0mx = 0.2d0*DEXP(9.5d0*sd) + 1.d0
+        R0mn = 0.8_wp*exp(-2.8_wp*sd)
+        R0mx = 0.2_wp*exp(9.5_wp*sd) + 1._wp
 
         ! phi = ln( R0 ) & return R0
         do ir = 1, nb
-            phi(ir) = DLOG(R0mn) &
-                      + dble(ir - 1)*DLOG(R0mx/R0mn)/dble(nb - 1)
-            R0(ir) = DEXP(phi(ir))
+            phi(ir) = log(R0mn) &
+                      + (ir - 1._wp)*log(R0mx/R0mn)/(nb - 1._wp)
+            R0(ir) = exp(phi(ir))
         end do
         dphi = phi(2) - phi(1)
 
         ! weights for quadrature using Simpson's rule
         do ir = 2, nb - 1
             ! Gaussian
-            tmp = DEXP(-0.5d0*(phi(ir)/sd)**2)/DSQRT(2.d0*pi)/sd
+            tmp = exp(-0.5_wp*(phi(ir)/sd)**2)/sqrt(2._wp*pi)/sd
             if (mod(ir, 2) == 0) then
-                weight(ir) = tmp*4.d0*dphi/3.d0
+                weight(ir) = tmp*4._wp*dphi/3._wp
             else
-                weight(ir) = tmp*2.d0*dphi/3.d0
+                weight(ir) = tmp*2._wp*dphi/3._wp
             end if
         end do
-        tmp = DEXP(-0.5d0*(phi(1)/sd)**2)/DSQRT(2.d0*pi)/sd
-        weight(1) = tmp*dphi/3.d0
-        tmp = DEXP(-0.5d0*(phi(nb)/sd)**2)/DSQRT(2.d0*pi)/sd
-        weight(nb) = tmp*dphi/3.d0
+        tmp = exp(-0.5_wp*(phi(1)/sd)**2)/sqrt(2._wp*pi)/sd
+        weight(1) = tmp*dphi/3._wp
+        tmp = exp(-0.5_wp*(phi(nb)/sd)**2)/sqrt(2._wp*pi)/sd
+        weight(nb) = tmp*dphi/3._wp
     end subroutine s_simpson
 
     !> This procedure computes the cross product of two vectors.
@@ -306,8 +290,8 @@ contains
     !! @return The cross product of the two vectors.
     function f_cross(a, b) result(c)
 
-        real(kind(0d0)), dimension(3), intent(in) :: a, b
-        real(kind(0d0)), dimension(3) :: c
+        real(wp), dimension(3), intent(in) :: a, b
+        real(wp), dimension(3) :: c
 
         c(1) = a(2)*b(3) - a(3)*b(2)
         c(2) = a(3)*b(1) - a(1)*b(3)
@@ -319,8 +303,8 @@ contains
     !! @param rhs Right-hand side.
     subroutine s_swap(lhs, rhs)
 
-        real(kind(0d0)), intent(inout) :: lhs, rhs
-        real(kind(0d0)) :: ltemp
+        real(wp), intent(inout) :: lhs, rhs
+        real(wp) :: ltemp
 
         ltemp = lhs
         lhs = rhs
@@ -336,34 +320,34 @@ contains
         t_mat4x4 :: sc, rz, rx, ry, tr, out_matrix
 
         sc = transpose(reshape([ &
-                               p%scale(1), 0d0, 0d0, 0d0, &
-                               0d0, p%scale(2), 0d0, 0d0, &
-                               0d0, 0d0, p%scale(3), 0d0, &
-                               0d0, 0d0, 0d0, 1d0], shape(sc)))
+                               p%scale(1), 0._wp, 0._wp, 0._wp, &
+                               0._wp, p%scale(2), 0._wp, 0._wp, &
+                               0._wp, 0._wp, p%scale(3), 0._wp, &
+                               0._wp, 0._wp, 0._wp, 1._wp], shape(sc)))
 
         rz = transpose(reshape([ &
-                               cos(p%rotate(3)), -sin(p%rotate(3)), 0d0, 0d0, &
-                               sin(p%rotate(3)), cos(p%rotate(3)), 0d0, 0d0, &
-                               0d0, 0d0, 1d0, 0d0, &
-                               0d0, 0d0, 0d0, 1d0], shape(rz)))
+                               cos(p%rotate(3)), -sin(p%rotate(3)), 0._wp, 0._wp, &
+                               sin(p%rotate(3)), cos(p%rotate(3)), 0._wp, 0._wp, &
+                               0._wp, 0._wp, 1._wp, 0._wp, &
+                               0._wp, 0._wp, 0._wp, 1._wp], shape(rz)))
 
         rx = transpose(reshape([ &
-                               1d0, 0d0, 0d0, 0d0, &
-                               0d0, cos(p%rotate(1)), -sin(p%rotate(1)), 0d0, &
-                               0d0, sin(p%rotate(1)), cos(p%rotate(1)), 0d0, &
-                               0d0, 0d0, 0d0, 1d0], shape(rx)))
+                               1._wp, 0._wp, 0._wp, 0._wp, &
+                               0._wp, cos(p%rotate(1)), -sin(p%rotate(1)), 0._wp, &
+                               0._wp, sin(p%rotate(1)), cos(p%rotate(1)), 0._wp, &
+                               0._wp, 0._wp, 0._wp, 1._wp], shape(rx)))
 
         ry = transpose(reshape([ &
-                               cos(p%rotate(2)), 0d0, sin(p%rotate(2)), 0d0, &
-                               0d0, 1d0, 0d0, 0d0, &
-                               -sin(p%rotate(2)), 0d0, cos(p%rotate(2)), 0d0, &
-                               0d0, 0d0, 0d0, 1d0], shape(ry)))
+                               cos(p%rotate(2)), 0._wp, sin(p%rotate(2)), 0._wp, &
+                               0._wp, 1._wp, 0._wp, 0._wp, &
+                               -sin(p%rotate(2)), 0._wp, cos(p%rotate(2)), 0._wp, &
+                               0._wp, 0._wp, 0._wp, 1._wp], shape(ry)))
 
         tr = transpose(reshape([ &
-                               1d0, 0d0, 0d0, p%translate(1), &
-                               0d0, 1d0, 0d0, p%translate(2), &
-                               0d0, 0d0, 1d0, p%translate(3), &
-                               0d0, 0d0, 0d0, 1d0], shape(tr)))
+                               1._wp, 0._wp, 0._wp, p%translate(1), &
+                               0._wp, 1._wp, 0._wp, p%translate(2), &
+                               0._wp, 0._wp, 1._wp, p%translate(3), &
+                               0._wp, 0._wp, 0._wp, 1._wp], shape(tr)))
 
         out_matrix = matmul(tr, matmul(ry, matmul(rx, matmul(rz, sc))))
 
@@ -377,9 +361,9 @@ contains
         t_vec3, intent(inout) :: vec
         t_mat4x4, intent(in) :: matrix
 
-        real(kind(0d0)), dimension(1:4) :: tmp
+        real(wp), dimension(1:4) :: tmp
 
-        tmp = matmul(matrix, [vec(1), vec(2), vec(3), 1d0])
+        tmp = matmul(matrix, [vec(1), vec(2), vec(3), 1._wp])
         vec = tmp(1:3)
 
     end subroutine s_transform_vec
@@ -394,7 +378,7 @@ contains
 
         integer :: i
 
-        real(kind(0d0)), dimension(1:4) :: tmp
+        real(wp), dimension(1:4) :: tmp
 
         do i = 1, 3
             call s_transform_vec(triangle%v(i, :), matrix)
@@ -429,8 +413,8 @@ contains
         integer :: i, j
 
         if (size(model%trs) == 0) then
-            bbox%min = 0d0
-            bbox%max = 0d0
+            bbox%min = 0._wp
+            bbox%max = 0._wp
             return
         end if
 
diff --git a/src/common/m_helper_basic.f90 b/src/common/m_helper_basic.f90
index 0611ff86f..cd1915657 100644
--- a/src/common/m_helper_basic.f90
+++ b/src/common/m_helper_basic.f90
@@ -19,47 +19,45 @@ module m_helper_basic
 
 contains
 
-    !> This procedure checks if two floating point numbers of kind(0d0) are within tolerance.
+    !> This procedure checks if two floating point numbers of wp are within tolerance.
     !! @param a First number.
     !! @param b Second number.
-    !! @param tol_input Relative error (default = 1d-6).
+    !! @param tol_input Relative error (default = 1e-6_wp).
     !! @return Result of the comparison.
     logical function f_approx_equal(a, b, tol_input) result(res)
         !$acc routine seq
-        ! Reference: https://floating-point-gui.de/errors/comparison/
-
-        real(kind(0d0)), intent(in) :: a, b
-        real(kind(0d0)), optional, intent(in) :: tol_input
-        real(kind(0d0)) :: tol
+        real(wp), intent(in) :: a, b
+        real(wp), optional, intent(in) :: tol_input
+        real(wp) :: tol
 
         if (present(tol_input)) then
             tol = tol_input
         else
-            tol = 1d-6
+            tol = 1e-6_wp
         end if
 
         if (a == b) then
             res = .true.
-        else if (a == 0d0 .or. b == 0d0 .or. (abs(a) + abs(b) < tiny(a))) then
+        else if (a == 0._wp .or. b == 0._wp .or. (abs(a) + abs(b) < tiny(a))) then
             res = (abs(a - b) < (tol*tiny(a)))
         else
             res = (abs(a - b)/min(abs(a) + abs(b), huge(a)) < tol)
         end if
     end function f_approx_equal
 
-    !> Checks if a real(kind(0d0)) variable is of default value.
+    !> Checks if a real(wp) variable is of default value.
     !! @param var Variable to check.
     logical function f_is_default(var) result(res)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: var
+        real(wp), intent(in) :: var
 
         res = f_approx_equal(var, dflt_real)
     end function f_is_default
 
-    !> Checks if ALL elements of a real(kind(0d0)) array are of default value.
+    !> Checks if ALL elements of a real(wp) array are of default value.
     !! @param var_array Array to check.
     logical function f_all_default(var_array) result(res)
-        real(kind(0d0)), intent(in) :: var_array(:)
+        real(wp), intent(in) :: var_array(:)
         logical :: res_array(size(var_array))
         integer :: i
 
@@ -70,13 +68,13 @@ logical function f_all_default(var_array) result(res)
         res = all(res_array)
     end function f_all_default
 
-    !> Checks if a real(kind(0d0)) variable is an integer.
+    !> Checks if a real(wp) variable is an integer.
     !! @param var Variable to check.
     logical function f_is_integer(var) result(res)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: var
+        real(wp), intent(in) :: var
 
-        res = f_approx_equal(var, real(nint(var), kind(0d0)))
+        res = f_approx_equal(var, real(nint(var), wp))
     end function f_is_integer
 
 end module m_helper_basic
diff --git a/src/common/m_mpi_common.fpp b/src/common/m_mpi_common.fpp
index 403ac4f13..8870271c5 100644
--- a/src/common/m_mpi_common.fpp
+++ b/src/common/m_mpi_common.fpp
@@ -128,7 +128,7 @@ contains
         ! Define the view for each variable
         do i = 1, sys_size
             call MPI_TYPE_CREATE_SUBARRAY(num_dims, sizes_glb, sizes_loc, start_idx, &
-                                          MPI_ORDER_FORTRAN, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), ierr)
+                                          MPI_ORDER_FORTRAN, mpi_p, MPI_IO_DATA%view(i), ierr)
             call MPI_TYPE_COMMIT(MPI_IO_DATA%view(i), ierr)
         end do
 
@@ -136,7 +136,7 @@ contains
         if (qbmm .and. .not. polytropic) then
             do i = sys_size + 1, sys_size + 2*nb*4
                 call MPI_TYPE_CREATE_SUBARRAY(num_dims, sizes_glb, sizes_loc, start_idx, &
-                                              MPI_ORDER_FORTRAN, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), ierr)
+                                              MPI_ORDER_FORTRAN, mpi_p, MPI_IO_DATA%view(i), ierr)
                 call MPI_TYPE_COMMIT(MPI_IO_DATA%view(i), ierr)
 
             end do
@@ -164,9 +164,9 @@ contains
 
 #ifndef MFC_POST_PROCESS
             call MPI_TYPE_CREATE_SUBARRAY(num_dims, sizes_glb, sizes_loc, start_idx, &
-                                          MPI_ORDER_FORTRAN, MPI_DOUBLE_PRECISION, MPI_IO_levelset_DATA%view, ierr)
+                                          MPI_ORDER_FORTRAN, mpi_p, MPI_IO_levelset_DATA%view, ierr)
             call MPI_TYPE_CREATE_SUBARRAY(num_dims, sizes_glb, sizes_loc, start_idx, &
-                                          MPI_ORDER_FORTRAN, MPI_DOUBLE_PRECISION, MPI_IO_levelsetnorm_DATA%view, ierr)
+                                          MPI_ORDER_FORTRAN, mpi_p, MPI_IO_levelsetnorm_DATA%view, ierr)
 
             call MPI_TYPE_COMMIT(MPI_IO_levelset_DATA%view, ierr)
             call MPI_TYPE_COMMIT(MPI_IO_levelsetnorm_DATA%view, ierr)
@@ -194,7 +194,7 @@ contains
 #endif
 
                     call MPI_TYPE_CREATE_SUBARRAY(1, airfoil_glb, airfoil_loc, airfoil_start, &
-                                                  MPI_ORDER_FORTRAN, MPI_DOUBLE_PRECISION, MPI_IO_airfoil_IB_DATA%view(1), ierr)
+                                                  MPI_ORDER_FORTRAN, mpi_p, MPI_IO_airfoil_IB_DATA%view(1), ierr)
                     call MPI_TYPE_COMMIT(MPI_IO_airfoil_IB_DATA%view(1), ierr)
 
 #ifdef MFC_PRE_PROCESS
@@ -204,7 +204,7 @@ contains
                     end do
 #endif
                     call MPI_TYPE_CREATE_SUBARRAY(1, airfoil_glb, airfoil_loc, airfoil_start, &
-                                                  MPI_ORDER_FORTRAN, MPI_DOUBLE_PRECISION, MPI_IO_airfoil_IB_DATA%view(2), ierr)
+                                                  MPI_ORDER_FORTRAN, mpi_p, MPI_IO_airfoil_IB_DATA%view(2), ierr)
                     call MPI_TYPE_COMMIT(MPI_IO_airfoil_IB_DATA%view(2), ierr)
 
                 end if
@@ -219,12 +219,12 @@ contains
 
     subroutine mpi_bcast_time_step_values(proc_time, time_avg)
 
-        real(kind(0d0)), dimension(0:num_procs - 1), intent(inout) :: proc_time
-        real(kind(0d0)), intent(inout) :: time_avg
+        real(wp), dimension(0:num_procs - 1), intent(inout) :: proc_time
+        real(wp), intent(inout) :: time_avg
 
 #ifdef MFC_MPI
 
-        call MPI_GATHER(time_avg, 1, MPI_DOUBLE_PRECISION, proc_time(0), 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+        call MPI_GATHER(time_avg, 1, mpi_p, proc_time(0), 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
 
 #endif
 
@@ -253,15 +253,15 @@ contains
                                                        ccfl_max_glb, &
                                                        Rc_min_glb)
 
-        real(kind(0d0)), intent(in) :: icfl_max_loc
-        real(kind(0d0)), intent(in) :: vcfl_max_loc
-        real(kind(0d0)), intent(in) :: ccfl_max_loc
-        real(kind(0d0)), intent(in) :: Rc_min_loc
+        real(wp), intent(in) :: icfl_max_loc
+        real(wp), intent(in) :: vcfl_max_loc
+        real(wp), intent(in) :: ccfl_max_loc
+        real(wp), intent(in) :: Rc_min_loc
 
-        real(kind(0d0)), intent(out) :: icfl_max_glb
-        real(kind(0d0)), intent(out) :: vcfl_max_glb
-        real(kind(0d0)), intent(out) :: ccfl_max_glb
-        real(kind(0d0)), intent(out) :: Rc_min_glb
+        real(wp), intent(out) :: icfl_max_glb
+        real(wp), intent(out) :: vcfl_max_glb
+        real(wp), intent(out) :: ccfl_max_glb
+        real(wp), intent(out) :: Rc_min_glb
 
 #ifdef MFC_SIMULATION
 #ifdef MFC_MPI
@@ -269,15 +269,15 @@ contains
         ! Reducing local extrema of ICFL, VCFL, CCFL and Rc numbers to their
         ! global extrema and bookkeeping the results on the rank 0 processor
         call MPI_REDUCE(icfl_max_loc, icfl_max_glb, 1, &
-                        MPI_DOUBLE_PRECISION, MPI_MAX, 0, &
+                        mpi_p, MPI_MAX, 0, &
                         MPI_COMM_WORLD, ierr)
 
         if (viscous) then
             call MPI_REDUCE(vcfl_max_loc, vcfl_max_glb, 1, &
-                            MPI_DOUBLE_PRECISION, MPI_MAX, 0, &
+                            mpi_p, MPI_MAX, 0, &
                             MPI_COMM_WORLD, ierr)
             call MPI_REDUCE(Rc_min_loc, Rc_min_glb, 1, &
-                            MPI_DOUBLE_PRECISION, MPI_MIN, 0, &
+                            mpi_p, MPI_MIN, 0, &
                             MPI_COMM_WORLD, ierr)
         end if
 
@@ -304,13 +304,13 @@ contains
         !!  @param var_glb The globally reduced value
     subroutine s_mpi_allreduce_sum(var_loc, var_glb)
 
-        real(kind(0d0)), intent(in) :: var_loc
-        real(kind(0d0)), intent(out) :: var_glb
+        real(wp), intent(in) :: var_loc
+        real(wp), intent(out) :: var_glb
 
 #ifdef MFC_MPI
 
         ! Performing the reduction procedure
-        call MPI_ALLREDUCE(var_loc, var_glb, 1, MPI_DOUBLE_PRECISION, &
+        call MPI_ALLREDUCE(var_loc, var_glb, 1, mpi_p, &
                            MPI_SUM, MPI_COMM_WORLD, ierr)
 
 #endif
@@ -326,13 +326,13 @@ contains
         !!  @param var_glb The globally reduced value
     subroutine s_mpi_allreduce_min(var_loc, var_glb)
 
-        real(kind(0d0)), intent(in) :: var_loc
-        real(kind(0d0)), intent(out) :: var_glb
+        real(wp), intent(in) :: var_loc
+        real(wp), intent(out) :: var_glb
 
 #ifdef MFC_MPI
 
         ! Performing the reduction procedure
-        call MPI_ALLREDUCE(var_loc, var_glb, 1, MPI_DOUBLE_PRECISION, &
+        call MPI_ALLREDUCE(var_loc, var_glb, 1, mpi_p, &
                            MPI_MIN, MPI_COMM_WORLD, ierr)
 
 #endif
@@ -348,13 +348,13 @@ contains
         !!  @param var_glb The globally reduced value
     subroutine s_mpi_allreduce_max(var_loc, var_glb)
 
-        real(kind(0d0)), intent(in) :: var_loc
-        real(kind(0d0)), intent(out) :: var_glb
+        real(wp), intent(in) :: var_loc
+        real(wp), intent(out) :: var_glb
 
 #ifdef MFC_MPI
 
         ! Performing the reduction procedure
-        call MPI_ALLREDUCE(var_loc, var_glb, 1, MPI_DOUBLE_PRECISION, &
+        call MPI_ALLREDUCE(var_loc, var_glb, 1, mpi_p, &
                            MPI_MAX, MPI_COMM_WORLD, ierr)
 
 #endif
@@ -369,19 +369,19 @@ contains
         !!      the minimum value, reduced amongst all of the local values.
     subroutine s_mpi_reduce_min(var_loc)
 
-        real(kind(0d0)), intent(inout) :: var_loc
+        real(wp), intent(inout) :: var_loc
 
 #ifdef MFC_MPI
 
         ! Temporary storage variable that holds the reduced minimum value
-        real(kind(0d0)) :: var_glb
+        real(wp) :: var_glb
 
         ! Performing reduction procedure and eventually storing its result
         ! into the variable that was initially inputted into the subroutine
-        call MPI_REDUCE(var_loc, var_glb, 1, MPI_DOUBLE_PRECISION, &
+        call MPI_REDUCE(var_loc, var_glb, 1, mpi_p, &
                         MPI_MIN, 0, MPI_COMM_WORLD, ierr)
 
-        call MPI_BCAST(var_glb, 1, MPI_DOUBLE_PRECISION, &
+        call MPI_BCAST(var_glb, 1, mpi_p, &
                        0, MPI_COMM_WORLD, ierr)
 
         var_loc = var_glb
@@ -404,20 +404,20 @@ contains
         !!  belongs.
     subroutine s_mpi_reduce_maxloc(var_loc)
 
-        real(kind(0d0)), dimension(2), intent(inout) :: var_loc
+        real(wp), dimension(2), intent(inout) :: var_loc
 
 #ifdef MFC_MPI
 
-        real(kind(0d0)), dimension(2) :: var_glb  !<
+        real(wp), dimension(2) :: var_glb  !<
             !! Temporary storage variable that holds the reduced maximum value
             !! and the rank of the processor with which the value is associated
 
         ! Performing reduction procedure and eventually storing its result
         ! into the variable that was initially inputted into the subroutine
-        call MPI_REDUCE(var_loc, var_glb, 1, MPI_2DOUBLE_PRECISION, &
+        call MPI_REDUCE(var_loc, var_glb, 1, mpi_2p, &
                         MPI_MAXLOC, 0, MPI_COMM_WORLD, ierr)
 
-        call MPI_BCAST(var_glb, 1, MPI_2DOUBLE_PRECISION, &
+        call MPI_BCAST(var_glb, 1, mpi_2p, &
                        0, MPI_COMM_WORLD, ierr)
 
         var_loc = var_glb
diff --git a/src/common/m_phase_change.fpp b/src/common/m_phase_change.fpp
index d523d4706..132651e68 100644
--- a/src/common/m_phase_change.fpp
+++ b/src/common/m_phase_change.fpp
@@ -36,17 +36,17 @@ module m_phase_change
 
     !> @name Parameters for the first order transition phase change
     !> @{
-    integer, parameter :: max_iter = 1e8        !< max # of iterations
-    real(kind(0d0)), parameter :: pCr = 4.94d7   !< Critical water pressure
-    real(kind(0d0)), parameter :: TCr = 385.05 + 273.15  !< Critical water temperature
-    real(kind(0d0)), parameter :: mixM = 1.0d-8 !< threshold for 'mixture cell'. If Y < mixM, phase change does not happen
+    integer, parameter :: max_iter = 1e8_wp        !< max # of iterations
+    real(wp), parameter :: pCr = 4.94e7_wp   !< Critical water pressure
+    real(wp), parameter :: TCr = 385.05_wp + 273.15_wp  !< Critical water temperature
+    real(wp), parameter :: mixM = 1.0e-8_wp !< threshold for 'mixture cell'. If Y < mixM, phase change does not happen
     integer, parameter :: lp = 1    !< index for the liquid phase of the reacting fluid
     integer, parameter :: vp = 2    !< index for the vapor phase of the reacting fluid
     !> @}
 
     !> @name Gibbs free energy phase change parameters
     !> @{
-    real(kind(0d0)) :: A, B, C, D
+    real(wp) :: A, B, C, D
     !> @}
 
     !$acc declare create(max_iter,pCr,TCr,mixM,lp,vp,A,B,C,D)
@@ -70,15 +70,15 @@ contains
     subroutine s_initialize_phasechange_module
         ! variables used in the calculation of the saturation curves for fluids 1 and 2
         A = (gs_min(lp)*cvs(lp) - gs_min(vp)*cvs(vp) &
-             + qvps(vp) - qvps(lp))/((gs_min(vp) - 1.0d0)*cvs(vp))
+             + qvps(vp) - qvps(lp))/((gs_min(vp) - 1.0_wp)*cvs(vp))
 
-        B = (qvs(lp) - qvs(vp))/((gs_min(vp) - 1.0d0)*cvs(vp))
+        B = (qvs(lp) - qvs(vp))/((gs_min(vp) - 1.0_wp)*cvs(vp))
 
         C = (gs_min(vp)*cvs(vp) - gs_min(lp)*cvs(lp)) &
-            /((gs_min(vp) - 1.0d0)*cvs(vp))
+            /((gs_min(vp) - 1.0_wp)*cvs(vp))
 
-        D = ((gs_min(lp) - 1.0d0)*cvs(lp)) &
-            /((gs_min(vp) - 1.0d0)*cvs(vp))
+        D = ((gs_min(lp) - 1.0_wp)*cvs(lp)) &
+            /((gs_min(vp) - 1.0_wp)*cvs(vp))
 
     end subroutine s_initialize_phasechange_module
 
@@ -90,15 +90,15 @@ contains
     subroutine s_infinite_relaxation_k(q_cons_vf)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_cons_vf
-        real(kind(0.0d0)) :: pS, pSOV, pSSL !< equilibrium pressure for mixture, overheated vapor, and subcooled liquid
-        real(kind(0.0d0)) :: TS, TSOV, TSSL, TSatOV, TSatSL !< equilibrium temperature for mixture, overheated vapor, and subcooled liquid. Saturation Temperatures at overheated vapor and subcooled liquid
-        real(kind(0.0d0)) :: rhoe, dynE, rhos !< total internal energy, kinetic energy, and total entropy
-        real(kind(0.0d0)) :: rho, rM, m1, m2, MCT !< total density, total reacting mass, individual reacting masses
-        real(kind(0.0d0)) :: TvF !< total volume fraction
+        real(kind(0.0_wp)) :: pS, pSOV, pSSL !< equilibrium pressure for mixture, overheated vapor, and subcooled liquid
+        real(kind(0.0_wp)) :: TS, TSOV, TSSL, TSatOV, TSatSL !< equilibrium temperature for mixture, overheated vapor, and subcooled liquid. Saturation Temperatures at overheated vapor and subcooled liquid
+        real(kind(0.0_wp)) :: rhoe, dynE, rhos !< total internal energy, kinetic energy, and total entropy
+        real(kind(0.0_wp)) :: rho, rM, m1, m2, MCT !< total density, total reacting mass, individual reacting masses
+        real(kind(0.0_wp)) :: TvF !< total volume fraction
 
         !$acc declare create(pS, pSOV, pSSL, TS, TSOV, TSatOV, TSatSL, TSSL, rhoe, dynE, rhos, rho, rM, m1, m2, MCT, TvF)
 
-        real(kind(0d0)), dimension(num_fluids) :: p_infOV, p_infpT, p_infSL, sk, hk, gk, ek, rhok
+        real(wp), dimension(num_fluids) :: p_infOV, p_infpT, p_infSL, sk, hk, gk, ek, rhok
 
         !< Generic loop iterators
         integer :: i, j, k, l
@@ -111,7 +111,7 @@ contains
             do k = 0, n
                 do l = 0, p
 
-                    rho = 0.0d0; TvF = 0.0d0
+                    rho = 0.0_wp; TvF = 0.0_wp
                     !$acc loop seq
                     do i = 1, num_fluids
 
@@ -137,11 +137,11 @@ contains
                     m2 = q_cons_vf(vp + contxb - 1)%sf(j, k, l)
 
                     ! kinetic energy as an auxiliary variable to the calculation of the total internal energy
-                    dynE = 0.0d0
+                    dynE = 0.0_wp
                     !$acc loop seq
                     do i = momxb, momxe
 
-                        dynE = dynE + 5.0d-1*q_cons_vf(i)%sf(j, k, l)**2/rho
+                        dynE = dynE + 5.0e-1_wp*q_cons_vf(i)%sf(j, k, l)**2/rho
 
                     end do
 
@@ -170,7 +170,7 @@ contains
                         q_cons_vf(lp + contxb - 1)%sf(j, k, l) = mixM*rM
 
                         ! tranferring the total mass to vapor
-                        q_cons_vf(vp + contxb - 1)%sf(j, k, l) = (1.0d0 - mixM)*rM
+                        q_cons_vf(vp + contxb - 1)%sf(j, k, l) = (1.0_wp - mixM)*rM
 
                         ! calling pT-equilibrium for overheated vapor, which is MFL = 0
                         call s_infinite_pt_relaxation_k(j, k, l, 0, pSOV, p_infOV, rM, q_cons_vf, rhoe, TSOV)
@@ -180,7 +180,7 @@ contains
 
                         ! subcooled liquid case
                         ! tranferring the total mass to liquid
-                        q_cons_vf(lp + contxb - 1)%sf(j, k, l) = (1.0d0 - mixM)*rM
+                        q_cons_vf(lp + contxb - 1)%sf(j, k, l) = (1.0_wp - mixM)*rM
 
                         ! depleting the mass of vapor
                         q_cons_vf(vp + contxb - 1)%sf(j, k, l) = mixM*rM
@@ -204,7 +204,7 @@ contains
                             q_cons_vf(lp + contxb - 1)%sf(j, k, l) = mixM*rM
 
                             ! correcting the vapor partial density
-                            q_cons_vf(vp + contxb - 1)%sf(j, k, l) = (1.0d0 - mixM)*rM
+                            q_cons_vf(vp + contxb - 1)%sf(j, k, l) = (1.0_wp - mixM)*rM
 
                         elseif (TSSL < TSatSL) then
 
@@ -215,7 +215,7 @@ contains
                             TS = TSSL
 
                             ! correcting the liquid partial density
-                            q_cons_vf(lp + contxb - 1)%sf(j, k, l) = (1.0d0 - mixM)*rM
+                            q_cons_vf(lp + contxb - 1)%sf(j, k, l) = (1.0_wp - mixM)*rM
 
                             ! correcting the vapor partial density
                             q_cons_vf(vp + contxb - 1)%sf(j, k, l) = mixM*rM
@@ -239,8 +239,8 @@ contains
                     ! Calculations AFTER equilibrium
 
                     ! entropy
-                    sk(1:num_fluids) = cvs(1:num_fluids)*DLOG((TS**gs_min(1:num_fluids)) &
-                                                              /((pS + ps_inf(1:num_fluids))**(gs_min(1:num_fluids) - 1.0d0))) + qvps(1:num_fluids)
+                    sk(1:num_fluids) = cvs(1:num_fluids)*log((TS**gs_min(1:num_fluids)) &
+                                                             /((pS + ps_inf(1:num_fluids))**(gs_min(1:num_fluids) - 1.0_wp))) + qvps(1:num_fluids)
 
                     ! enthalpy
                     hk(1:num_fluids) = gs_min(1:num_fluids)*cvs(1:num_fluids)*TS &
@@ -259,7 +259,7 @@ contains
                                        *cvs(1:num_fluids)*TS + qvs(1:num_fluids)
 
                     ! calculating volume fractions, internal energies, and total entropy
-                    rhos = 0.0d0
+                    rhos = 0.0_wp
                     !$acc loop seq
                     do i = 1, num_fluids
 
@@ -300,19 +300,18 @@ contains
 
         ! initializing variables
         integer, intent(in) :: j, k, l, MFL
-        real(kind(0.0d0)), intent(out) :: pS
-        real(kind(0.0d0)), dimension(num_fluids), intent(out) :: p_infpT
-        real(kind(0.0d0)), intent(in) :: rM
+        real(kind(0.0_wp)), intent(out) :: pS
+        real(kind(0.0_wp)), dimension(num_fluids), intent(out) :: p_infpT
+        real(kind(0.0_wp)), intent(in) :: rM
         type(scalar_field), dimension(sys_size), intent(in) :: q_cons_vf
-        real(kind(0.0d0)), intent(in) :: rhoe
-        real(kind(0.0d0)), intent(out) :: TS
-
-        real(kind(0.0d0)) :: gp, gpp, hp, pO, mCP, mQ !< variables for the Newton Solver
+        real(kind(0.0_wp)), intent(in) :: rhoe
+        real(kind(0.0_wp)), intent(out) :: TS
+        real(kind(0.0_wp)) :: gp, gpp, hp, pO, mCP, mQ !< variables for the Newton Solver
 
         integer :: i, ns !< generic loop iterators
 
         ! auxiliary variables for the pT-equilibrium solver
-        mCP = 0.0d0; mQ = 0.0d0; p_infpT = ps_inf; 
+        mCP = 0.0_wp; mQ = 0.0_wp; p_infpT = ps_inf; 
         ! Performing tests before initializing the pT-equilibrium
         !$acc loop seq
         do i = 1, num_fluids
@@ -326,16 +325,16 @@ contains
         end do
 
         ! Checking energy constraint
-        if ((rhoe - mQ - minval(p_infpT)) < 0.0d0) then
+        if ((rhoe - mQ - minval(p_infpT)) < 0.0_wp) then
 
             if ((MFL == 0) .or. (MFL == 1)) then
 
                 ! Assigning zero values for mass depletion cases
                 ! pressure
-                pS = 0.0d0
+                pS = 0.0_wp
 
                 ! temperature
-                TS = 0.0d0
+                TS = 0.0_wp
 
                 return
             end if
@@ -344,16 +343,16 @@ contains
 
         ! calculating initial estimate for pressure in the pT-relaxation procedure. I will also use this variable to
         ! iterate over the Newton's solver
-        pO = 0.0d0
+        pO = 0.0_wp
 
         ! Maybe improve this condition afterwards. As long as the initial guess is in between -min(ps_inf)
         ! and infinity, a solution should be able to be found.
-        pS = 1.0d4
+        pS = 1.0e4_wp
 
         ! Newton Solver for the pT-equilibrium
         ns = 0
-        ! change this relative error metric. 1E4 is just arbitrary
-        do while ((DABS(pS - pO) > palpha_eps) .and. (DABS((pS - pO)/pO) > palpha_eps/1e4) .or. (ns == 0))
+        ! change this relative error metric. 1e4_wp is just arbitrary
+        do while ((abs(pS - pO) > palpha_eps) .and. (abs((pS - pO)/pO) > palpha_eps/1e4_wp) .or. (ns == 0))
 
             ! increasing counter
             ns = ns + 1
@@ -362,23 +361,23 @@ contains
             pO = pS
 
             ! updating functions used in the Newton's solver
-            gpp = 0.0d0; gp = 0.0d0; hp = 0.0d0
+            gpp = 0.0_wp; gp = 0.0_wp; hp = 0.0_wp
             !$acc loop seq
             do i = 1, num_fluids
 
-                gp = gp + (gs_min(i) - 1.0d0)*q_cons_vf(i + contxb - 1)%sf(j, k, l)*cvs(i) &
+                gp = gp + (gs_min(i) - 1.0_wp)*q_cons_vf(i + contxb - 1)%sf(j, k, l)*cvs(i) &
                      *(rhoe + pS - mQ)/(mCP*(pS + p_infpT(i)))
 
-                gpp = gpp + (gs_min(i) - 1.0d0)*q_cons_vf(i + contxb - 1)%sf(j, k, l)*cvs(i) &
+                gpp = gpp + (gs_min(i) - 1.0_wp)*q_cons_vf(i + contxb - 1)%sf(j, k, l)*cvs(i) &
                       *(p_infpT(i) - rhoe + mQ)/(mCP*(pS + p_infpT(i))**2)
 
             end do
 
-            hp = 1.0d0/(rhoe + pS - mQ) + 1.0d0/(pS + minval(p_infpT))
+            hp = 1.0_wp/(rhoe + pS - mQ) + 1.0_wp/(pS + minval(p_infpT))
 
             ! updating common pressure for the newton solver
-            pS = pO + ((1.0d0 - gp)/gpp)/(1.0d0 - (1.0d0 - gp + DABS(1.0d0 - gp)) &
-                                          /(2.0d0*gpp)*hp)
+            pS = pO + ((1.0_wp - gp)/gpp)/(1.0_wp - (1.0_wp - gp + abs(1.0_wp - gp)) &
+                                           /(2.0_wp*gpp)*hp)
         end do
 
         ! common temperature
@@ -405,17 +404,17 @@ contains
 #endif
 
         integer, intent(in) :: j, k, l
-        real(kind(0.0d0)), intent(inout) :: pS
-        real(kind(0.0d0)), dimension(num_fluids), intent(in) :: p_infpT
-        real(kind(0.0d0)), intent(in) :: rhoe
+        real(kind(0.0_wp)), intent(inout) :: pS
+        real(kind(0.0_wp)), dimension(num_fluids), intent(in) :: p_infpT
+        real(kind(0.0_wp)), intent(in) :: rhoe
         type(scalar_field), dimension(sys_size), intent(inout) :: q_cons_vf
-        real(kind(0.0d0)), intent(inout) :: TS
+        real(kind(0.0_wp)), intent(inout) :: TS
 
-        real(kind(0.0d0)), dimension(num_fluids) :: p_infpTg !< stiffness for the participating fluids for pTg-equilibrium
-        real(kind(0.0d0)), dimension(2, 2) :: Jac, InvJac, TJac !< matrices for the Newton Solver
-        real(kind(0.0d0)), dimension(2) :: R2D, DeltamP !< residual and correction array
-        real(kind(0.0d0)) :: Om ! underrelaxation factor
-        real(kind(0.0d0)) :: mCP, mCPD, mCVGP, mCVGP2, mQ, mQD ! auxiliary variables for the pTg-solver
+        real(kind(0.0_wp)), dimension(num_fluids) :: p_infpTg !< stiffness for the participating fluids for pTg-equilibrium
+        real(kind(0.0_wp)), dimension(2, 2) :: Jac, InvJac, TJac !< matrices for the Newton Solver
+        real(kind(0.0_wp)), dimension(2) :: R2D, DeltamP !< residual and correction array
+        real(kind(0.0_wp)) :: Om ! underrelaxation factor
+        real(kind(0.0_wp)) :: mCP, mCPD, mCVGP, mCVGP2, mQ, mQD ! auxiliary variables for the pTg-solver
 
         !< Generic loop iterators
         integer :: i, ns
@@ -425,17 +424,17 @@ contains
         ns = 0
 
         ! Relaxation factor
-        Om = 1.0d-3
+        Om = 1.0e-3_wp
 
         p_infpTg = p_infpT
 
-        if (((pS < 0.0d0) .and. ((q_cons_vf(lp + contxb - 1)%sf(j, k, l) &
-                                  + q_cons_vf(vp + contxb - 1)%sf(j, k, l)) > ((rhoe &
-                                                                                - gs_min(lp)*ps_inf(lp)/(gs_min(lp) - 1))/qvs(lp)))) .or. &
-            ((pS >= 0.0d0) .and. (pS < 1.0d-1))) then
+        if (((pS < 0.0_wp) .and. ((q_cons_vf(lp + contxb - 1)%sf(j, k, l) &
+                                   + q_cons_vf(vp + contxb - 1)%sf(j, k, l)) > ((rhoe &
+                                                                                 - gs_min(lp)*ps_inf(lp)/(gs_min(lp) - 1))/qvs(lp)))) .or. &
+            ((pS >= 0.0_wp) .and. (pS < 1.0e-1_wp))) then
 
             ! improve this initial condition
-            pS = 1.0d4
+            pS = 1.0e4_wp
 
         end if
 
@@ -444,17 +443,17 @@ contains
         ! for the residual, and how to do it adequately.
         ! Dummy guess to start the pTg-equilibrium problem.
         ! improve this initial condition
-        R2D(1) = 0.0d0; R2D(2) = 0.0d0
-        DeltamP(1) = 0.0d0; DeltamP(2) = 0.0d0
-        do while (((DSQRT(R2D(1)**2 + R2D(2)**2) > ptgalpha_eps) &
-                   .and. ((DSQRT(R2D(1)**2 + R2D(2)**2)/rhoe) > (ptgalpha_eps/1d6))) &
+        R2D(1) = 0.0_wp; R2D(2) = 0.0_wp
+        DeltamP(1) = 0.0_wp; DeltamP(2) = 0.0_wp
+        do while (((sqrt(R2D(1)**2 + R2D(2)**2) > ptgalpha_eps) &
+                   .and. ((sqrt(R2D(1)**2 + R2D(2)**2)/rhoe) > (ptgalpha_eps/1e6_wp))) &
                   .or. (ns == 0))
 
             ! Updating counter for the iterative procedure
             ns = ns + 1
 
             ! Auxiliary variables to help in the calculation of the residue
-            mCP = 0.0d0; mCPD = 0.0d0; mCVGP = 0.0d0; mCVGP2 = 0.0d0; mQ = 0.0d0; mQD = 0.0d0
+            mCP = 0.0_wp; mCPD = 0.0_wp; mCVGP = 0.0_wp; mCVGP2 = 0.0_wp; mQ = 0.0_wp; mQD = 0.0_wp
             ! Those must be updated through the iterations, as they either depend on
             ! the partial masses for all fluids, or on the equilibrium pressure
             !$acc loop seq
@@ -491,7 +490,7 @@ contains
             call s_compute_jacobian_matrix(InvJac, j, Jac, k, l, mCPD, mCVGP, mCVGP2, pS, q_cons_vf, TJac)
 
             ! calculating correction array for Newton's method
-            DeltamP = -1.0d0*matmul(InvJac, R2D)
+            DeltamP = -1.0_wp*matmul(InvJac, R2D)
 
             ! updating two reacting 'masses'. Recall that inert 'masses' do not change during the phase change
             ! liquid
@@ -531,19 +530,19 @@ contains
 
         !> @name variables for the correction of the reacting partial densities
         !> @{
-        real(kind(0.0d0)), intent(out) :: MCT
+        real(kind(0.0_wp)), intent(out) :: MCT
         type(scalar_field), dimension(sys_size), intent(inout) :: q_cons_vf
-        real(kind(0.0d0)), intent(inout) :: rM
+        real(kind(0.0_wp)), intent(inout) :: rM
         integer, intent(in) :: j, k, l
         !> @}
-        if (rM < 0.0d0) then
+        if (rM < 0.0_wp) then
 
-            if ((q_cons_vf(lp + contxb - 1)%sf(j, k, l) >= -1.0d0*mixM) .and. &
-                (q_cons_vf(vp + contxb - 1)%sf(j, k, l) >= -1.0d0*mixM)) then
+            if ((q_cons_vf(lp + contxb - 1)%sf(j, k, l) >= -1.0_wp*mixM) .and. &
+                (q_cons_vf(vp + contxb - 1)%sf(j, k, l) >= -1.0_wp*mixM)) then
 
-                q_cons_vf(lp + contxb - 1)%sf(j, k, l) = 0.0d0
+                q_cons_vf(lp + contxb - 1)%sf(j, k, l) = 0.0_wp
 
-                q_cons_vf(vp + contxb - 1)%sf(j, k, l) = 0.0d0
+                q_cons_vf(vp + contxb - 1)%sf(j, k, l) = 0.0_wp
 
                 rM = q_cons_vf(lp + contxb - 1)%sf(j, k, l) + q_cons_vf(vp + contxb - 1)%sf(j, k, l)
 
@@ -556,15 +555,15 @@ contains
         MCT = 2*mixM
 
         ! correcting the partial densities of the reacting fluids. What to do for the nonreacting ones?
-        if (q_cons_vf(lp + contxb - 1)%sf(j, k, l) < 0.0d0) then
+        if (q_cons_vf(lp + contxb - 1)%sf(j, k, l) < 0.0_wp) then
 
             q_cons_vf(lp + contxb - 1)%sf(j, k, l) = MCT*rM
 
-            q_cons_vf(vp + contxb - 1)%sf(j, k, l) = (1.0d0 - MCT)*rM
+            q_cons_vf(vp + contxb - 1)%sf(j, k, l) = (1.0_wp - MCT)*rM
 
-        elseif (q_cons_vf(vp + contxb - 1)%sf(j, k, l) < 0.0d0) then
+        elseif (q_cons_vf(vp + contxb - 1)%sf(j, k, l) < 0.0_wp) then
 
-            q_cons_vf(lp + contxb - 1)%sf(j, k, l) = (1.0d0 - MCT)*rM
+            q_cons_vf(lp + contxb - 1)%sf(j, k, l) = (1.0_wp - MCT)*rM
 
             q_cons_vf(vp + contxb - 1)%sf(j, k, l) = MCT*rM
 
@@ -592,15 +591,15 @@ contains
         !$acc routine seq
 #endif
 
-        real(kind(0.0d0)), dimension(2, 2), intent(out) :: InvJac
+        real(kind(0.0_wp)), dimension(2, 2), intent(out) :: InvJac
         integer, intent(in) :: j
-        real(kind(0.0d0)), dimension(2, 2), intent(out) :: Jac
+        real(kind(0.0_wp)), dimension(2, 2), intent(out) :: Jac
         integer, intent(in) :: k, l
-        real(kind(0.0d0)), intent(in) :: mCPD, mCVGP, mCVGP2, pS
+        real(kind(0.0_wp)), intent(in) :: mCPD, mCVGP, mCVGP2, pS
         type(scalar_field), dimension(sys_size), intent(in) :: q_cons_vf
-        real(kind(0.0d0)), dimension(2, 2), intent(out) :: TJac
+        real(kind(0.0_wp)), dimension(2, 2), intent(out) :: TJac
 
-        real(kind(0.0d0)) :: ml, mT, TS, dFdT, dTdm, dTdp ! mass of the reacting fluid, total reacting mass, and auxiliary variables
+        real(kind(0.0_wp)) :: ml, mT, TS, dFdT, dTdm, dTdp ! mass of the reacting fluid, total reacting mass, and auxiliary variables
 
         ! mass of the reacting liquid
         ml = q_cons_vf(lp + contxb - 1)%sf(j, k, l)
@@ -615,10 +614,10 @@ contains
                 + mCVGP)
 
         dFdT = &
-            -(cvs(lp)*gs_min(lp) - cvs(vp)*gs_min(vp))*DLOG(TS) &
+            -(cvs(lp)*gs_min(lp) - cvs(vp)*gs_min(vp))*log(TS) &
             - (qvps(lp) - qvps(vp)) &
-            + cvs(lp)*(gs_min(lp) - 1)*DLOG(pS + ps_inf(lp)) &
-            - cvs(vp)*(gs_min(vp) - 1)*DLOG(pS + ps_inf(vp))
+            + cvs(lp)*(gs_min(lp) - 1)*log(pS + ps_inf(lp)) &
+            - cvs(vp)*(gs_min(vp) - 1)*log(pS + ps_inf(vp))
 
         dTdm = -(cvs(lp)*(gs_min(lp) - 1)/(pS + ps_inf(lp)) &
                  - cvs(vp)*(gs_min(vp) - 1)/(pS + ps_inf(vp)))*TS**2
@@ -665,8 +664,8 @@ contains
 
         ! intermediate elements of J^{-1}
         InvJac(1, 1) = Jac(2, 2)
-        InvJac(1, 2) = -1.0d0*Jac(1, 2)
-        InvJac(2, 1) = -1.0d0*Jac(2, 1)
+        InvJac(1, 2) = -1.0_wp*Jac(1, 2)
+        InvJac(2, 1) = -1.0_wp*Jac(2, 1)
         InvJac(2, 2) = Jac(1, 1)
 
         ! elements of J^{T}
@@ -700,12 +699,12 @@ contains
 #endif
 
         integer, intent(in) :: j, k, l
-        real(kind(0.0d0)), intent(in) :: mCPD, mCVGP, mQD
+        real(kind(0.0_wp)), intent(in) :: mCPD, mCVGP, mQD
         type(scalar_field), dimension(sys_size), intent(in) :: q_cons_vf
-        real(kind(0.0d0)), intent(in) :: pS, rhoe
-        real(kind(0.0d0)), dimension(2), intent(out) :: R2D
+        real(kind(0.0_wp)), intent(in) :: pS, rhoe
+        real(kind(0.0_wp)), dimension(2), intent(out) :: R2D
 
-        real(kind(0.0d0)) :: ml, mT, TS !< mass of the reacting liquid, total reacting mass, equilibrium temperature
+        real(kind(0.0_wp)) :: ml, mT, TS !< mass of the reacting liquid, total reacting mass, equilibrium temperature
 
         ! mass of the reacting liquid
         ml = q_cons_vf(lp + contxb - 1)%sf(j, k, l)
@@ -721,9 +720,9 @@ contains
 
         ! Gibbs Free Energy Equality condition (DG)
         R2D(1) = TS*((cvs(lp)*gs_min(lp) - cvs(vp)*gs_min(vp)) &
-                     *(1 - DLOG(TS)) - (qvps(lp) - qvps(vp)) &
-                     + cvs(lp)*(gs_min(lp) - 1)*DLOG(pS + ps_inf(lp)) &
-                     - cvs(vp)*(gs_min(vp) - 1)*DLOG(pS + ps_inf(vp))) &
+                     *(1 - log(TS)) - (qvps(lp) - qvps(vp)) &
+                     + cvs(lp)*(gs_min(lp) - 1)*log(pS + ps_inf(lp)) &
+                     - cvs(vp)*(gs_min(vp) - 1)*log(pS + ps_inf(vp))) &
                  + qvs(lp) - qvs(vp)
 
         ! Constant Energy Process condition (DE)
@@ -750,19 +749,19 @@ contains
         !$acc routine seq
 #endif
 
-        real(kind(0.0d0)), intent(in) :: pSat
-        real(kind(0.0d0)), intent(out) :: TSat
-        real(kind(0.0d0)), intent(in) :: TSIn
+        real(kind(0.0_wp)), intent(in) :: pSat
+        real(kind(0.0_wp)), intent(out) :: TSat
+        real(kind(0.0_wp)), intent(in) :: TSIn
 
-        real(kind(0.0d0)) :: dFdT, FT, Om !< auxiliary variables
+        real(kind(0.0_wp)) :: dFdT, FT, Om !< auxiliary variables
 
         ! Generic loop iterators
         integer :: ns
 
-        if ((pSat == 0.0d0) .and. (TSIn == 0.0d0)) then
+        if ((pSat == 0.0_wp) .and. (TSIn == 0.0_wp)) then
 
             ! assigning Saturation temperature
-            TSat = 0.0d0
+            TSat = 0.0_wp
 
         else
 
@@ -774,24 +773,24 @@ contains
             ns = 0
 
             ! underrelaxation factor
-            Om = 1.0d-3
-            do while ((DABS(FT) > ptgalpha_eps) .or. (ns == 0))
+            Om = 1.0e-3_wp
+            do while ((abs(FT) > ptgalpha_eps) .or. (ns == 0))
                 ! increasing counter
                 ns = ns + 1
 
                 ! calculating residual
                 FT = TSat*((cvs(lp)*gs_min(lp) - cvs(vp)*gs_min(vp)) &
-                           *(1 - DLOG(TSat)) - (qvps(lp) - qvps(vp)) &
-                           + cvs(lp)*(gs_min(lp) - 1)*DLOG(pSat + ps_inf(lp)) &
-                           - cvs(vp)*(gs_min(vp) - 1)*DLOG(pSat + ps_inf(vp))) &
+                           *(1 - log(TSat)) - (qvps(lp) - qvps(vp)) &
+                           + cvs(lp)*(gs_min(lp) - 1)*log(pSat + ps_inf(lp)) &
+                           - cvs(vp)*(gs_min(vp) - 1)*log(pSat + ps_inf(vp))) &
                      + qvs(lp) - qvs(vp)
 
                 ! calculating the jacobian
                 dFdT = &
-                    -(cvs(lp)*gs_min(lp) - cvs(vp)*gs_min(vp))*DLOG(TSat) &
+                    -(cvs(lp)*gs_min(lp) - cvs(vp)*gs_min(vp))*log(TSat) &
                     - (qvps(lp) - qvps(vp)) &
-                    + cvs(lp)*(gs_min(lp) - 1)*DLOG(pSat + ps_inf(lp)) &
-                    - cvs(vp)*(gs_min(vp) - 1)*DLOG(pSat + ps_inf(vp))
+                    + cvs(lp)*(gs_min(lp) - 1)*log(pSat + ps_inf(lp)) &
+                    - cvs(vp)*(gs_min(vp) - 1)*log(pSat + ps_inf(vp))
 
                 ! updating saturation temperature
                 TSat = TSat - Om*FT/dFdT
diff --git a/src/common/m_precision_select.f90 b/src/common/m_precision_select.f90
new file mode 100644
index 000000000..3d3fa0383
--- /dev/null
+++ b/src/common/m_precision_select.f90
@@ -0,0 +1,38 @@
+!> @file m_precision_select.f90
+!! @brief Contains module m_precision_select
+
+!> @brief This file contains the definition of floating point used in MFC
+module m_precision_select
+
+    ! use, intrinsic :: iso_c_binding
+
+#ifdef MFC_MPI
+    use mpi                    !< Message passing interface (MPI) module
+#endif
+
+    implicit none
+
+    ! Define the available precision types
+    integer, parameter :: single_precision = selected_real_kind(6, 37)
+    integer, parameter :: double_precision = selected_real_kind(15, 307)
+
+    integer, parameter :: sp = single_precision
+    integer, parameter :: dp = double_precision
+
+    ! Set the working precision (wp) to single or double
+#ifdef MFC_SINGLE_PRECISION
+    integer, parameter :: wp = single_precision  ! Change to single_precision if needed
+#else
+    integer, parameter :: wp = double_precision
+#endif
+
+#ifdef MFC_MPI
+    ! Set mpi_p based on wp using the merge intrinsic function
+    integer, parameter :: mpi_p = merge(MPI_DOUBLE_PRECISION, MPI_REAL, wp == double_precision)
+    integer, parameter :: mpi_2p = merge(MPI_2DOUBLE_PRECISION, MPI_2REAL, wp == double_precision)
+#else
+    integer, parameter :: mpi_p = -100  ! Default value when MPI is not used
+    integer, parameter :: mpi_2p = -100
+#endif
+
+end module m_precision_select
diff --git a/src/common/m_variables_conversion.fpp b/src/common/m_variables_conversion.fpp
index f6fd7e554..428caf8c3 100644
--- a/src/common/m_variables_conversion.fpp
+++ b/src/common/m_variables_conversion.fpp
@@ -51,22 +51,22 @@ module m_variables_conversion
 
     !! In simulation, gammas, pi_infs, and qvs are already declared in m_global_variables
 #ifndef MFC_SIMULATION
-    real(kind(0d0)), allocatable, public, dimension(:) :: gammas, gs_min, pi_infs, ps_inf, cvs, qvs, qvps
+    real(wp), allocatable, public, dimension(:) :: gammas, gs_min, pi_infs, ps_inf, cvs, qvs, qvps
     !$acc declare create(gammas, gs_min, pi_infs, ps_inf, cvs, qvs, qvps)
 #endif
 
-    real(kind(0d0)), allocatable, dimension(:) :: Gs
+    real(wp), allocatable, dimension(:) :: Gs
     integer, allocatable, dimension(:) :: bubrs
-    real(kind(0d0)), allocatable, dimension(:, :) :: Res
+    real(wp), allocatable, dimension(:, :) :: Res
     !$acc declare create(bubrs, Gs, Res)
 
     integer :: is1b, is2b, is3b, is1e, is2e, is3e
     !$acc declare create(is1b, is2b, is3b, is1e, is2e, is3e)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :), public :: rho_sf !< Scalar density function
-    real(kind(0d0)), allocatable, dimension(:, :, :), public :: gamma_sf !< Scalar sp. heat ratio function
-    real(kind(0d0)), allocatable, dimension(:, :, :), public :: pi_inf_sf !< Scalar liquid stiffness function
-    real(kind(0d0)), allocatable, dimension(:, :, :), public :: qv_sf !< Scalar liquid energy reference function
+    real(wp), allocatable, dimension(:, :, :), public :: rho_sf !< Scalar density function
+    real(wp), allocatable, dimension(:, :, :), public :: gamma_sf !< Scalar sp. heat ratio function
+    real(wp), allocatable, dimension(:, :, :), public :: pi_inf_sf !< Scalar liquid stiffness function
+    real(wp), allocatable, dimension(:, :, :), public :: qv_sf !< Scalar liquid energy reference function
 
 contains
 
@@ -86,10 +86,10 @@ contains
 
         type(scalar_field), dimension(sys_size), intent(in) :: q_vf
         integer, intent(in) :: i, j, k
-        real(kind(0d0)), intent(out), target :: rho, gamma, pi_inf, qv
-        real(kind(0d0)), optional, dimension(2), intent(out) :: Re_K
-        real(kind(0d0)), optional, intent(out) :: G_K
-        real(kind(0d0)), optional, dimension(num_fluids), intent(in) :: G
+        real(wp), intent(out), target :: rho, gamma, pi_inf, qv
+        real(wp), optional, dimension(2), intent(out) :: Re_K
+        real(wp), optional, intent(out) :: G_K
+        real(wp), optional, dimension(num_fluids), intent(in) :: G
 
         if (model_eqns == 1) then        ! Gamma/pi_inf model
             call s_convert_mixture_to_mixture_variables(q_vf, i, j, k, &
@@ -125,17 +125,17 @@ contains
         !$acc routine seq
 #endif
 
-        real(kind(0d0)), intent(in) :: energy, alf
-        real(kind(0d0)), intent(in) :: dyn_p
-        real(kind(0d0)), intent(in) :: pi_inf, gamma, rho, qv
-        real(kind(0d0)), intent(out) :: pres, T
-        real(kind(0d0)), intent(in), optional :: stress, mom, G
+        real(wp), intent(in) :: energy, alf
+        real(wp), intent(in) :: dyn_p
+        real(wp), intent(in) :: pi_inf, gamma, rho, qv
+        real(wp), intent(out) :: pres, T
+        real(wp), intent(in), optional :: stress, mom, G
 
         ! Chemistry
-        real(kind(0d0)), dimension(1:num_species), intent(in) :: rhoYks
-        real(kind(0d0)) :: E_e
-        real(kind(0d0)) :: e_Per_Kg, Pdyn_Per_Kg
-        real(kind(0d0)), dimension(1:num_species) :: Y_rs
+        real(wp), dimension(1:num_species), intent(in) :: rhoYks
+        real(wp) :: E_e
+        real(wp) :: e_Per_Kg, Pdyn_Per_Kg
+        real(wp), dimension(1:num_species) :: Y_rs
 
         integer :: s !< Generic loop iterator
 
@@ -146,7 +146,7 @@ contains
             if ((model_eqns /= 4) .and. (bubbles .neqv. .true.)) then
                 pres = (energy - dyn_p - pi_inf - qv)/gamma
             else if ((model_eqns /= 4) .and. bubbles) then
-                pres = ((energy - dyn_p)/(1.d0 - alf) - pi_inf - qv)/gamma
+                pres = ((energy - dyn_p)/(1._wp - alf) - pi_inf - qv)/gamma
             else
                 pres = (pref + pi_inf)* &
                        (energy/ &
@@ -156,22 +156,22 @@ contains
 
             if (hypoelasticity .and. present(G)) then
                 ! calculate elastic contribution to Energy
-                E_e = 0d0
+                E_e = 0._wp
                 do s = stress_idx%beg, stress_idx%end
                     if (G > 0) then
-                        E_e = E_e + ((stress/rho)**2d0)/(4d0*G)
+                        E_e = E_e + ((stress/rho)**2._wp)/(4._wp*G)
                         ! Additional terms in 2D and 3D
                         if ((s == stress_idx%beg + 1) .or. &
                             (s == stress_idx%beg + 3) .or. &
                             (s == stress_idx%beg + 4)) then
-                            E_e = E_e + ((stress/rho)**2d0)/(4d0*G)
+                            E_e = E_e + ((stress/rho)**2._wp)/(4._wp*G)
                         end if
                     end if
                 end do
 
                 pres = ( &
                        energy - &
-                       0.5d0*(mom**2.d0)/rho - &
+                       0.5_wp*(mom**2._wp)/rho - &
                        pi_inf - qv - E_e &
                        )/gamma
 
@@ -183,7 +183,7 @@ contains
             e_Per_Kg = energy/rho
             Pdyn_Per_Kg = dyn_p/rho
 
-            call get_temperature(e_Per_Kg - Pdyn_Per_Kg, 1200d0, Y_rs, .true., T)
+            call get_temperature(e_Per_Kg - Pdyn_Per_Kg, 1200._wp, Y_rs, .true., T)
             call get_pressure(rho, T, Y_rs, pres)
 
         #:endif
@@ -209,22 +209,22 @@ contains
         type(scalar_field), dimension(sys_size), intent(in) :: q_vf
         integer, intent(in) :: i, j, k
 
-        real(kind(0d0)), intent(out), target :: rho
-        real(kind(0d0)), intent(out), target :: gamma
-        real(kind(0d0)), intent(out), target :: pi_inf
-        real(kind(0d0)), intent(out), target :: qv
+        real(wp), intent(out), target :: rho
+        real(wp), intent(out), target :: gamma
+        real(wp), intent(out), target :: pi_inf
+        real(wp), intent(out), target :: qv
 
-        real(kind(0d0)), optional, dimension(2), intent(out) :: Re_K
+        real(wp), optional, dimension(2), intent(out) :: Re_K
 
-        real(kind(0d0)), optional, intent(out) :: G_K
-        real(kind(0d0)), optional, dimension(num_fluids), intent(in) :: G
+        real(wp), optional, intent(out) :: G_K
+        real(wp), optional, dimension(num_fluids), intent(in) :: G
 
         ! Transferring the density, the specific heat ratio function and the
         ! liquid stiffness function, respectively
         rho = q_vf(1)%sf(i, j, k)
         gamma = q_vf(gamma_idx)%sf(i, j, k)
         pi_inf = q_vf(pi_inf_idx)%sf(i, j, k)
-        qv = 0d0 ! keep this value nill for now. For future adjustment
+        qv = 0._wp ! keep this value nill for now. For future adjustment
 
         ! Post process requires rho_sf/gamma_sf/pi_inf_sf/qv_sf to also be updated
 #ifdef MFC_POST_PROCESS
@@ -257,17 +257,17 @@ contains
 
         integer, intent(in) :: j, k, l
 
-        real(kind(0d0)), intent(out), target :: rho
-        real(kind(0d0)), intent(out), target :: gamma
-        real(kind(0d0)), intent(out), target :: pi_inf
-        real(kind(0d0)), intent(out), target :: qv
+        real(wp), intent(out), target :: rho
+        real(wp), intent(out), target :: gamma
+        real(wp), intent(out), target :: pi_inf
+        real(wp), intent(out), target :: qv
 
-        real(kind(0d0)), optional, dimension(2), intent(out) :: Re_K
-        real(kind(0d0)), optional, intent(out) :: G_K
-        real(kind(0d0)), optional, dimension(num_fluids), intent(in) :: G
+        real(wp), optional, dimension(2), intent(out) :: Re_K
+        real(wp), optional, intent(out) :: G_K
+        real(wp), optional, dimension(num_fluids), intent(in) :: G
 
         integer :: i, q
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho_K, alpha_K
+        real(wp), dimension(num_fluids) :: alpha_rho_K, alpha_K
 
         ! Constraining the partial densities and the volume fractions within
         ! their physical bounds to make sure that any mixture variables that
@@ -281,11 +281,11 @@ contains
         if (mpp_lim) then
 
             do i = 1, num_fluids
-                alpha_rho_K(i) = max(0d0, alpha_rho_K(i))
-                alpha_K(i) = min(max(0d0, alpha_K(i)), 1d0)
+                alpha_rho_K(i) = max(0._wp, alpha_rho_K(i))
+                alpha_K(i) = min(max(0._wp, alpha_K(i)), 1._wp)
             end do
 
-            alpha_K = alpha_K/max(sum(alpha_K), 1d-16)
+            alpha_K = alpha_K/max(sum(alpha_K), 1e-16_wp)
 
         end if
 
@@ -298,7 +298,7 @@ contains
             pi_inf = fluid_pp(1)%pi_inf   !qK_vf(pi_inf_idx)%sf(i,j,k)
             qv = fluid_pp(1)%qv
         else if ((model_eqns == 2) .and. bubbles) then
-            rho = 0d0; gamma = 0d0; pi_inf = 0d0; qv = 0d0
+            rho = 0._wp; gamma = 0._wp; pi_inf = 0._wp; qv = 0._wp
 
             if (mpp_lim .and. (num_fluids > 2)) then
                 do i = 1, num_fluids
@@ -337,14 +337,14 @@ contains
             if (num_fluids == 1) then ! need to consider case with num_fluids >= 2
                 do i = 1, 2
 
-                    Re_K(i) = dflt_real; if (Re_size(i) > 0) Re_K(i) = 0d0
+                    Re_K(i) = dflt_real; if (Re_size(i) > 0) Re_K(i) = 0._wp
 
                     do q = 1, Re_size(i)
                         Re_K(i) = (1 - alpha_K(Re_idx(i, q)))/fluid_pp(Re_idx(i, q))%Re(i) &
                                   + Re_K(i)
                     end do
 
-                    Re_K(i) = 1d0/max(Re_K(i), sgm_eps)
+                    Re_K(i) = 1._wp/max(Re_K(i), sgm_eps)
 
                 end do
             end if
@@ -381,17 +381,17 @@ contains
 
         integer, intent(in) :: k, l, r
 
-        real(kind(0d0)), intent(out), target :: rho
-        real(kind(0d0)), intent(out), target :: gamma
-        real(kind(0d0)), intent(out), target :: pi_inf
-        real(kind(0d0)), intent(out), target :: qv
+        real(wp), intent(out), target :: rho
+        real(wp), intent(out), target :: gamma
+        real(wp), intent(out), target :: pi_inf
+        real(wp), intent(out), target :: qv
 
-        real(kind(0d0)), optional, dimension(2), intent(out) :: Re_K
+        real(wp), optional, dimension(2), intent(out) :: Re_K
             !! Partial densities and volume fractions
-        real(kind(0d0)), optional, intent(out) :: G_K
-        real(kind(0d0)), optional, dimension(num_fluids), intent(in) :: G
+        real(wp), optional, intent(out) :: G_K
+        real(wp), optional, dimension(num_fluids), intent(in) :: G
 
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho_K, alpha_K !<
+        real(wp), dimension(num_fluids) :: alpha_rho_K, alpha_K !<
 
         integer :: i, j !< Generic loop iterator
 
@@ -406,18 +406,18 @@ contains
         if (mpp_lim) then
 
             do i = 1, num_fluids
-                alpha_rho_K(i) = max(0d0, alpha_rho_K(i))
-                alpha_K(i) = min(max(0d0, alpha_K(i)), 1d0)
+                alpha_rho_K(i) = max(0._wp, alpha_rho_K(i))
+                alpha_K(i) = min(max(0._wp, alpha_K(i)), 1._wp)
             end do
 
-            alpha_K = alpha_K/max(sum(alpha_K), 1d-16)
+            alpha_K = alpha_K/max(sum(alpha_K), 1e-16_wp)
 
         end if
 
         ! Calculating the density, the specific heat ratio function, the
         ! liquid stiffness function, and the energy reference function,
         ! respectively, from the species analogs
-        rho = 0d0; gamma = 0d0; pi_inf = 0d0; qv = 0d0
+        rho = 0._wp; gamma = 0._wp; pi_inf = 0._wp; qv = 0._wp
 
         do i = 1, num_fluids
             rho = rho + alpha_rho_K(i)
@@ -430,24 +430,24 @@ contains
         ! Computing the shear and bulk Reynolds numbers from species analogs
         do i = 1, 2
 
-            Re_K(i) = dflt_real; if (Re_size(i) > 0) Re_K(i) = 0d0
+            Re_K(i) = dflt_real; if (Re_size(i) > 0) Re_K(i) = 0._wp
 
             do j = 1, Re_size(i)
                 Re_K(i) = alpha_K(Re_idx(i, j))/fluid_pp(Re_idx(i, j))%Re(i) &
                           + Re_K(i)
             end do
 
-            Re_K(i) = 1d0/max(Re_K(i), sgm_eps)
+            Re_K(i) = 1._wp/max(Re_K(i), sgm_eps)
 
         end do
 #endif
 
         if (present(G_K)) then
-            G_K = 0d0
+            G_K = 0._wp
             do i = 1, num_fluids
                 G_K = G_K + alpha_K(i)*G(i)
             end do
-            G_K = max(0d0, G_K)
+            G_K = max(0._wp, G_K)
         end if
 
         ! Post process requires rho_sf/gamma_sf/pi_inf_sf/qv_sf to also be updated
@@ -470,36 +470,36 @@ contains
         !$acc routine seq
 #endif
 
-        real(kind(0d0)), intent(out) :: rho_K, gamma_K, pi_inf_K, qv_K
+        real(wp), intent(out) :: rho_K, gamma_K, pi_inf_K, qv_K
 
-        real(kind(0d0)), dimension(num_fluids), intent(inout) :: alpha_rho_K, alpha_K !<
-        real(kind(0d0)), dimension(2), intent(out) :: Re_K
+        real(wp), dimension(num_fluids), intent(inout) :: alpha_rho_K, alpha_K !<
+        real(wp), dimension(2), intent(out) :: Re_K
         !! Partial densities and volume fractions
 
-        real(kind(0d0)), optional, intent(out) :: G_K
-        real(kind(0d0)), optional, dimension(num_fluids), intent(in) :: G
+        real(wp), optional, intent(out) :: G_K
+        real(wp), optional, dimension(num_fluids), intent(in) :: G
 
         integer, intent(in) :: k, l, r
 
         integer :: i, j !< Generic loop iterators
-        real(kind(0d0)) :: alpha_K_sum
+        real(wp) :: alpha_K_sum
 
 #ifdef MFC_SIMULATION
         ! Constraining the partial densities and the volume fractions within
         ! their physical bounds to make sure that any mixture variables that
         ! are derived from them result within the limits that are set by the
         ! fluids physical parameters that make up the mixture
-        rho_K = 0d0
-        gamma_K = 0d0
-        pi_inf_K = 0d0
-        qv_K = 0d0
+        rho_K = 0._wp
+        gamma_K = 0._wp
+        pi_inf_K = 0._wp
+        qv_K = 0._wp
 
-        alpha_K_sum = 0d0
+        alpha_K_sum = 0._wp
 
         if (mpp_lim) then
             do i = 1, num_fluids
-                alpha_rho_K(i) = max(0d0, alpha_rho_K(i))
-                alpha_K(i) = min(max(0d0, alpha_K(i)), 1d0)
+                alpha_rho_K(i) = max(0._wp, alpha_rho_K(i))
+                alpha_K(i) = min(max(0._wp, alpha_K(i)), 1._wp)
                 alpha_K_sum = alpha_K_sum + alpha_K(i)
             end do
 
@@ -515,12 +515,12 @@ contains
         end do
 
         if (present(G_K)) then
-            G_K = 0d0
+            G_K = 0._wp
             do i = 1, num_fluids
                 !TODO: change to use Gs directly here?
                 G_K = G_K + alpha_K(i)*G(i)
             end do
-            G_K = max(0d0, G_K)
+            G_K = max(0._wp, G_K)
         end if
 
         if (viscous) then
@@ -528,14 +528,14 @@ contains
             do i = 1, 2
                 Re_K(i) = dflt_real
 
-                if (Re_size(i) > 0) Re_K(i) = 0d0
+                if (Re_size(i) > 0) Re_K(i) = 0._wp
 
                 do j = 1, Re_size(i)
                     Re_K(i) = alpha_K(Re_idx(i, j))/Res(i, j) &
                               + Re_K(i)
                 end do
 
-                Re_K(i) = 1d0/max(Re_K(i), sgm_eps)
+                Re_K(i) = 1._wp/max(Re_K(i), sgm_eps)
 
             end do
         end if
@@ -552,21 +552,21 @@ contains
         !$acc routine seq
 #endif
 
-        real(kind(0d0)), intent(inout) :: rho_K, gamma_K, pi_inf_K, qv_K
+        real(wp), intent(inout) :: rho_K, gamma_K, pi_inf_K, qv_K
 
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: alpha_K, alpha_rho_K !<
+        real(wp), dimension(num_fluids), intent(in) :: alpha_K, alpha_rho_K !<
             !! Partial densities and volume fractions
 
-        real(kind(0d0)), dimension(2), intent(out) :: Re_K
+        real(wp), dimension(2), intent(out) :: Re_K
         integer, intent(in) :: k, l, r
 
         integer :: i, j !< Generic loop iterators
 
 #ifdef MFC_SIMULATION
-        rho_K = 0d0
-        gamma_K = 0d0
-        pi_inf_K = 0d0
-        qv_K = 0d0
+        rho_K = 0._wp
+        gamma_K = 0._wp
+        pi_inf_K = 0._wp
+        qv_K = 0._wp
 
         if (mpp_lim .and. (model_eqns == 2) .and. (num_fluids > 2)) then
             do i = 1, num_fluids
@@ -595,14 +595,14 @@ contains
                 do i = 1, 2
                     Re_K(i) = dflt_real
 
-                    if (Re_size(i) > 0) Re_K(i) = 0d0
+                    if (Re_size(i) > 0) Re_K(i) = 0._wp
 
                     do j = 1, Re_size(i)
-                        Re_K(i) = (1d0 - alpha_K(Re_idx(i, j)))/Res(i, j) &
+                        Re_K(i) = (1._wp - alpha_K(Re_idx(i, j)))/Res(i, j) &
                                   + Re_K(i)
                     end do
 
-                    Re_K(i) = 1d0/max(Re_K(i), sgm_eps)
+                    Re_K(i) = 1._wp/max(Re_K(i), sgm_eps)
 
                 end do
             end if
@@ -642,10 +642,10 @@ contains
 
         do i = 1, num_fluids
             gammas(i) = fluid_pp(i)%gamma
-            gs_min(i) = 1.0d0/gammas(i) + 1.0d0
+            gs_min(i) = 1.0_wp/gammas(i) + 1.0_wp
             pi_infs(i) = fluid_pp(i)%pi_inf
             Gs(i) = fluid_pp(i)%G
-            ps_inf(i) = pi_infs(i)/(1.0d0 + gammas(i))
+            ps_inf(i) = pi_infs(i)/(1.0_wp + gammas(i))
             cvs(i) = fluid_pp(i)%cv
             qvs(i) = fluid_pp(i)%qv
             qvps(i) = fluid_pp(i)%qvp
@@ -745,10 +745,11 @@ contains
     subroutine s_initialize_mv(qK_cons_vf, mv)
 
         type(scalar_field), dimension(sys_size), intent(in) :: qK_cons_vf
-        real(kind(0d0)), dimension(idwbuff(1)%beg:, idwbuff(2)%beg:, idwbuff(3)%beg:, 1:, 1:), intent(inout) :: mv
+
+        real(wp), dimension(idwbuff(1)%beg:, idwbuff(2)%beg:, idwbuff(3)%beg:, 1:, 1:), intent(inout) :: mv
 
         integer :: i, j, k, l
-        real(kind(0d0)) :: mu, sig, nbub_sc
+        real(wp) :: mu, sig, nbub_sc
 
         do l = idwbuff(3)%beg, idwbuff(3)%end
             do k = idwbuff(2)%beg, idwbuff(2)%end
@@ -759,12 +760,12 @@ contains
                     !$acc loop seq
                     do i = 1, nb
                         mu = qK_cons_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)/nbub_sc
-                        sig = (qK_cons_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)/nbub_sc - mu**2)**0.5
+                        sig = (qK_cons_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)/nbub_sc - mu**2)**0.5_wp
 
-                        mv(j, k, l, 1, i) = (mass_v0(i))*(mu - sig)**(3d0)/(R0(i)**(3d0))
-                        mv(j, k, l, 2, i) = (mass_v0(i))*(mu - sig)**(3d0)/(R0(i)**(3d0))
-                        mv(j, k, l, 3, i) = (mass_v0(i))*(mu + sig)**(3d0)/(R0(i)**(3d0))
-                        mv(j, k, l, 4, i) = (mass_v0(i))*(mu + sig)**(3d0)/(R0(i)**(3d0))
+                        mv(j, k, l, 1, i) = (mass_v0(i))*(mu - sig)**(3._wp)/(R0(i)**(3._wp))
+                        mv(j, k, l, 2, i) = (mass_v0(i))*(mu - sig)**(3._wp)/(R0(i)**(3._wp))
+                        mv(j, k, l, 3, i) = (mass_v0(i))*(mu + sig)**(3._wp)/(R0(i)**(3._wp))
+                        mv(j, k, l, 4, i) = (mass_v0(i))*(mu + sig)**(3._wp)/(R0(i)**(3._wp))
                     end do
 
                 end do
@@ -776,11 +777,12 @@ contains
     !Initialize pb at the quadrature nodes using isothermal relations (Preston model)
     subroutine s_initialize_pb(qK_cons_vf, mv, pb)
         type(scalar_field), dimension(sys_size), intent(in) :: qK_cons_vf
-        real(kind(0d0)), dimension(idwbuff(1)%beg:, idwbuff(2)%beg:, idwbuff(3)%beg:, 1:, 1:), intent(in) :: mv
-        real(kind(0d0)), dimension(idwbuff(1)%beg:, idwbuff(2)%beg:, idwbuff(3)%beg:, 1:, 1:), intent(inout) :: pb
+
+        real(wp), dimension(idwbuff(1)%beg:, idwbuff(2)%beg:, idwbuff(3)%beg:, 1:, 1:), intent(in) :: mv
+        real(wp), dimension(idwbuff(1)%beg:, idwbuff(2)%beg:, idwbuff(3)%beg:, 1:, 1:), intent(inout) :: pb
 
         integer :: i, j, k, l
-        real(kind(0d0)) :: mu, sig, nbub_sc
+        real(wp) :: mu, sig, nbub_sc
 
         do l = idwbuff(3)%beg, idwbuff(3)%end
             do k = idwbuff(2)%beg, idwbuff(2)%end
@@ -791,13 +793,13 @@ contains
                     !$acc loop seq
                     do i = 1, nb
                         mu = qK_cons_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)/nbub_sc
-                        sig = (qK_cons_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)/nbub_sc - mu**2)**0.5
+                        sig = (qK_cons_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)/nbub_sc - mu**2)**0.5_wp
 
                         !PRESTON (ISOTHERMAL)
-                        pb(j, k, l, 1, i) = (pb0(i))*(R0(i)**(3d0))*(mass_n0(i) + mv(j, k, l, 1, i))/(mu - sig)**(3d0)/(mass_n0(i) + mass_v0(i))
-                        pb(j, k, l, 2, i) = (pb0(i))*(R0(i)**(3d0))*(mass_n0(i) + mv(j, k, l, 2, i))/(mu - sig)**(3d0)/(mass_n0(i) + mass_v0(i))
-                        pb(j, k, l, 3, i) = (pb0(i))*(R0(i)**(3d0))*(mass_n0(i) + mv(j, k, l, 3, i))/(mu + sig)**(3d0)/(mass_n0(i) + mass_v0(i))
-                        pb(j, k, l, 4, i) = (pb0(i))*(R0(i)**(3d0))*(mass_n0(i) + mv(j, k, l, 4, i))/(mu + sig)**(3d0)/(mass_n0(i) + mass_v0(i))
+                        pb(j, k, l, 1, i) = (pb0(i))*(R0(i)**(3._wp))*(mass_n0(i) + mv(j, k, l, 1, i))/(mu - sig)**(3._wp)/(mass_n0(i) + mass_v0(i))
+                        pb(j, k, l, 2, i) = (pb0(i))*(R0(i)**(3._wp))*(mass_n0(i) + mv(j, k, l, 2, i))/(mu - sig)**(3._wp)/(mass_n0(i) + mass_v0(i))
+                        pb(j, k, l, 3, i) = (pb0(i))*(R0(i)**(3._wp))*(mass_n0(i) + mv(j, k, l, 3, i))/(mu + sig)**(3._wp)/(mass_n0(i) + mass_v0(i))
+                        pb(j, k, l, 4, i) = (pb0(i))*(R0(i)**(3._wp))*(mass_n0(i) + mv(j, k, l, 4, i))/(mu + sig)**(3._wp)/(mass_n0(i) + mass_v0(i))
                     end do
                 end do
             end do
@@ -825,31 +827,31 @@ contains
             allocatable, optional, dimension(:), &
             intent(in) :: gm_alphaK_vf
 
-        real(kind(0d0)), dimension(num_fluids) :: alpha_K, alpha_rho_K
-        real(kind(0d0)), dimension(2) :: Re_K
-        real(kind(0d0)) :: rho_K, gamma_K, pi_inf_K, qv_K, dyn_pres_K
+        real(wp), dimension(num_fluids) :: alpha_K, alpha_rho_K
+        real(wp), dimension(2) :: Re_K
+        real(wp) :: rho_K, gamma_K, pi_inf_K, qv_K, dyn_pres_K
 
         #:if MFC_CASE_OPTIMIZATION
 #ifndef MFC_SIMULATION
-            real(kind(0d0)), dimension(:), allocatable :: nRtmp
+            real(wp), dimension(:), allocatable :: nRtmp
 #else
-            real(kind(0d0)), dimension(nb) :: nRtmp
+            real(wp), dimension(nb) :: nRtmp
 #endif
         #:else
-            real(kind(0d0)), dimension(:), allocatable :: nRtmp
+            real(wp), dimension(:), allocatable :: nRtmp
         #:endif
 
-        real(kind(0d0)) :: rhoYks(1:num_species)
+        real(wp) :: rhoYks(1:num_species)
 
-        real(kind(0d0)) :: vftmp, nR3, nbub_sc, R3tmp
+        real(wp) :: vftmp, nR3, nbub_sc, R3tmp
 
-        real(kind(0d0)) :: G_K
+        real(wp) :: G_K
 
-        real(kind(0d0)) :: pres, Yksum, T
+        real(wp) :: pres, Yksum, T
 
         integer :: i, j, k, l, q !< Generic loop iterators
 
-        real(kind(0.d0)) :: ntmp
+        real(wp) :: ntmp
 
         #:if MFC_CASE_OPTIMIZATION
 #ifndef MFC_SIMULATION
@@ -873,7 +875,7 @@ contains
         do l = ibounds(3)%beg, ibounds(3)%end
             do k = ibounds(2)%beg, ibounds(2)%end
                 do j = ibounds(1)%beg, ibounds(1)%end
-                    dyn_pres_K = 0d0
+                    dyn_pres_K = 0._wp
 
                     !$acc loop seq
                     do i = 1, num_fluids
@@ -907,10 +909,10 @@ contains
                     end if
 
                     if (chemistry) then
-                        rho_K = 0d0
+                        rho_K = 0._wp
                         !$acc loop seq
                         do i = chemxb, chemxe
-                            rho_K = rho_K + max(0d0, qK_cons_vf(i)%sf(j, k, l))
+                            rho_K = rho_K + max(0._wp, qK_cons_vf(i)%sf(j, k, l))
                         end do
 
                         !$acc loop seq
@@ -920,7 +922,7 @@ contains
 
                         !$acc loop seq
                         do i = chemxb, chemxe
-                            qK_prim_vf(i)%sf(j, k, l) = max(0d0, qK_cons_vf(i)%sf(j, k, l)/rho_K)
+                            qK_prim_vf(i)%sf(j, k, l) = max(0._wp, qK_cons_vf(i)%sf(j, k, l)/rho_K)
                         end do
 
                         qK_prim_vf(T_idx)%sf(j, k, l) = qK_cons_vf(T_idx)%sf(j, k, l)
@@ -940,7 +942,7 @@ contains
                         if (model_eqns /= 4) then
                             qK_prim_vf(i)%sf(j, k, l) = qK_cons_vf(i)%sf(j, k, l) &
                                                         /rho_K
-                            dyn_pres_K = dyn_pres_K + 5d-1*qK_cons_vf(i)%sf(j, k, l) &
+                            dyn_pres_K = dyn_pres_K + 5e-1_wp*qK_cons_vf(i)%sf(j, k, l) &
                                          *qK_prim_vf(i)%sf(j, k, l)
                         else
                             qK_prim_vf(i)%sf(j, k, l) = qK_cons_vf(i)%sf(j, k, l) &
@@ -1009,13 +1011,13 @@ contains
                             ! subtracting elastic contribution for pressure calculation
                             if (G_K > 1000) then !TODO: check if stable for >0
                                 qK_prim_vf(E_idx)%sf(j, k, l) = qK_prim_vf(E_idx)%sf(j, k, l) - &
-                                                                ((qK_prim_vf(i)%sf(j, k, l)**2d0)/(4d0*G_K))/gamma_K
+                                                                ((qK_prim_vf(i)%sf(j, k, l)**2._wp)/(4._wp*G_K))/gamma_K
                                 ! extra terms in 2 and 3D
                                 if ((i == strxb + 1) .or. &
                                     (i == strxb + 3) .or. &
                                     (i == strxb + 4)) then
                                     qK_prim_vf(E_idx)%sf(j, k, l) = qK_prim_vf(E_idx)%sf(j, k, l) - &
-                                                                    ((qK_prim_vf(i)%sf(j, k, l)**2d0)/(4d0*G_K))/gamma_K
+                                                                    ((qK_prim_vf(i)%sf(j, k, l)**2._wp)/(4._wp*G_K))/gamma_K
                                 end if
                             end if
                         end do
@@ -1059,21 +1061,21 @@ contains
         ! Density, specific heat ratio function, liquid stiffness function
         ! and dynamic pressure, as defined in the incompressible flow sense,
         ! respectively
-        real(kind(0d0)) :: rho
-        real(kind(0d0)) :: gamma
-        real(kind(0d0)) :: pi_inf
-        real(kind(0d0)) :: qv
-        real(kind(0d0)) :: dyn_pres
-        real(kind(0d0)) :: nbub, R3, vftmp, R3tmp
-        real(kind(0d0)), dimension(nb) :: Rtmp
-        real(kind(0d0)) :: G = 0d0
-        real(kind(0d0)), dimension(2) :: Re_K
+        real(wp) :: rho
+        real(wp) :: gamma
+        real(wp) :: pi_inf
+        real(wp) :: qv
+        real(wp) :: dyn_pres
+        real(wp) :: nbub, R3, vftmp, R3tmp
+        real(wp), dimension(nb) :: Rtmp
+        real(wp) :: G = 0._wp
+        real(wp), dimension(2) :: Re_K
 
         integer :: i, j, k, l, q !< Generic loop iterators
         integer :: spec
 
-        real(kind(0d0)), dimension(num_species) :: Ys
-        real(kind(0d0)) :: e_mix, mix_mol_weight, T
+        real(wp), dimension(num_species) :: Ys
+        real(wp) :: e_mix, mix_mol_weight, T
 
 #ifndef MFC_SIMULATION
         ! Converting the primitive variables to the conservative variables
@@ -1098,13 +1100,13 @@ contains
 
                     ! Zeroing out the dynamic pressure since it is computed
                     ! iteratively by cycling through the velocity equations
-                    dyn_pres = 0d0
+                    dyn_pres = 0._wp
 
                     ! Computing momenta and dynamic pressure from velocity
                     do i = momxb, momxe
                         q_cons_vf(i)%sf(j, k, l) = rho*q_prim_vf(i)%sf(j, k, l)
                         dyn_pres = dyn_pres + q_cons_vf(i)%sf(j, k, l)* &
-                                   q_prim_vf(i)%sf(j, k, l)/2d0
+                                   q_prim_vf(i)%sf(j, k, l)/2._wp
                     end do
 
                     if (chemistry) then
@@ -1131,11 +1133,11 @@ contains
                         else if ((model_eqns /= 4) .and. (bubbles)) then
                             ! \tilde{E} = dyn_pres + (1-\alf)(\Gamma p_l + \Pi_inf)
                             q_cons_vf(E_idx)%sf(j, k, l) = dyn_pres + &
-                                                           (1.d0 - q_prim_vf(alf_idx)%sf(j, k, l))* &
+                                                           (1._wp - q_prim_vf(alf_idx)%sf(j, k, l))* &
                                                            (gamma*q_prim_vf(E_idx)%sf(j, k, l) + pi_inf)
                         else
                             !Tait EOS, no conserved energy variable
-                            q_cons_vf(E_idx)%sf(j, k, l) = 0.
+                            q_cons_vf(E_idx)%sf(j, k, l) = 0._wp
                         end if
                     end if
 
@@ -1166,13 +1168,13 @@ contains
                             end if
                         else
                             !Initialize R3 averaging over R0 and R directions
-                            R3tmp = 0d0
+                            R3tmp = 0._wp
                             do i = 1, nb
-                                R3tmp = R3tmp + weight(i)*0.5d0*(Rtmp(i) + sigR)**3d0
-                                R3tmp = R3tmp + weight(i)*0.5d0*(Rtmp(i) - sigR)**3d0
+                                R3tmp = R3tmp + weight(i)*0.5_wp*(Rtmp(i) + sigR)**3._wp
+                                R3tmp = R3tmp + weight(i)*0.5_wp*(Rtmp(i) - sigR)**3._wp
                             end do
                             !Initialize nb
-                            nbub = 3d0*q_prim_vf(alf_idx)%sf(j, k, l)/(4d0*pi*R3tmp)
+                            nbub = 3._wp*q_prim_vf(alf_idx)%sf(j, k, l)/(4._wp*pi*R3tmp)
                         end if
 
                         if (j == 0 .and. k == 0 .and. l == 0) print *, 'In convert, nbub:', nbub
@@ -1188,13 +1190,13 @@ contains
                             ! adding elastic contribution
                             if (G > 1000) then
                                 q_cons_vf(E_idx)%sf(j, k, l) = q_cons_vf(E_idx)%sf(j, k, l) + &
-                                                               (q_prim_vf(i)%sf(j, k, l)**2d0)/(4d0*G)
+                                                               (q_prim_vf(i)%sf(j, k, l)**2._wp)/(4._wp*G)
                                 ! extra terms in 2 and 3D
                                 if ((i == stress_idx%beg + 1) .or. &
                                     (i == stress_idx%beg + 3) .or. &
                                     (i == stress_idx%beg + 4)) then
                                     q_cons_vf(E_idx)%sf(j, k, l) = q_cons_vf(E_idx)%sf(j, k, l) + &
-                                                                   (q_prim_vf(i)%sf(j, k, l)**2d0)/(4d0*G)
+                                                                   (q_prim_vf(i)%sf(j, k, l)**2._wp)/(4._wp*G)
                                 end if
                             end if
                         end do
@@ -1232,27 +1234,27 @@ contains
                                                      is1, is2, is3, s2b, s3b)
 
         integer, intent(in) :: s2b, s3b
-        real(kind(0d0)), dimension(0:, s2b:, s3b:, 1:), intent(in) :: qK_prim_vf
-        real(kind(0d0)), dimension(0:, s2b:, s3b:, 1:), intent(inout) :: FK_vf
-        real(kind(0d0)), dimension(0:, s2b:, s3b:, advxb:), intent(inout) :: FK_src_vf
+        real(wp), dimension(0:, s2b:, s3b:, 1:), intent(in) :: qK_prim_vf
+        real(wp), dimension(0:, s2b:, s3b:, 1:), intent(inout) :: FK_vf
+        real(wp), dimension(0:, s2b:, s3b:, advxb:), intent(inout) :: FK_src_vf
 
         type(int_bounds_info), intent(in) :: is1, is2, is3
 
         ! Partial densities, density, velocity, pressure, energy, advection
         ! variables, the specific heat ratio and liquid stiffness functions,
         ! the shear and volume Reynolds numbers and the Weber numbers
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho_K
-        real(kind(0d0)), dimension(num_fluids) :: alpha_K
-        real(kind(0d0)) :: rho_K
-        real(kind(0d0)), dimension(num_dims) :: vel_K
-        real(kind(0d0)) :: vel_K_sum
-        real(kind(0d0)) :: pres_K
-        real(kind(0d0)) :: E_K
-        real(kind(0d0)) :: gamma_K
-        real(kind(0d0)) :: pi_inf_K
-        real(kind(0d0)) :: qv_K
-        real(kind(0d0)), dimension(2) :: Re_K
-        real(kind(0d0)) :: G_K
+        real(wp), dimension(num_fluids) :: alpha_rho_K
+        real(wp), dimension(num_fluids) :: alpha_K
+        real(wp) :: rho_K
+        real(wp), dimension(num_dims) :: vel_K
+        real(wp) :: vel_K_sum
+        real(wp) :: pres_K
+        real(wp) :: E_K
+        real(wp) :: gamma_K
+        real(wp) :: pi_inf_K
+        real(wp) :: qv_K
+        real(wp), dimension(2) :: Re_K
+        real(wp) :: G_K
 
         integer :: i, j, k, l !< Generic loop iterators
 
@@ -1284,10 +1286,10 @@ contains
                         vel_K(i) = qK_prim_vf(j, k, l, contxe + i)
                     end do
 
-                    vel_K_sum = 0d0
+                    vel_K_sum = 0._wp
                     !$acc loop seq
                     do i = 1, num_dims
-                        vel_K_sum = vel_K_sum + vel_K(i)**2d0
+                        vel_K_sum = vel_K_sum + vel_K(i)**2._wp
                     end do
 
                     pres_K = qK_prim_vf(j, k, l, E_idx)
@@ -1305,7 +1307,7 @@ contains
 
                     ! Computing the energy from the pressure
                     E_K = gamma_K*pres_K + pi_inf_K &
-                          + 5d-1*rho_K*vel_K_sum + qv_K
+                          + 5e-1_wp*rho_K*vel_K_sum + qv_K
 
                     ! mass flux, this should be \alpha_i \rho_i u_i
                     !$acc loop seq
@@ -1327,7 +1329,7 @@ contains
                     if (riemann_solver == 1) then
                         !$acc loop seq
                         do i = advxb, advxe
-                            FK_vf(j, k, l, i) = 0d0
+                            FK_vf(j, k, l, i) = 0._wp
                             FK_src_vf(j, k, l, i) = alpha_K(i - E_idx)
                         end do
 
@@ -1381,57 +1383,58 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), intent(in) :: pres
-        real(kind(0d0)), intent(in) :: rho, gamma, pi_inf
-        real(kind(0d0)), intent(in) :: H
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: adv
-        real(kind(0d0)), intent(in) :: vel_sum
-        real(kind(0d0)), intent(in) :: c_c
-        real(kind(0d0)), intent(out) :: c
-
-        real(kind(0d0)) :: blkmod1, blkmod2
-        real(kind(0d0)) :: Tolerance
+
+        real(wp), intent(in) :: pres
+        real(wp), intent(in) :: rho, gamma, pi_inf
+        real(wp), intent(in) :: H
+        real(wp), dimension(num_fluids), intent(in) :: adv
+        real(wp), intent(in) :: vel_sum
+        real(wp), intent(in) :: c_c
+        real(wp), intent(out) :: c
+
+        real(wp) :: blkmod1, blkmod2
+        real(wp) :: Tolerance
         integer :: q
 
         if (chemistry) then
             if (avg_state == 1 .and. abs(c_c) > Tolerance) then
-                c = sqrt(c_c - (gamma - 1.0d0)*(vel_sum - H))
+                c = sqrt(c_c - (gamma - 1.0_wp)*(vel_sum - H))
             else
-                c = sqrt((1.0d0 + 1.0d0/gamma)*pres/rho)
+                c = sqrt((1.0_wp + 1.0_wp/gamma)*pres/rho)
             end if
         else
             if (alt_soundspeed) then
-                blkmod1 = ((gammas(1) + 1d0)*pres + &
+                blkmod1 = ((gammas(1) + 1._wp)*pres + &
                            pi_infs(1))/gammas(1)
-                blkmod2 = ((gammas(2) + 1d0)*pres + &
+                blkmod2 = ((gammas(2) + 1._wp)*pres + &
                            pi_infs(2))/gammas(2)
-                c = (1d0/(rho*(adv(1)/blkmod1 + adv(2)/blkmod2)))
+                c = (1._wp/(rho*(adv(1)/blkmod1 + adv(2)/blkmod2)))
             elseif (model_eqns == 3) then
-                c = 0d0
+                c = 0._wp
                 !$acc loop seq
                 do q = 1, num_fluids
-                    c = c + adv(q)*(1d0/gammas(q) + 1d0)* &
-                        (pres + pi_infs(q)/(gammas(q) + 1d0))
+                    c = c + adv(q)*(1._wp/gammas(q) + 1._wp)* &
+                        (pres + pi_infs(q)/(gammas(q) + 1._wp))
                 end do
                 c = c/rho
             elseif (((model_eqns == 4) .or. (model_eqns == 2 .and. bubbles))) then
                 ! Sound speed for bubble mmixture to order O(\alpha)
 
                 if (mpp_lim .and. (num_fluids > 1)) then
-                    c = (1d0/gamma + 1d0)* &
-                        (pres + pi_inf/(gamma + 1d0))/rho
+                    c = (1._wp/gamma + 1._wp)* &
+                        (pres + pi_inf/(gamma + 1._wp))/rho
                 else
                     c = &
-                        (1d0/gamma + 1d0)* &
-                        (pres + pi_inf/(gamma + 1d0))/ &
-                        (rho*(1d0 - adv(num_fluids)))
+                        (1._wp/gamma + 1._wp)* &
+                        (pres + pi_inf/(gamma + 1._wp))/ &
+                        (rho*(1._wp - adv(num_fluids)))
                 end if
             else
-                c = ((H - 5d-1*vel_sum)/gamma)
+                c = ((H - 5e-1*vel_sum)/gamma)
             end if
 
-            if (mixture_err .and. c < 0d0) then
-                c = 100.d0*sgm_eps
+            if (mixture_err .and. c < 0._wp) then
+                c = 100._wp*sgm_eps
             else
                 c = sqrt(c)
             end if
diff --git a/src/post_process/m_checker.fpp b/src/post_process/m_checker.fpp
index 2b2bf88e6..817e2ce00 100644
--- a/src/post_process/m_checker.fpp
+++ b/src/post_process/m_checker.fpp
@@ -104,7 +104,7 @@ contains
 
         do i = 1, num_fluids
             call s_int_to_str(i, iStr)
-            @:PROHIBIT(.not. f_is_default(schlieren_alpha(i)) .and. schlieren_alpha(i) <= 0d0, &
+            @:PROHIBIT(.not. f_is_default(schlieren_alpha(i)) .and. schlieren_alpha(i) <= 0._wp, &
                 "schlieren_alpha("//trim(iStr)//") must be greater than zero")
             @:PROHIBIT(.not. f_is_default(schlieren_alpha(i)) .and. i > num_fluids, &
                 "Index of schlieren_alpha("//trim(iStr)//") exceeds the total number of fluids")
diff --git a/src/post_process/m_data_input.f90 b/src/post_process/m_data_input.f90
index 48694092b..5fb944734 100644
--- a/src/post_process/m_data_input.f90
+++ b/src/post_process/m_data_input.f90
@@ -74,7 +74,7 @@ subroutine s_read_serial_data_files(t_step)
             !! Generic string used to store the location of a particular file
 
         character(LEN= &
-                  int(floor(log10(real(sys_size, kind(0d0))))) + 1) :: file_num !<
+                  int(floor(log10(real(sys_size, wp)))) + 1) :: file_num !<
             !! Used to store the variable position, in character form, of the
             !! currently manipulated conservative variable file
 
@@ -140,7 +140,7 @@ subroutine s_read_serial_data_files(t_step)
         dx(0:m) = x_cb(0:m) - x_cb(-1:m - 1)
 
         ! Computing the cell-center locations
-        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2d0
+        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2._wp
 
         ! ==================================================================
 
@@ -167,7 +167,7 @@ subroutine s_read_serial_data_files(t_step)
             dy(0:n) = y_cb(0:n) - y_cb(-1:n - 1)
 
             ! Computing the cell-center locations
-            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2d0
+            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2._wp
 
             ! ==================================================================
 
@@ -194,7 +194,7 @@ subroutine s_read_serial_data_files(t_step)
                 dz(0:p) = z_cb(0:p) - z_cb(-1:p - 1)
 
                 ! Computing the cell-center locations
-                z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2d0
+                z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2._wp
 
             end if
 
@@ -255,11 +255,11 @@ subroutine s_read_parallel_data_files(t_step)
 
 #ifdef MFC_MPI
 
-        real(kind(0d0)), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb
+        real(wp), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb
 
         integer :: ifile, ierr, data_size
         integer, dimension(MPI_STATUS_SIZE) :: status
-        real(kind(0d0)) :: start, finish
+        real(wp) :: start, finish
         integer(KIND=MPI_OFFSET_KIND) :: disp
         integer(KIND=MPI_OFFSET_KIND) :: m_MOK, n_MOK, p_MOK
         integer(KIND=MPI_OFFSET_KIND) :: WP_MOK, var_MOK, str_MOK
@@ -284,7 +284,7 @@ subroutine s_read_parallel_data_files(t_step)
         if (file_exist) then
             data_size = m_glb + 2
             call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-            call MPI_FILE_READ(ifile, x_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+            call MPI_FILE_READ(ifile, x_cb_glb, data_size, mpi_p, status, ierr)
             call MPI_FILE_CLOSE(ifile, ierr)
         else
             call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -295,7 +295,7 @@ subroutine s_read_parallel_data_files(t_step)
         ! Computing the cell width distribution
         dx(0:m) = x_cb(0:m) - x_cb(-1:m - 1)
         ! Computing the cell center location
-        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2d0
+        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2._wp
 
         if (n > 0) then
             ! Read in cell boundary locations in y-direction
@@ -305,7 +305,7 @@ subroutine s_read_parallel_data_files(t_step)
             if (file_exist) then
                 data_size = n_glb + 2
                 call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-                call MPI_FILE_READ(ifile, y_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                call MPI_FILE_READ(ifile, y_cb_glb, data_size, mpi_p, status, ierr)
                 call MPI_FILE_CLOSE(ifile, ierr)
             else
                 call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -316,7 +316,7 @@ subroutine s_read_parallel_data_files(t_step)
             ! Computing the cell width distribution
             dy(0:n) = y_cb(0:n) - y_cb(-1:n - 1)
             ! Computing the cell center location
-            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2d0
+            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2._wp
 
             if (p > 0) then
                 ! Read in cell boundary locations in z-direction
@@ -326,7 +326,7 @@ subroutine s_read_parallel_data_files(t_step)
                 if (file_exist) then
                     data_size = p_glb + 2
                     call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-                    call MPI_FILE_READ(ifile, z_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                    call MPI_FILE_READ(ifile, z_cb_glb, data_size, mpi_p, status, ierr)
                     call MPI_FILE_CLOSE(ifile, ierr)
                 else
                     call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -337,7 +337,7 @@ subroutine s_read_parallel_data_files(t_step)
                 ! Computing the cell width distribution
                 dz(0:p) = z_cb(0:p) - z_cb(-1:p - 1)
                 ! Computing the cell center location
-                z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2d0
+                z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2._wp
             end if
         end if
 
@@ -365,8 +365,8 @@ subroutine s_read_parallel_data_files(t_step)
                 m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
                 n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
                 p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-                WP_MOK = int(8d0, MPI_OFFSET_KIND)
-                MOK = int(1d0, MPI_OFFSET_KIND)
+                WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+                MOK = int(1._wp, MPI_OFFSET_KIND)
                 str_MOK = int(name_len, MPI_OFFSET_KIND)
                 NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -376,14 +376,14 @@ subroutine s_read_parallel_data_files(t_step)
                         var_MOK = int(i, MPI_OFFSET_KIND)
 
                         call MPI_FILE_READ_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                               MPI_DOUBLE_PRECISION, status, ierr)
+                                               mpi_p, status, ierr)
                     end do
                 else
                     do i = 1, adv_idx%end
                         var_MOK = int(i, MPI_OFFSET_KIND)
 
                         call MPI_FILE_READ_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                               MPI_DOUBLE_PRECISION, status, ierr)
+                                               mpi_p, status, ierr)
                     end do
                 end if
 
@@ -439,8 +439,8 @@ subroutine s_read_parallel_data_files(t_step)
                 m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
                 n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
                 p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-                WP_MOK = int(8d0, MPI_OFFSET_KIND)
-                MOK = int(1d0, MPI_OFFSET_KIND)
+                WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+                MOK = int(1._wp, MPI_OFFSET_KIND)
                 str_MOK = int(name_len, MPI_OFFSET_KIND)
                 NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -452,10 +452,10 @@ subroutine s_read_parallel_data_files(t_step)
                         ! Initial displacement to skip at beginning of file
                         disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                               MPI_DOUBLE_PRECISION, status, ierr)
+                                               mpi_p, status, ierr)
                     end do
                 else
                     do i = 1, sys_size
@@ -464,10 +464,10 @@ subroutine s_read_parallel_data_files(t_step)
                         ! Initial displacement to skip at beginning of file
                         disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                               MPI_DOUBLE_PRECISION, status, ierr)
+                                               mpi_p, status, ierr)
                     end do
                 end if
 
@@ -554,7 +554,7 @@ subroutine s_populate_grid_variables_buffer_regions
         end do
 
         do i = 1, buff_size
-            x_cc(-i) = x_cc(1 - i) - (dx(1 - i) + dx(-i))/2d0
+            x_cc(-i) = x_cc(1 - i) - (dx(1 - i) + dx(-i))/2._wp
         end do
 
         ! Ghost-cell extrapolation BC at the end
@@ -590,7 +590,7 @@ subroutine s_populate_grid_variables_buffer_regions
         end do
 
         do i = 1, buff_size
-            x_cc(m + i) = x_cc(m + (i - 1)) + (dx(m + (i - 1)) + dx(m + i))/2d0
+            x_cc(m + i) = x_cc(m + (i - 1)) + (dx(m + (i - 1)) + dx(m + i))/2._wp
         end do
 
         ! END: Populating Buffer Regions in the x-direction ================
@@ -632,7 +632,7 @@ subroutine s_populate_grid_variables_buffer_regions
             end do
 
             do i = 1, buff_size
-                y_cc(-i) = y_cc(1 - i) - (dy(1 - i) + dy(-i))/2d0
+                y_cc(-i) = y_cc(1 - i) - (dy(1 - i) + dy(-i))/2._wp
             end do
 
             ! Ghost-cell extrapolation BC at the end
@@ -668,7 +668,7 @@ subroutine s_populate_grid_variables_buffer_regions
             end do
 
             do i = 1, buff_size
-                y_cc(n + i) = y_cc(n + (i - 1)) + (dy(n + (i - 1)) + dy(n + i))/2d0
+                y_cc(n + i) = y_cc(n + (i - 1)) + (dy(n + (i - 1)) + dy(n + i))/2._wp
             end do
 
             ! END: Populating Buffer Regions in the y-direction ================
@@ -710,7 +710,7 @@ subroutine s_populate_grid_variables_buffer_regions
                 end do
 
                 do i = 1, buff_size
-                    z_cc(-i) = z_cc(1 - i) - (dz(1 - i) + dz(-i))/2d0
+                    z_cc(-i) = z_cc(1 - i) - (dz(1 - i) + dz(-i))/2._wp
                 end do
 
                 ! Ghost-cell extrapolation BC at the end
@@ -746,7 +746,7 @@ subroutine s_populate_grid_variables_buffer_regions
                 end do
 
                 do i = 1, buff_size
-                    z_cc(p + i) = z_cc(p + (i - 1)) + (dz(p + (i - 1)) + dz(p + i))/2d0
+                    z_cc(p + i) = z_cc(p + (i - 1)) + (dz(p + (i - 1)) + dz(p + i))/2._wp
                 end do
 
             end if
diff --git a/src/post_process/m_data_output.fpp b/src/post_process/m_data_output.fpp
index 784dd7c00..5e0a1111e 100644
--- a/src/post_process/m_data_output.fpp
+++ b/src/post_process/m_data_output.fpp
@@ -41,20 +41,20 @@ module m_data_output
     ! database file(s). Note that for 1D simulations, q_root_sf is employed to
     ! gather the flow variable(s) from all sub-domains on to the root process.
     ! If the run is not parallel, but serial, then q_root_sf is equal to q_sf.
-    real(kind(0d0)), allocatable, dimension(:, :, :), public :: q_sf
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: q_root_sf
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: cyl_q_sf
+    real(wp), allocatable, dimension(:, :, :), public :: q_sf
+    real(wp), allocatable, dimension(:, :, :) :: q_root_sf
+    real(wp), allocatable, dimension(:, :, :) :: cyl_q_sf
     ! Single precision storage for flow variables
-    real(kind(0.0)), allocatable, dimension(:, :, :), public :: q_sf_s
-    real(kind(0.0)), allocatable, dimension(:, :, :) :: q_root_sf_s
-    real(kind(0.0)), allocatable, dimension(:, :, :) :: cyl_q_sf_s
+    real(sp), allocatable, dimension(:, :, :), public :: q_sf_s
+    real(sp), allocatable, dimension(:, :, :) :: q_root_sf_s
+    real(sp), allocatable, dimension(:, :, :) :: cyl_q_sf_s
 
     ! The spatial and data extents array variables contain information about the
     ! minimum and maximum values of the grid and flow variable(s), respectively.
     ! The purpose of bookkeeping this information is to boost the visualization
     ! of the Silo-HDF5 database file(s) in VisIt.
-    real(kind(0d0)), allocatable, dimension(:, :) :: spatial_extents
-    real(kind(0d0)), allocatable, dimension(:, :) :: data_extents
+    real(wp), allocatable, dimension(:, :) :: spatial_extents
+    real(wp), allocatable, dimension(:, :) :: data_extents
 
     ! The size of the ghost zone layer at beginning of each coordinate direction
     ! (lo) and at end of each coordinate direction (hi). Adding this information
@@ -102,7 +102,7 @@ module m_data_output
 
 contains
 
-    subroutine s_initialize_data_output_module
+    subroutine s_initialize_data_output_module() ! ----------------------------
         ! Description: Computation of parameters, allocation procedures, and/or
         !              any other tasks needed to properly setup the module
 
@@ -409,9 +409,9 @@ contains
 
         ! END: Querying Number of Flow Variable(s) in Binary Output ========
 
-    end subroutine s_initialize_data_output_module
+    end subroutine s_initialize_data_output_module ! --------------------------
 
-    subroutine s_open_formatted_database_file(t_step)
+    subroutine s_open_formatted_database_file(t_step) ! --------------------
         ! Description: This subroutine opens a new formatted database file, or
         !              replaces an old one, and readies it for the data storage
         !              of the grid and the flow variable(s) associated with the
@@ -424,7 +424,7 @@ contains
         !              not performed in multidimensions.
 
         ! Time-step that is currently being post-processed
-        integer, intent(in) :: t_step
+        integer, intent(IN) :: t_step
 
         ! Generic string used to store the location of a particular file
         character(LEN=len_trim(case_dir) + 3*name_len) :: file_loc
@@ -441,7 +441,7 @@ contains
             ! Creating formatted database slave file at the above location
             ! and setting up the structure of the file and its header info
             ierr = DBCREATE(trim(file_loc), len_trim(file_loc), &
-                            DB_CLOBBER, DB_LOCAL, 'MFC', 8, &
+                            DB_CLOBBER, DB_LOCAL, 'MFC v3.0', 8, &
                             DB_HDF5, dbfile)
 
             ! Verifying that the creation and setup process of the formatted
@@ -462,7 +462,7 @@ contains
                 file_loc = trim(rootdir)//trim(file_loc)
 
                 ierr = DBCREATE(trim(file_loc), len_trim(file_loc), &
-                                DB_CLOBBER, DB_LOCAL, 'MFC', 8, &
+                                DB_CLOBBER, DB_LOCAL, 'MFC v3.0', 8, &
                                 DB_HDF5, dbroot)
 
                 if (dbroot == -1) then
@@ -528,9 +528,9 @@ contains
 
         ! END: Binary Database Format ======================================
 
-    end subroutine s_open_formatted_database_file
+    end subroutine s_open_formatted_database_file ! ------------------------
 
-    subroutine s_write_grid_to_formatted_database_file(t_step)
+    subroutine s_write_grid_to_formatted_database_file(t_step) ! -----------
         ! Description: The general objective of this subroutine is to write the
         !              necessary grid data to the formatted database file, for
         !              the current time-step, t_step. The local processor will
@@ -551,7 +551,7 @@ contains
         !              subroutine s_write_variable_to_formatted_database_file.
 
         ! Time-step that is currently being post-processed
-        integer, intent(in) :: t_step
+        integer, intent(IN) :: t_step
 
         ! Bookkeeping variables storing the name and type of mesh that is
         ! handled by the local processor(s). Note that due to an internal
@@ -623,18 +623,10 @@ contains
 
             if (precision == 1) then
                 if (p > 0) then
-                    do i = -1 - offset_z%beg, p + offset_z%end
-                        z_cb_s(i) = real(z_cb(i))
-                    end do
-                else
-                    do i = -1 - offset_x%beg, m + offset_x%end
-                        x_cb_s(i) = real(x_cb(i))
-                    end do
-
-                    do i = -1 - offset_y%beg, n + offset_y%end
-                        y_cb_s(i) = real(y_cb(i))
-                    end do
+                    z_cb_s = real(z_cb, sp)
                 end if
+                x_cb_s = real(x_cb, sp)
+                y_cb_s = real(y_cb, sp)
             end if
 
             #:for PRECISION, SFX, DBT in [(1,'_s','DB_FLOAT'),(2,'',"DB_DOUBLE")]
@@ -670,6 +662,7 @@ contains
                     end if
                 end if
             #:endfor
+
             ! END: Silo-HDF5 Database Format ===================================
 
             ! Binary Database Format ===========================================
@@ -681,17 +674,17 @@ contains
             ! in multidimensions.
             if (p > 0) then
                 if (precision == 1) then
-                    write (dbfile) real(x_cb, kind(0.0)), &
-                        real(y_cb, kind(0.0)), &
-                        real(z_cb, kind(0.0))
+                    write (dbfile) real(x_cb, sp), &
+                        real(y_cb, sp), &
+                        real(z_cb, sp)
                 else
                     write (dbfile) x_cb, y_cb, z_cb
                 end if
 
             elseif (n > 0) then
                 if (precision == 1) then
-                    write (dbfile) real(x_cb, kind(0.0)), &
-                        real(y_cb, kind(0.0))
+                    write (dbfile) real(x_cb, sp), &
+                        real(y_cb, sp)
                 else
                     write (dbfile) x_cb, y_cb
                 end if
@@ -702,7 +695,7 @@ contains
             else
 
                 if (precision == 1) then
-                    write (dbfile) real(x_cb, kind(0.0))
+                    write (dbfile) real(x_cb, wp)
                 else
                     write (dbfile) x_cb
                 end if
@@ -715,7 +708,7 @@ contains
 
                 if (proc_rank == 0) then
                     if (precision == 1) then
-                        write (dbroot) real(x_root_cb, kind(0.0))
+                        write (dbroot) real(x_root_cb, wp)
                     else
                         write (dbroot) x_root_cb
                     end if
@@ -727,7 +720,7 @@ contains
 
         ! ==================================================================
 
-    end subroutine s_write_grid_to_formatted_database_file
+    end subroutine s_write_grid_to_formatted_database_file ! ---------------
 
     subroutine s_write_variable_to_formatted_database_file(varname, t_step)
         ! Description: The goal of this subroutine is to write to the formatted
@@ -748,10 +741,10 @@ contains
 
         ! Name of the flow variable, which will be written to the formatted
         ! database file at the current time-step, t_step
-        character(LEN=*), intent(in) :: varname
+        character(LEN=*), intent(IN) :: varname
 
         ! Time-step that is currently being post-processed
-        integer, intent(in) :: t_step
+        integer, intent(IN) :: t_step
 
         ! Bookkeeping variables storing the name and type of flow variable
         ! that is about to be handled by the local processor(s). Note that
@@ -762,7 +755,7 @@ contains
 
         ! Generic loop iterator
         integer :: i, j, k
-        real(kind(0d0)) :: start, finish
+        real(wp) :: start, finish
 
         ! Silo-HDF5 Database Format ========================================
 
@@ -775,30 +768,57 @@ contains
             ! and write it to the formatted database master file.
             if (n == 0) then
 
+                if (precision == 1 .and. wp == dp) then
+                    x_cc_s = real(x_cc, sp)
+                    q_sf_s = real(q_sf, sp)
+                elseif (precision == 1 .and. wp == sp) then
+                    x_cc_s = x_cc
+                    q_sf_s = q_sf
+                end if
+
                 ! Writing the curve object associated with the local process
                 ! to the formatted database slave file
-                err = DBPUTCURVE(dbfile, trim(varname), len_trim(varname), &
-                                 x_cc(0:m), q_sf, DB_DOUBLE, m + 1, &
-                                 DB_F77NULL, ierr)
+                #:for PRECISION, SFX, DBT in [(1,'_s','DB_FLOAT'),(2,'',"DB_DOUBLE")]
+                    if (precision == ${PRECISION}$) then
+                        err = DBPUTCURVE(dbfile, trim(varname), len_trim(varname), &
+                                         x_cc${SFX}$ (0:m), q_sf${SFX}$, ${DBT}$, m + 1, &
+                                         DB_F77NULL, ierr)
+                    end if
+                #:endfor
 
                 ! Assembling the local grid and flow variable data for the
                 ! entire computational domain on to the root process
+
                 if (num_procs > 1) then
                     call s_mpi_defragment_1d_grid_variable()
                     call s_mpi_defragment_1d_flow_variable(q_sf, q_root_sf)
+
+                    if (precision == 1) then
+                        x_root_cc_s = real(x_root_cc, sp)
+                        q_root_sf_s = real(q_root_sf, sp)
+                    end if
                 else
-                    x_root_cc = x_cc(0:m)
-                    q_root_sf = q_sf
+                    if (precision == 1) then
+                        x_root_cc_s = real(x_cc, sp)
+                        q_root_sf_s = real(q_sf, sp)
+                    else
+                        x_root_cc = x_cc
+                        q_root_sf = q_sf
+                    end if
                 end if
 
                 ! Writing the curve object associated with the root process
                 ! to the formatted database master file
                 if (proc_rank == 0) then
-                    err = DBPUTCURVE(dbroot, trim(varname), &
-                                     len_trim(varname), &
-                                     x_root_cc, q_root_sf, &
-                                     DB_DOUBLE, m_root + 1, &
-                                     DB_F77NULL, ierr)
+                    #:for PRECISION, SFX, DBT in [(1,'_s','DB_FLOAT'),(2,'',"DB_DOUBLE")]
+                        if (precision == ${PRECISION}$) then
+                            err = DBPUTCURVE(dbroot, trim(varname), &
+                                             len_trim(varname), &
+                                             x_root_cc${SFX}$, q_root_sf${SFX}$, &
+                                             ${DBT}$, m_root + 1, &
+                                             DB_F77NULL, ierr)
+                        end if
+                    #:endfor
                 end if
 
                 return
@@ -845,25 +865,52 @@ contains
                 ! Finally, each of the local processor(s) proceeds to write
                 ! the flow variable data that it is responsible for to the
                 ! formatted database slave file.
-
-                if (precision == 1) then
-                    do i = -offset_x%beg, m + offset_x%end
-                        do j = -offset_y%beg, n + offset_y%end
-                            do k = -offset_z%beg, p + offset_z%end
-                                q_sf_s(i, j, k) = real(q_sf(i, j, k))
+                if (wp == dp) then
+                    if (precision == 1) then
+                        do i = -offset_x%beg, m + offset_x%end
+                            do j = -offset_y%beg, n + offset_y%end
+                                do k = -offset_z%beg, p + offset_z%end
+                                    q_sf_s(i, j, k) = real(q_sf(i, j, k), sp)
+                                end do
                             end do
                         end do
-                    end do
-                end if
-
-                if (grid_geometry == 3) then
+                        if (grid_geometry == 3) then
+                            do i = -offset_x%beg, m + offset_x%end
+                                do j = -offset_y%beg, n + offset_y%end
+                                    do k = -offset_z%beg, p + offset_z%end
+                                        cyl_q_sf_s(j, k, i) = q_sf_s(i, j, k)
+                                    end do
+                                end do
+                            end do
+                        end if
+                    else
+                        if (grid_geometry == 3) then
+                            do i = -offset_x%beg, m + offset_x%end
+                                do j = -offset_y%beg, n + offset_y%end
+                                    do k = -offset_z%beg, p + offset_z%end
+                                        cyl_q_sf(j, k, i) = q_sf(i, j, k)
+                                    end do
+                                end do
+                            end do
+                        end if
+                    end if
+                elseif (wp == dp) then
                     do i = -offset_x%beg, m + offset_x%end
                         do j = -offset_y%beg, n + offset_y%end
                             do k = -offset_z%beg, p + offset_z%end
-                                cyl_q_sf(j, k, i) = q_sf(i, j, k)
+                                q_sf_s(i, j, k) = q_sf(i, j, k)
                             end do
                         end do
                     end do
+                    if (grid_geometry == 3) then
+                        do i = -offset_x%beg, m + offset_x%end
+                            do j = -offset_y%beg, n + offset_y%end
+                                do k = -offset_z%beg, p + offset_z%end
+                                    cyl_q_sf_s(j, k, i) = q_sf_s(i, j, k)
+                                end do
+                            end do
+                        end do
+                    end if
                 end if
 
                 #:for PRECISION, SFX, DBT in [(1,'_s','DB_FLOAT'),(2,'',"DB_DOUBLE")]
@@ -906,7 +953,7 @@ contains
             ! Writing the name of the flow variable and its data, associated
             ! with the local processor, to the formatted database slave file
             if (precision == 1) then
-                write (dbfile) varname, real(q_sf, kind(0.0))
+                write (dbfile) varname, real(q_sf, wp)
             else
                 write (dbfile) varname, q_sf
             end if
@@ -924,7 +971,7 @@ contains
 
                 if (proc_rank == 0) then
                     if (precision == 1) then
-                        write (dbroot) varname, real(q_root_sf, kind(0.0))
+                        write (dbroot) varname, real(q_root_sf, wp)
                     else
                         write (dbroot) varname, q_root_sf
                     end if
@@ -936,9 +983,9 @@ contains
 
         ! ==================================================================
 
-    end subroutine s_write_variable_to_formatted_database_file
+    end subroutine s_write_variable_to_formatted_database_file ! -----------
 
-    subroutine s_close_formatted_database_file
+    subroutine s_close_formatted_database_file() ! -------------------------
         ! Description: The purpose of this subroutine is to close any formatted
         !              database file(s) that may be opened at the time-step that
         !              is currently being post-processed. The root process must
@@ -963,9 +1010,9 @@ contains
 
         end if
 
-    end subroutine s_close_formatted_database_file
+    end subroutine s_close_formatted_database_file ! -----------------------
 
-    subroutine s_finalize_data_output_module
+    subroutine s_finalize_data_output_module() ! -------------------------
         ! Description: Deallocation procedures for the module
 
         ! Deallocating the generic storage employed for the flow variable(s)
@@ -989,6 +1036,6 @@ contains
             deallocate (dims)
         end if
 
-    end subroutine s_finalize_data_output_module
+    end subroutine s_finalize_data_output_module ! -----------------------
 
 end module m_data_output
diff --git a/src/post_process/m_derived_variables.fpp b/src/post_process/m_derived_variables.fpp
index e08973bd2..0f03ccb11 100644
--- a/src/post_process/m_derived_variables.fpp
+++ b/src/post_process/m_derived_variables.fpp
@@ -33,7 +33,7 @@ module m_derived_variables
  s_compute_speed_of_sound, &
  s_finalize_derived_variables_module
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: gm_rho_sf !<
+    real(wp), allocatable, dimension(:, :, :) :: gm_rho_sf !<
     !! Gradient magnitude (gm) of the density for each cell of the computational
     !! sub-domain. This variable is employed in the calculation of the numerical
     !! Schlieren function.
@@ -43,9 +43,9 @@ module m_derived_variables
     !! active coordinate directions, the centered family of the finite-difference
     !! schemes is used.
     !> @{
-    real(kind(0d0)), allocatable, dimension(:, :), public :: fd_coeff_x
-    real(kind(0d0)), allocatable, dimension(:, :), public :: fd_coeff_y
-    real(kind(0d0)), allocatable, dimension(:, :), public :: fd_coeff_z
+    real(wp), allocatable, dimension(:, :), public :: fd_coeff_x
+    real(wp), allocatable, dimension(:, :), public :: fd_coeff_y
+    real(wp), allocatable, dimension(:, :), public :: fd_coeff_z
     !> @}
 
     integer, private :: flg  !<
@@ -119,7 +119,7 @@ contains
         !!  @param q_sf Specific heat ratio
     subroutine s_derive_specific_heat_ratio(q_sf)
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-offset_x%beg:m + offset_x%end, &
                       -offset_y%beg:n + offset_y%end, &
                       -offset_z%beg:p + offset_z%end), &
@@ -131,7 +131,7 @@ contains
         do k = -offset_z%beg, p + offset_z%end
             do j = -offset_y%beg, n + offset_y%end
                 do i = -offset_x%beg, m + offset_x%end
-                    q_sf(i, j, k) = 1d0 + 1d0/gamma_sf(i, j, k)
+                    q_sf(i, j, k) = 1._wp + 1._wp/gamma_sf(i, j, k)
                 end do
             end do
         end do
@@ -146,7 +146,7 @@ contains
         !!  @param q_sf Liquid stiffness
     subroutine s_derive_liquid_stiffness(q_sf)
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-offset_x%beg:m + offset_x%end, &
                       -offset_y%beg:n + offset_y%end, &
                       -offset_z%beg:p + offset_z%end), &
@@ -159,7 +159,7 @@ contains
         do k = -offset_z%beg, p + offset_z%end
             do j = -offset_y%beg, n + offset_y%end
                 do i = -offset_x%beg, m + offset_x%end
-                    q_sf(i, j, k) = pi_inf_sf(i, j, k)/(gamma_sf(i, j, k) + 1d0)
+                    q_sf(i, j, k) = pi_inf_sf(i, j, k)/(gamma_sf(i, j, k) + 1._wp)
                 end do
             end do
         end do
@@ -179,7 +179,7 @@ contains
             dimension(sys_size), &
             intent(in) :: q_prim_vf
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-offset_x%beg:m + offset_x%end, &
                       -offset_y%beg:n + offset_y%end, &
                       -offset_z%beg:p + offset_z%end), &
@@ -188,7 +188,7 @@ contains
         integer :: i, j, k !< Generic loop iterators
 
         ! Fluid bulk modulus for alternate sound speed
-        real(kind(0d0)) :: blkmod1, blkmod2
+        real(wp) :: blkmod1, blkmod2
 
         ! Computing speed of sound values from those of pressure, density,
         ! specific heat ratio function and the liquid stiffness function
@@ -198,21 +198,21 @@ contains
 
                     ! Compute mixture sound speed
                     if (alt_soundspeed .neqv. .true.) then
-                        q_sf(i, j, k) = (((gamma_sf(i, j, k) + 1d0)* &
+                        q_sf(i, j, k) = (((gamma_sf(i, j, k) + 1._wp)* &
                                           q_prim_vf(E_idx)%sf(i, j, k) + &
                                           pi_inf_sf(i, j, k))/(gamma_sf(i, j, k)* &
                                                                rho_sf(i, j, k)))
                     else
-                        blkmod1 = ((fluid_pp(1)%gamma + 1d0)*q_prim_vf(E_idx)%sf(i, j, k) + &
+                        blkmod1 = ((fluid_pp(1)%gamma + 1._wp)*q_prim_vf(E_idx)%sf(i, j, k) + &
                                    fluid_pp(1)%pi_inf)/fluid_pp(1)%gamma
-                        blkmod2 = ((fluid_pp(2)%gamma + 1d0)*q_prim_vf(E_idx)%sf(i, j, k) + &
+                        blkmod2 = ((fluid_pp(2)%gamma + 1._wp)*q_prim_vf(E_idx)%sf(i, j, k) + &
                                    fluid_pp(2)%pi_inf)/fluid_pp(2)%gamma
-                        q_sf(i, j, k) = (1d0/(rho_sf(i, j, k)*(q_prim_vf(adv_idx%beg)%sf(i, j, k)/blkmod1 + &
-                                                               (1d0 - q_prim_vf(adv_idx%beg)%sf(i, j, k))/blkmod2)))
+                        q_sf(i, j, k) = (1._wp/(rho_sf(i, j, k)*(q_prim_vf(adv_idx%beg)%sf(i, j, k)/blkmod1 + &
+                                                                 (1._wp - q_prim_vf(adv_idx%beg)%sf(i, j, k))/blkmod2)))
                     end if
 
-                    if (mixture_err .and. q_sf(i, j, k) < 0d0) then
-                        q_sf(i, j, k) = 1d-16
+                    if (mixture_err .and. q_sf(i, j, k) < 0._wp) then
+                        q_sf(i, j, k) = 1e-16_wp
                     else
                         q_sf(i, j, k) = sqrt(q_sf(i, j, k))
                     end if
@@ -236,19 +236,19 @@ contains
 
         type(scalar_field), dimension(sys_size), intent(in) :: q_prim_vf
 
-        real(kind(0d0)), dimension(-offset_x%beg:m + offset_x%end, &
-                                   -offset_y%beg:n + offset_y%end, &
-                                   -offset_z%beg:p + offset_z%end), &
+        real(wp), dimension(-offset_x%beg:m + offset_x%end, &
+                            -offset_y%beg:n + offset_y%end, &
+                            -offset_z%beg:p + offset_z%end), &
             intent(inout) :: q_sf
 
-        real(kind(0d0)) :: top, bottom, slope !< Flux limiter calcs
+        real(wp) :: top, bottom, slope !< Flux limiter calcs
         integer :: j, k, l !< Generic loop iterators
 
         do l = -offset_z%beg, p + offset_z%end
             do k = -offset_y%beg, n + offset_y%end
                 do j = -offset_x%beg, m + offset_x%end
                     if (i == 1) then
-                        if (q_prim_vf(cont_idx%end + i)%sf(j, k, l) >= 0d0) then
+                        if (q_prim_vf(cont_idx%end + i)%sf(j, k, l) >= 0._wp) then
                             top = q_prim_vf(adv_idx%beg)%sf(j, k, l) - &
                                   q_prim_vf(adv_idx%beg)%sf(j - 1, k, l)
                             bottom = q_prim_vf(adv_idx%beg)%sf(j + 1, k, l) - &
@@ -260,7 +260,7 @@ contains
                                      q_prim_vf(adv_idx%beg)%sf(j, k, l)
                         end if
                     elseif (i == 2) then
-                        if (q_prim_vf(cont_idx%end + i)%sf(j, k, l) >= 0d0) then
+                        if (q_prim_vf(cont_idx%end + i)%sf(j, k, l) >= 0._wp) then
                             top = q_prim_vf(adv_idx%beg)%sf(j, k, l) - &
                                   q_prim_vf(adv_idx%beg)%sf(j, k - 1, l)
                             bottom = q_prim_vf(adv_idx%beg)%sf(j, k + 1, l) - &
@@ -272,7 +272,7 @@ contains
                                      q_prim_vf(adv_idx%beg)%sf(j, k, l)
                         end if
                     else
-                        if (q_prim_vf(cont_idx%end + i)%sf(j, k, l) >= 0d0) then
+                        if (q_prim_vf(cont_idx%end + i)%sf(j, k, l) >= 0._wp) then
                             top = q_prim_vf(adv_idx%beg)%sf(j, k, l) - &
                                   q_prim_vf(adv_idx%beg)%sf(j, k, l - 1)
                             bottom = q_prim_vf(adv_idx%beg)%sf(j, k, l + 1) - &
@@ -285,34 +285,34 @@ contains
                         end if
                     end if
 
-                    if (abs(top) < 1d-8) top = 0d0
-                    if (abs(bottom) < 1d-8) bottom = 0d0
+                    if (abs(top) < 1e-8_wp) top = 0._wp
+                    if (abs(bottom) < 1e-8_wp) bottom = 0._wp
 
                     if (top == bottom) then
-                        slope = 1d0
-                        !       ELSEIF((top == 0d0 .AND. bottom /= 0d0) &
+                        slope = 1._wp
+                        !       ELSEIF((top == 0._wp .AND. bottom /= 0._wp) &
                         !               .OR.            &
-                        !           (bottom == 0d0 .AND. top /= 0d0)) THEN
-                        !           slope = 0d0
+                        !           (bottom == 0._wp .AND. top /= 0._wp)) THEN
+                        !           slope = 0._wp
                     else
-                        slope = (top*bottom)/(bottom**2d0 + 1d-16)
+                        slope = (top*bottom)/(bottom**2._wp + 1e-16_wp)
                     end if
 
                     ! Flux limiter function
                     if (flux_lim == 1) then ! MINMOD (MM)
-                        q_sf(j, k, l) = max(0d0, min(1d0, slope))
+                        q_sf(j, k, l) = max(0._wp, min(1._wp, slope))
                     elseif (flux_lim == 2) then ! MUSCL (MC)
-                        q_sf(j, k, l) = max(0d0, min(2d0*slope, 5d-1*(1d0 + slope), 2d0))
+                        q_sf(j, k, l) = max(0._wp, min(2._wp*slope, 5e-1_wp*(1._wp + slope), 2._wp))
                     elseif (flux_lim == 3) then ! OSPRE (OP)
-                        q_sf(j, k, l) = (15d-1*(slope**2d0 + slope))/(slope**2d0 + slope + 1d0)
+                        q_sf(j, k, l) = (15e-1_wp*(slope**2._wp + slope))/(slope**2._wp + slope + 1._wp)
                     elseif (flux_lim == 4) then ! SUPERBEE (SB)
-                        q_sf(j, k, l) = max(0d0, min(1d0, 2d0*slope), min(slope, 2d0))
+                        q_sf(j, k, l) = max(0._wp, min(1._wp, 2._wp*slope), min(slope, 2._wp))
                     elseif (flux_lim == 5) then ! SWEBY (SW) (beta = 1.5)
-                        q_sf(j, k, l) = max(0d0, min(15d-1*slope, 1d0), min(slope, 15d-1))
+                        q_sf(j, k, l) = max(0._wp, min(15e-1_wp*slope, 1._wp), min(slope, 15e-1_wp))
                     elseif (flux_lim == 6) then ! VAN ALBADA (VA)
-                        q_sf(j, k, l) = (slope**2d0 + slope)/(slope**2d0 + 1d0)
+                        q_sf(j, k, l) = (slope**2._wp + slope)/(slope**2._wp + 1._wp)
                     elseif (flux_lim == 7) then ! VAN LEER (VL)
-                        q_sf(j, k, l) = (abs(slope) + slope)/(1d0 + abs(slope))
+                        q_sf(j, k, l) = (abs(slope) + slope)/(1._wp + abs(slope))
                     end if
                 end do
             end do
@@ -321,15 +321,15 @@ contains
 
     !>  Computes the solution to the linear system Ax=b w/ sol = x
         !!  @param A Input matrix
-        !!  @param b right-hand-side
+        !!  @param b right-hane-side
         !!  @param sol Solution
         !!  @param ndim Problem size
     subroutine s_solve_linear_system(A, b, sol, ndim)
 
         integer, intent(in) :: ndim
-        real(kind(0d0)), dimension(ndim, ndim), intent(inout) :: A
-        real(kind(0d0)), dimension(ndim), intent(inout) :: b
-        real(kind(0d0)), dimension(ndim), intent(out) :: sol
+        real(wp), dimension(ndim, ndim), intent(inout) :: A
+        real(wp), dimension(ndim), intent(inout) :: b
+        real(wp), dimension(ndim), intent(out) :: sol
 
         integer, dimension(ndim) :: ipiv
 
@@ -385,7 +385,7 @@ contains
             dimension(sys_size), &
             intent(in) :: q_prim_vf
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-offset_x%beg:m + offset_x%end, &
                       -offset_y%beg:n + offset_y%end, &
                       -offset_z%beg:p + offset_z%end), &
@@ -399,12 +399,12 @@ contains
                 do k = -offset_y%beg, n + offset_y%end
                     do j = -offset_x%beg, m + offset_x%end
 
-                        q_sf(j, k, l) = 0d0
+                        q_sf(j, k, l) = 0._wp
 
                         do r = -fd_number, fd_number
                             if (grid_geometry == 3) then
                                 q_sf(j, k, l) = &
-                                    q_sf(j, k, l) + 1d0/y_cc(k)* &
+                                    q_sf(j, k, l) + 1._wp/y_cc(k)* &
                                     (fd_coeff_y(r, k)*y_cc(r + k)* &
                                      q_prim_vf(mom_idx%end)%sf(j, r + k, l) &
                                      - fd_coeff_z(r, l)* &
@@ -428,7 +428,7 @@ contains
                 do k = -offset_y%beg, n + offset_y%end
                     do j = -offset_x%beg, m + offset_x%end
 
-                        q_sf(j, k, l) = 0d0
+                        q_sf(j, k, l) = 0._wp
 
                         do r = -fd_number, fd_number
                             if (grid_geometry == 3) then
@@ -456,7 +456,7 @@ contains
                 do k = -offset_y%beg, n + offset_y%end
                     do j = -offset_x%beg, m + offset_x%end
 
-                        q_sf(j, k, l) = 0d0
+                        q_sf(j, k, l) = 0._wp
 
                         do r = -fd_number, fd_number
                             q_sf(j, k, l) = &
@@ -484,16 +484,16 @@ contains
             dimension(sys_size), &
             intent(in) :: q_prim_vf
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-offset_x%beg:m + offset_x%end, &
                       -offset_y%beg:n + offset_y%end, &
                       -offset_z%beg:p + offset_z%end), &
             intent(inout) :: q_sf
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(1:3, 1:3) :: q_jacobian_sf, S, S2, O, O2
 
-        real(kind(0d0)) :: trS, trS2, trO2, Q, IIS
+        real(wp) :: trS, trS2, trO2, Q, IIS
         integer :: j, k, l, r, jj, kk !< Generic loop iterators
 
         do l = -offset_z%beg, p + offset_z%end
@@ -501,7 +501,7 @@ contains
                 do j = -offset_x%beg, m + offset_x%end
 
                     ! Get velocity gradient tensor
-                    q_jacobian_sf(:, :) = 0d0
+                    q_jacobian_sf(:, :) = 0._wp
 
                     do r = -fd_number, fd_number
                         do jj = 1, 3
@@ -526,9 +526,9 @@ contains
                     ! Decompose J into asymmetric matrix, S, and a skew-symmetric matrix, O
                     do jj = 1, 3
                         do kk = 1, 3
-                            S(jj, kk) = 0.5d0* &
+                            S(jj, kk) = 0.5_wp* &
                                         (q_jacobian_sf(jj, kk) + q_jacobian_sf(kk, jj))
-                            O(jj, kk) = 0.5d0* &
+                            O(jj, kk) = 0.5_wp* &
                                         (q_jacobian_sf(jj, kk) - q_jacobian_sf(kk, jj))
                         end do
                     end do
@@ -546,11 +546,11 @@ contains
                     end do
 
                     ! Compute Q
-                    Q = 0.5*((O2(1, 1) + O2(2, 2) + O2(3, 3)) - &
-                             (S2(1, 1) + S2(2, 2) + S2(3, 3)))
+                    Q = 0.5_wp*((O2(1, 1) + O2(2, 2) + O2(3, 3)) - &
+                                (S2(1, 1) + S2(2, 2) + S2(3, 3)))
                     trS = S(1, 1) + S(2, 2) + S(3, 3)
-                    IIS = 0.5*((S(1, 1) + S(2, 2) + S(3, 3))**2 - &
-                               (S2(1, 1) + S2(2, 2) + S2(3, 3)))
+                    IIS = 0.5_wp*((S(1, 1) + S(2, 2) + S(3, 3))**2 - &
+                                  (S2(1, 1) + S2(2, 2) + S2(3, 3)))
                     q_sf(j, k, l) = Q + IIS
 
                 end do
@@ -572,22 +572,22 @@ contains
             dimension(sys_size), &
             intent(in) :: q_cons_vf
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(-offset_x%beg:m + offset_x%end, &
                       -offset_y%beg:n + offset_y%end, &
                       -offset_z%beg:p + offset_z%end), &
             intent(inout) :: q_sf
 
-        real(kind(0d0)) :: drho_dx, drho_dy, drho_dz !<
+        real(wp) :: drho_dx, drho_dy, drho_dz !<
             !! Spatial derivatives of the density in the x-, y- and z-directions
 
-        real(kind(0d0)), dimension(2) :: gm_rho_max !<
+        real(wp), dimension(2) :: gm_rho_max !<
             !! Maximum value of the gradient magnitude (gm) of the density field
             !! in entire computational domain and not just the local sub-domain.
             !! The first position in the variable contains the maximum value and
             !! the second contains the rank of the processor on which it occurred.
 
-        real(kind(0d0)) :: alpha_unadv !< Unadvected volume fraction
+        real(wp) :: alpha_unadv !< Unadvected volume fraction
 
         integer :: i, j, k, l !< Generic loop iterators
 
@@ -598,8 +598,8 @@ contains
             do k = -offset_y%beg, n + offset_y%end
                 do j = -offset_x%beg, m + offset_x%end
 
-                    drho_dx = 0d0
-                    drho_dy = 0d0
+                    drho_dx = 0._wp
+                    drho_dy = 0._wp
 
                     do i = -fd_number, fd_number
                         drho_dx = drho_dx + fd_coeff_x(i, j)*rho_sf(i + j, k, l)
@@ -618,7 +618,7 @@ contains
                 do k = -offset_y%beg, n + offset_y%end
                     do j = -offset_x%beg, m + offset_x%end
 
-                        drho_dz = 0d0
+                        drho_dz = 0._wp
 
                         do i = -fd_number, fd_number
                             if (grid_geometry == 3) then
@@ -648,7 +648,7 @@ contains
 
         ! Determining the local maximum of the gradient magnitude of density
         ! and bookkeeping the result, along with rank of the local processor
-        gm_rho_max = (/maxval(gm_rho_sf), real(proc_rank, kind(0d0))/)
+        gm_rho_max = (/maxval(gm_rho_sf), real(proc_rank, wp)/)
 
         ! Comparing the local maximum gradient magnitude of the density on
         ! this processor to the those computed on the remaining processors.
@@ -674,7 +674,7 @@ contains
                 do k = -offset_y%beg, n + offset_y%end
                     do j = -offset_x%beg, m + offset_x%end
 
-                        q_sf(j, k, l) = 0d0
+                        q_sf(j, k, l) = 0._wp
 
                         do i = 1, adv_idx%end - E_idx
                             q_sf(j, k, l) = &
diff --git a/src/post_process/m_global_parameters.fpp b/src/post_process/m_global_parameters.fpp
index b150f23e7..46dedba19 100644
--- a/src/post_process/m_global_parameters.fpp
+++ b/src/post_process/m_global_parameters.fpp
@@ -58,18 +58,19 @@ module m_global_parameters
 
     !> @name Cell-boundary locations in the x-, y- and z-coordinate directions
     !> @{
-    real(kind(0d0)), allocatable, dimension(:) :: x_cb, x_root_cb, y_cb, z_cb
-    real(kind(0.0)), allocatable, dimension(:) :: x_cb_s, y_cb_s, z_cb_s
+    real(wp), allocatable, dimension(:) :: x_cb, x_root_cb, y_cb, z_cb
+    real(wp), allocatable, dimension(:) :: x_cb_s, y_cb_s, z_cb_s
     !> @}
 
     !> @name Cell-center locations in the x-, y- and z-coordinate directions
     !> @{
-    real(kind(0d0)), allocatable, dimension(:) :: x_cc, x_root_cc, y_cc, z_cc
+    real(wp), allocatable, dimension(:) :: x_cc, x_root_cc, y_cc, z_cc
+    real(sp), allocatable, dimension(:) :: x_root_cc_s, x_cc_s
     !> @}
 
     !> Cell-width distributions in the x-, y- and z-coordinate directions
     !> @{
-    real(kind(0d0)), allocatable, dimension(:) :: dx, dy, dz
+    real(wp), allocatable, dimension(:) :: dx, dy, dz
     !> @}
 
     integer :: buff_size !<
@@ -84,9 +85,9 @@ module m_global_parameters
     !> @name IO options for adaptive time-stepping
     !> @{
     logical :: cfl_adap_dt, cfl_const_dt, cfl_dt
-    real(kind(0d0)) :: t_save
-    real(kind(0d0)) :: t_stop
-    real(kind(0d0)) :: cfl_target
+    real(wp) :: t_save
+    real(wp) :: t_stop
+    real(wp) :: cfl_target
     integer :: n_save
     integer :: n_start
     !> @}
@@ -182,7 +183,7 @@ module m_global_parameters
 
     ! ==========================================================================
 
-    real(kind(0d0)), allocatable, dimension(:) :: adv !< Advection variables
+    real(wp), allocatable, dimension(:) :: adv !< Advection variables
 
     ! Formatted Database File(s) Structure Parameters ==========================
 
@@ -231,7 +232,7 @@ module m_global_parameters
     logical :: chem_wrt_T
     !> @}
 
-    real(kind(0d0)), dimension(num_fluids_max) :: schlieren_alpha    !<
+    real(wp), dimension(num_fluids_max) :: schlieren_alpha    !<
     !! Amplitude coefficients of the numerical Schlieren function that are used
     !! to adjust the intensity of numerical Schlieren renderings for individual
     !! fluids. This enables waves and interfaces of varying strengths and in all
@@ -251,34 +252,35 @@ module m_global_parameters
 
     !> @name Reference parameters for Tait EOS
     !> @{
-    real(kind(0d0)) :: rhoref, pref
+    real(wp) :: rhoref, pref
     !> @}
 
     !> @name Bubble modeling variables and parameters
     !> @{
     integer :: nb
-    real(kind(0d0)) :: R0ref
-    real(kind(0d0)) :: Ca, Web, Re_inv
-    real(kind(0d0)), dimension(:), allocatable :: weight, R0, V0
+    real(wp) :: R0ref
+    real(wp) :: Ca, Web, Re_inv
+    real(wp), dimension(:), allocatable :: weight, R0, V0
     logical :: bubbles
     logical :: qbmm
     logical :: polytropic
     logical :: polydisperse
     logical :: adv_n
     integer :: thermal  !< 1 = adiabatic, 2 = isotherm, 3 = transfer
-    real(kind(0d0)) :: R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, G, pv, M_n, M_v
-    real(kind(0d0)), dimension(:), allocatable :: k_n, k_v, pb0, mass_n0, mass_v0, Pe_T
-    real(kind(0d0)), dimension(:), allocatable :: Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN
-    real(kind(0d0)) :: mul0, ss, gamma_v, mu_v
-    real(kind(0d0)) :: gamma_m, gamma_n, mu_n
-    real(kind(0d0)) :: poly_sigma
-    real(kind(0d0)) :: sigR
+    real(wp) :: R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, G, pv, M_n, M_v
+    real(wp), dimension(:), allocatable :: k_n, k_v, pb0, mass_n0, mass_v0, Pe_T
+    real(wp), dimension(:), allocatable :: Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN
+    real(wp) :: mul0, ss, gamma_v, mu_v
+    real(wp) :: gamma_m, gamma_n, mu_n
+    real(wp) :: poly_sigma
+    real(wp) :: sigR
     integer :: nmom
     !> @}
 
     !> @name surface tension coefficient
     !> @{
-    real(kind(0d0)) :: sigma
+
+    real(wp) :: sigma
     logical :: surface_tension
     !> #}
 
@@ -338,8 +340,8 @@ contains
 
         #:for DIM in ['x', 'y', 'z']
             #:for DIR in [1, 2, 3]
-                bc_${DIM}$%vb${DIR}$ = 0d0
-                bc_${DIM}$%ve${DIR}$ = 0d0
+                bc_${DIM}$%vb${DIR}$ = 0._wp
+                bc_${DIM}$%ve${DIR}$ = 0._wp
             #:endfor
         #:endfor
 
@@ -347,9 +349,9 @@ contains
         do i = 1, num_fluids_max
             fluid_pp(i)%gamma = dflt_real
             fluid_pp(i)%pi_inf = dflt_real
-            fluid_pp(i)%cv = 0d0
-            fluid_pp(i)%qv = 0d0
-            fluid_pp(i)%qvp = 0d0
+            fluid_pp(i)%cv = 0._wp
+            fluid_pp(i)%qv = 0._wp
+            fluid_pp(i)%qvp = 0._wp
             fluid_pp(i)%G = dflt_real
         end do
 
@@ -518,12 +520,12 @@ contains
                 end if
 
                 if (nb == 1) then
-                    weight(:) = 1d0
-                    R0(:) = 1d0
-                    V0(:) = 0d0
+                    weight(:) = 1._wp
+                    R0(:) = 1._wp
+                    V0(:) = 0._wp
                 else if (nb > 1) then
                     !call s_simpson
-                    V0(:) = 0d0
+                    V0(:) = 0._wp
                 else
                     stop 'Invalid value of nb'
                 end if
@@ -531,8 +533,8 @@ contains
                 if (polytropic .neqv. .true.) then
                     !call s_initialize_nonpoly
                 else
-                    rhoref = 1.d0
-                    pref = 1.d0
+                    rhoref = 1._wp
+                    pref = 1._wp
                 end if
 
             end if
@@ -613,18 +615,18 @@ contains
                 end do
 
                 if (nb == 1) then
-                    weight(:) = 1d0
-                    R0(:) = 1d0
-                    V0(:) = 0d0
+                    weight(:) = 1._wp
+                    R0(:) = 1._wp
+                    V0(:) = 0._wp
                 else if (nb > 1) then
-                    V0(:) = 0d0
+                    V0(:) = 0._wp
                 else
                     stop 'Invalid value of nb'
                 end if
 
                 if (polytropic) then
-                    rhoref = 1.d0
-                    pref = 1.d0
+                    rhoref = 1._wp
+                    pref = 1._wp
                 end if
             end if
         end if
@@ -726,6 +728,8 @@ contains
                     allocate (z_cb_s(-1 - offset_x%beg:m + offset_x%end))
                 end if
             end if
+        else
+            allocate (x_cc_s(-buff_size:m + buff_size))
         end if
 
         ! Allocating the grid variables in the x-coordinate direction
@@ -753,6 +757,10 @@ contains
             allocate (x_root_cb(-1:m_root))
             allocate (x_root_cc(0:m_root))
 
+            if (precision == 1) then
+                allocate (x_root_cc_s(0:m_root))
+            end if
+
         end if
 
         allocate (adv(num_fluids))
diff --git a/src/post_process/m_mpi_proxy.fpp b/src/post_process/m_mpi_proxy.fpp
index 20c5346d2..3fa7b6990 100644
--- a/src/post_process/m_mpi_proxy.fpp
+++ b/src/post_process/m_mpi_proxy.fpp
@@ -29,8 +29,8 @@ module m_mpi_proxy
     !! processors. Note that these variables are structured as vectors rather
     !! than arrays.
     !> @{
-    real(kind(0d0)), allocatable, dimension(:) :: q_cons_buffer_in
-    real(kind(0d0)), allocatable, dimension(:) :: q_cons_buffer_out
+    real(wp), allocatable, dimension(:) :: q_cons_buffer_in
+    real(wp), allocatable, dimension(:) :: q_cons_buffer_out
     !> @}
 
     !> @name Receive counts and displacement vector variables, respectively, used in
@@ -106,8 +106,8 @@ contains
 
             ! Initially zeroing out the vectorized buffer region variables
             ! to avoid possible underflow from any unused allocated memory
-            q_cons_buffer_in = 0d0
-            q_cons_buffer_out = 0d0
+            q_cons_buffer_in = 0._wp
+            q_cons_buffer_out = 0._wp
 
         end if
 
@@ -182,19 +182,19 @@ contains
         call MPI_BCAST(alpha_wrt(1), num_fluids_max, MPI_LOGICAL, 0, MPI_COMM_WORLD, ierr)
 
         do i = 1, num_fluids_max
-            call MPI_BCAST(fluid_pp(i)%gamma, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
-            call MPI_BCAST(fluid_pp(i)%pi_inf, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
-            call MPI_BCAST(fluid_pp(i)%cv, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
-            call MPI_BCAST(fluid_pp(i)%qv, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
-            call MPI_BCAST(fluid_pp(i)%qvp, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
-            call MPI_BCAST(fluid_pp(i)%G, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%gamma, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%pi_inf, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%cv, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%qv, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%qvp, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%G, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
         end do
 
         #:for VAR in [ 'pref', 'rhoref', 'R0ref', 'poly_sigma', 'Web', 'Ca', &
             & 'Re_inv', 'sigma', 't_save', 't_stop' ]
-            call MPI_BCAST(${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
         #:endfor
-        call MPI_BCAST(schlieren_alpha(1), num_fluids_max, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+        call MPI_BCAST(schlieren_alpha(1), num_fluids_max, mpi_p, 0, MPI_COMM_WORLD, ierr)
 #endif
 
     end subroutine s_mpi_bcast_user_inputs
@@ -213,10 +213,10 @@ contains
 
         ! Temporary # of processors in x-, y- and z-coordinate directions
         ! used during the processor factorization optimization procedure
-        real(kind(0d0)) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z
+        real(wp) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z
 
         ! Processor factorization (fct) minimization parameter
-        real(kind(0d0)) :: fct_min
+        real(wp) :: fct_min
 
         ! Cartesian processor topology communicator
         integer :: MPI_COMM_CART
@@ -262,8 +262,8 @@ contains
                     tmp_num_procs_x = num_procs_x
                     tmp_num_procs_y = num_procs_y
                     tmp_num_procs_z = num_procs_z
-                    fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                       - (n + 1)/tmp_num_procs_y)
+                    fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                         - (n + 1)/tmp_num_procs_y)
 
                     ! Searching for optimal computational domain distribution
                     do i = 1, num_procs
@@ -306,10 +306,10 @@ contains
                     tmp_num_procs_x = num_procs_x
                     tmp_num_procs_y = num_procs_y
                     tmp_num_procs_z = num_procs_z
-                    fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                       - (n + 1)/tmp_num_procs_y) &
-                              + 10d0*abs((n + 1)/tmp_num_procs_y &
-                                         - (p + 1)/tmp_num_procs_z)
+                    fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                         - (n + 1)/tmp_num_procs_y) &
+                              + 10._wp*abs((n + 1)/tmp_num_procs_y &
+                                           - (p + 1)/tmp_num_procs_z)
 
                     ! Searching for optimal computational domain distribution
                     do i = 1, num_procs
@@ -448,8 +448,8 @@ contains
                 ! Computing minimization variable for these initial values
                 tmp_num_procs_x = num_procs_x
                 tmp_num_procs_y = num_procs_y
-                fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                   - (n + 1)/tmp_num_procs_y)
+                fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                     - (n + 1)/tmp_num_procs_y)
 
                 ! Searching for optimal computational domain distribution
                 do i = 1, num_procs
@@ -667,9 +667,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_x%end/bc_x%beg
                     call MPI_SENDRECV(dx(m - buff_size + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 0, &
+                                      mpi_p, bc_x%end, 0, &
                                       dx(-buff_size), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 0, &
+                                      mpi_p, bc_x%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -678,9 +678,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_x%beg/bc_x%beg
                     call MPI_SENDRECV(dx(0), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 1, &
+                                      mpi_p, bc_x%beg, 1, &
                                       dx(-buff_size), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 0, &
+                                      mpi_p, bc_x%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -693,9 +693,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_x%beg/bc_x%end
                     call MPI_SENDRECV(dx(0), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 1, &
+                                      mpi_p, bc_x%beg, 1, &
                                       dx(m + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 1, &
+                                      mpi_p, bc_x%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -704,9 +704,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_x%end/bc_x%end
                     call MPI_SENDRECV(dx(m - buff_size + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 0, &
+                                      mpi_p, bc_x%end, 0, &
                                       dx(m + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 1, &
+                                      mpi_p, bc_x%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -727,9 +727,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_y%end/bc_y%beg
                     call MPI_SENDRECV(dy(n - buff_size + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%end, 0, &
+                                      mpi_p, bc_y%end, 0, &
                                       dy(-buff_size), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%beg, 0, &
+                                      mpi_p, bc_y%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -738,9 +738,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_y%beg/bc_y%beg
                     call MPI_SENDRECV(dy(0), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%beg, 1, &
+                                      mpi_p, bc_y%beg, 1, &
                                       dy(-buff_size), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%beg, 0, &
+                                      mpi_p, bc_y%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -753,9 +753,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_y%beg/bc_y%end
                     call MPI_SENDRECV(dy(0), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%beg, 1, &
+                                      mpi_p, bc_y%beg, 1, &
                                       dy(n + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%end, 1, &
+                                      mpi_p, bc_y%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -764,9 +764,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_y%end/bc_y%end
                     call MPI_SENDRECV(dy(n - buff_size + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%end, 0, &
+                                      mpi_p, bc_y%end, 0, &
                                       dy(n + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_y%end, 1, &
+                                      mpi_p, bc_y%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -787,9 +787,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_z%end/bc_z%beg
                     call MPI_SENDRECV(dz(p - buff_size + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 0, &
+                                      mpi_p, bc_z%end, 0, &
                                       dz(-buff_size), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 0, &
+                                      mpi_p, bc_z%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -798,9 +798,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_z%beg/bc_z%beg
                     call MPI_SENDRECV(dz(0), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 1, &
+                                      mpi_p, bc_z%beg, 1, &
                                       dz(-buff_size), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 0, &
+                                      mpi_p, bc_z%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -813,9 +813,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_z%beg/bc_z%end
                     call MPI_SENDRECV(dz(0), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 1, &
+                                      mpi_p, bc_z%beg, 1, &
                                       dz(p + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 1, &
+                                      mpi_p, bc_z%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -824,9 +824,9 @@ contains
 
                     ! Sending/receiving the data to/from bc_z%end/bc_z%end
                     call MPI_SENDRECV(dz(p - buff_size + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 0, &
+                                      mpi_p, bc_z%end, 0, &
                                       dz(p + 1), buff_size, &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 1, &
+                                      mpi_p, bc_z%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -890,10 +890,10 @@ contains
                     ! Sending/receiving the data to/from bc_x%end/bc_x%beg
                     call MPI_SENDRECV(q_cons_buffer_out(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 0, &
+                                      mpi_p, bc_x%end, 0, &
                                       q_cons_buffer_in(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 0, &
+                                      mpi_p, bc_x%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -918,10 +918,10 @@ contains
                     ! Sending/receiving the data to/from bc_x%beg/bc_x%beg
                     call MPI_SENDRECV(q_cons_buffer_out(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 1, &
+                                      mpi_p, bc_x%beg, 1, &
                                       q_cons_buffer_in(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 0, &
+                                      mpi_p, bc_x%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -970,10 +970,10 @@ contains
                     ! Sending/receiving the data to/from bc_x%beg/bc_x%end
                     call MPI_SENDRECV(q_cons_buffer_out(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%beg, 1, &
+                                      mpi_p, bc_x%beg, 1, &
                                       q_cons_buffer_in(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 1, &
+                                      mpi_p, bc_x%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -998,10 +998,10 @@ contains
                     ! Sending/receiving the data to/from bc_x%end/bc_x%end
                     call MPI_SENDRECV(q_cons_buffer_out(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 0, &
+                                      mpi_p, bc_x%end, 0, &
                                       q_cons_buffer_in(0), &
                                       buff_size*sys_size*(n + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_x%end, 1, &
+                                      mpi_p, bc_x%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1060,11 +1060,11 @@ contains
                     ! Sending/receiving the data to/from bc_y%end/bc_y%beg
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
-                                      (p + 1), MPI_DOUBLE_PRECISION, &
+                                      (p + 1), mpi_p, &
                                       bc_y%end, 0, q_cons_buffer_in(0), &
                                       buff_size*sys_size* &
                                       (m + 2*buff_size + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_y%beg, 0, &
+                                      mpi_p, bc_y%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1090,11 +1090,11 @@ contains
                     ! Sending/receiving the data to/from bc_y%beg/bc_y%beg
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
-                                      (p + 1), MPI_DOUBLE_PRECISION, &
+                                      (p + 1), mpi_p, &
                                       bc_y%beg, 1, q_cons_buffer_in(0), &
                                       buff_size*sys_size* &
                                       (m + 2*buff_size + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_y%beg, 0, &
+                                      mpi_p, bc_y%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1145,11 +1145,11 @@ contains
                     ! Sending/receiving the data to/from bc_y%beg/bc_y%end
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
-                                      (p + 1), MPI_DOUBLE_PRECISION, &
+                                      (p + 1), mpi_p, &
                                       bc_y%beg, 1, q_cons_buffer_in(0), &
                                       buff_size*sys_size* &
                                       (m + 2*buff_size + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_y%end, 1, &
+                                      mpi_p, bc_y%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1176,11 +1176,11 @@ contains
                     ! Sending/receiving the data to/from bc_y%end/bc_y%end
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
-                                      (p + 1), MPI_DOUBLE_PRECISION, &
+                                      (p + 1), mpi_p, &
                                       bc_y%end, 0, q_cons_buffer_in(0), &
                                       buff_size*sys_size* &
                                       (m + 2*buff_size + 1)*(p + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_y%end, 1, &
+                                      mpi_p, bc_y%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1242,11 +1242,11 @@ contains
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 0, &
+                                      mpi_p, bc_z%end, 0, &
                                       q_cons_buffer_in(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 0, &
+                                      mpi_p, bc_z%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1274,11 +1274,11 @@ contains
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 1, &
+                                      mpi_p, bc_z%beg, 1, &
                                       q_cons_buffer_in(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 0, &
+                                      mpi_p, bc_z%beg, 0, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1332,11 +1332,11 @@ contains
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%beg, 1, &
+                                      mpi_p, bc_z%beg, 1, &
                                       q_cons_buffer_in(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 1, &
+                                      mpi_p, bc_z%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1365,11 +1365,11 @@ contains
                     call MPI_SENDRECV(q_cons_buffer_out(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 0, &
+                                      mpi_p, bc_z%end, 0, &
                                       q_cons_buffer_in(0), buff_size* &
                                       sys_size*(m + 2*buff_size + 1)* &
                                       (n + 2*buff_size + 1), &
-                                      MPI_DOUBLE_PRECISION, bc_z%end, 1, &
+                                      mpi_p, bc_z%end, 1, &
                                       MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
                                       ierr)
 
@@ -1415,7 +1415,7 @@ contains
         !!  the second dimension corresponds to the processor rank.
     subroutine s_mpi_gather_spatial_extents(spatial_extents)
 
-        real(kind(0d0)), dimension(1:, 0:), intent(inout) :: spatial_extents
+        real(wp), dimension(1:, 0:), intent(INOUT) :: spatial_extents
 
 #ifdef MFC_MPI
 
@@ -1423,102 +1423,102 @@ contains
         if (p > 0) then
             if (grid_geometry == 3) then
                 ! Minimum spatial extent in the r-direction
-                call MPI_GATHERV(minval(y_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(minval(y_cb), 1, mpi_p, &
                                  spatial_extents(1, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Minimum spatial extent in the theta-direction
-                call MPI_GATHERV(minval(z_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(minval(z_cb), 1, mpi_p, &
                                  spatial_extents(2, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Minimum spatial extent in the z-direction
-                call MPI_GATHERV(minval(x_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(minval(x_cb), 1, mpi_p, &
                                  spatial_extents(3, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Maximum spatial extent in the r-direction
-                call MPI_GATHERV(maxval(y_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(maxval(y_cb), 1, mpi_p, &
                                  spatial_extents(4, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Maximum spatial extent in the theta-direction
-                call MPI_GATHERV(maxval(z_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(maxval(z_cb), 1, mpi_p, &
                                  spatial_extents(5, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Maximum spatial extent in the z-direction
-                call MPI_GATHERV(maxval(x_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(maxval(x_cb), 1, mpi_p, &
                                  spatial_extents(6, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
             else
                 ! Minimum spatial extent in the x-direction
-                call MPI_GATHERV(minval(x_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(minval(x_cb), 1, mpi_p, &
                                  spatial_extents(1, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Minimum spatial extent in the y-direction
-                call MPI_GATHERV(minval(y_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(minval(y_cb), 1, mpi_p, &
                                  spatial_extents(2, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Minimum spatial extent in the z-direction
-                call MPI_GATHERV(minval(z_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(minval(z_cb), 1, mpi_p, &
                                  spatial_extents(3, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Maximum spatial extent in the x-direction
-                call MPI_GATHERV(maxval(x_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(maxval(x_cb), 1, mpi_p, &
                                  spatial_extents(4, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Maximum spatial extent in the y-direction
-                call MPI_GATHERV(maxval(y_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(maxval(y_cb), 1, mpi_p, &
                                  spatial_extents(5, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
 
                 ! Maximum spatial extent in the z-direction
-                call MPI_GATHERV(maxval(z_cb), 1, MPI_DOUBLE_PRECISION, &
+                call MPI_GATHERV(maxval(z_cb), 1, mpi_p, &
                                  spatial_extents(6, 0), recvcounts, 6*displs, &
-                                 MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                                 mpi_p, 0, MPI_COMM_WORLD, &
                                  ierr)
             end if
             ! Simulation is 2D
         else
 
             ! Minimum spatial extent in the x-direction
-            call MPI_GATHERV(minval(x_cb), 1, MPI_DOUBLE_PRECISION, &
+            call MPI_GATHERV(minval(x_cb), 1, mpi_p, &
                              spatial_extents(1, 0), recvcounts, 4*displs, &
-                             MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                             mpi_p, 0, MPI_COMM_WORLD, &
                              ierr)
 
             ! Minimum spatial extent in the y-direction
-            call MPI_GATHERV(minval(y_cb), 1, MPI_DOUBLE_PRECISION, &
+            call MPI_GATHERV(minval(y_cb), 1, mpi_p, &
                              spatial_extents(2, 0), recvcounts, 4*displs, &
-                             MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                             mpi_p, 0, MPI_COMM_WORLD, &
                              ierr)
 
             ! Maximum spatial extent in the x-direction
-            call MPI_GATHERV(maxval(x_cb), 1, MPI_DOUBLE_PRECISION, &
+            call MPI_GATHERV(maxval(x_cb), 1, mpi_p, &
                              spatial_extents(3, 0), recvcounts, 4*displs, &
-                             MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                             mpi_p, 0, MPI_COMM_WORLD, &
                              ierr)
 
             ! Maximum spatial extent in the y-direction
-            call MPI_GATHERV(maxval(y_cb), 1, MPI_DOUBLE_PRECISION, &
+            call MPI_GATHERV(maxval(y_cb), 1, mpi_p, &
                              spatial_extents(4, 0), recvcounts, 4*displs, &
-                             MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                             mpi_p, 0, MPI_COMM_WORLD, &
                              ierr)
 
         end if
@@ -1539,17 +1539,17 @@ contains
         ! Silo-HDF5 database format
         if (format == 1) then
 
-            call MPI_GATHERV(x_cc(0), m + 1, MPI_DOUBLE_PRECISION, &
+            call MPI_GATHERV(x_cc(0), m + 1, mpi_p, &
                              x_root_cc(0), recvcounts, displs, &
-                             MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                             mpi_p, 0, MPI_COMM_WORLD, &
                              ierr)
 
             ! Binary database format
         else
 
-            call MPI_GATHERV(x_cb(0), m + 1, MPI_DOUBLE_PRECISION, &
+            call MPI_GATHERV(x_cb(0), m + 1, mpi_p, &
                              x_root_cb(0), recvcounts, displs, &
-                             MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, &
+                             mpi_p, 0, MPI_COMM_WORLD, &
                              ierr)
 
             if (proc_rank == 0) x_root_cb(-1) = x_cb(-1)
@@ -1570,23 +1570,23 @@ contains
         !!  to each processor's rank.
     subroutine s_mpi_gather_data_extents(q_sf, data_extents)
 
-        real(kind(0d0)), dimension(:, :, :), intent(in) :: q_sf
+        real(wp), dimension(:, :, :), intent(in) :: q_sf
 
-        real(kind(0d0)), &
+        real(wp), &
             dimension(1:2, 0:num_procs - 1), &
             intent(inout) :: data_extents
 
 #ifdef MFC_MPI
 
         ! Minimum flow variable extent
-        call MPI_GATHERV(minval(q_sf), 1, MPI_DOUBLE_PRECISION, &
+        call MPI_GATHERV(minval(q_sf), 1, mpi_p, &
                          data_extents(1, 0), recvcounts, 2*displs, &
-                         MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                         mpi_p, 0, MPI_COMM_WORLD, ierr)
 
         ! Maximum flow variable extent
-        call MPI_GATHERV(maxval(q_sf), 1, MPI_DOUBLE_PRECISION, &
+        call MPI_GATHERV(maxval(q_sf), 1, mpi_p, &
                          data_extents(2, 0), recvcounts, 2*displs, &
-                         MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                         mpi_p, 0, MPI_COMM_WORLD, ierr)
 
 #endif
 
@@ -1600,12 +1600,12 @@ contains
         !!  @param q_root_sf Flow variable defined on the entire computational domain
     subroutine s_mpi_defragment_1d_flow_variable(q_sf, q_root_sf)
 
-        real(kind(0d0)), &
-            dimension(0:m, 0:0, 0:0), &
+        real(wp), &
+            dimension(0:m), &
             intent(in) :: q_sf
 
-        real(kind(0d0)), &
-            dimension(0:m_root, 0:0, 0:0), &
+        real(wp), &
+            dimension(0:m), &
             intent(inout) :: q_root_sf
 
 #ifdef MFC_MPI
@@ -1613,9 +1613,9 @@ contains
         ! Gathering the sub-domain flow variable data from all the processes
         ! and putting it back together for the entire computational domain
         ! on the process with rank 0
-        call MPI_GATHERV(q_sf(0, 0, 0), m + 1, MPI_DOUBLE_PRECISION, &
-                         q_root_sf(0, 0, 0), recvcounts, displs, &
-                         MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+        call MPI_GATHERV(q_sf(0), m + 1, mpi_p, &
+                         q_root_sf(0), recvcounts, displs, &
+                         mpi_p, 0, MPI_COMM_WORLD, ierr)
 
 #endif
 
diff --git a/src/post_process/m_start_up.f90 b/src/post_process/m_start_up.f90
index 301e385d3..6e8b23962 100644
--- a/src/post_process/m_start_up.f90
+++ b/src/post_process/m_start_up.f90
@@ -155,11 +155,11 @@ subroutine s_perform_time_step(t_step)
         if (proc_rank == 0) then
             if (cfl_dt) then
                 print '(" ["I3"%]  Saving "I8" of "I0"")', &
-                    int(ceiling(100d0*(real(t_step - n_start)/(n_save)))), &
+                    int(ceiling(100._wp*(real(t_step - n_start)/(n_save)))), &
                     t_step, n_save
             else
                 print '(" ["I3"%]  Saving "I8" of "I0" @ t_step = "I0"")', &
-                    int(ceiling(100d0*(real(t_step - t_step_start)/(t_step_stop - t_step_start + 1)))), &
+                    int(ceiling(100._wp*(real(t_step - t_step_start)/(t_step_stop - t_step_start + 1)))), &
                     (t_step - t_step_start)/t_step_save + 1, &
                     (t_step_stop - t_step_start)/t_step_save + 1, &
                     t_step
@@ -187,7 +187,7 @@ subroutine s_save_data(t_step, varname, pres, c, H)
 
         integer, intent(inout) :: t_step
         character(LEN=name_len), intent(inout) :: varname
-        real(kind(0d0)), intent(inout) :: pres, c, H
+        real(wp), intent(inout) :: pres, c, H
 
         integer :: i, j, k, l
 
@@ -494,12 +494,12 @@ subroutine s_save_data(t_step, varname, pres, c, H)
 
                         pres = q_prim_vf(E_idx)%sf(i, j, k)
 
-                        H = ((gamma_sf(i, j, k) + 1d0)*pres + &
+                        H = ((gamma_sf(i, j, k) + 1._wp)*pres + &
                              pi_inf_sf(i, j, k))/rho_sf(i, j, k)
 
                         call s_compute_speed_of_sound(pres, rho_sf(i, j, k), &
                                                       gamma_sf(i, j, k), pi_inf_sf(i, j, k), &
-                                                      H, adv, 0d0, 0d0, c)
+                                                      H, adv, 0._wp, 0._wp, c)
 
                         q_sf(i, j, k) = c
                     end do
diff --git a/src/post_process/p_main.fpp b/src/post_process/p_main.fpp
index 33a1729a8..ce3e0271a 100644
--- a/src/post_process/p_main.fpp
+++ b/src/post_process/p_main.fpp
@@ -26,9 +26,9 @@ program p_main
     !! Generic storage for the name(s) of the flow variable(s) that will be added
     !! to the formatted database file(s)
 
-    real(kind(0d0)) :: pres
-    real(kind(0d0)) :: c
-    real(kind(0d0)) :: H
+    real(wp) :: pres
+    real(wp) :: c
+    real(wp) :: H
 
     call s_initialize_mpi_domain()
 
diff --git a/src/pre_process/include/2dHardcodedIC.fpp b/src/pre_process/include/2dHardcodedIC.fpp
index 7d6ee9602..1149cd610 100644
--- a/src/pre_process/include/2dHardcodedIC.fpp
+++ b/src/pre_process/include/2dHardcodedIC.fpp
@@ -1,11 +1,11 @@
 #:def Hardcoded2DVariables()
 
-    real(kind(0d0)) :: eps
-    real(kind(0d0)) :: r, rmax, gam, umax, p0
+    real(wp) :: eps
+    real(wp) :: r, rmax, gam, umax, p0
 
-    real(kind(0d0)) :: rhoH, rhoL, pRef, pInt, h, lam, wl, amp, intH, alph
+    real(wp) :: rhoH, rhoL, pRef, pInt, h, lam, wl, amp, intH, alph
 
-    eps = 1e-9
+    eps = 1e-9_wp
 
 #:enddef
 
@@ -13,91 +13,91 @@
 
     select case (patch_icpp(patch_id)%hcid) ! 2D_hardcoded_ic example case
     case (200)
-        if (y_cc(j) <= (-x_cc(i)**3 + 1)**(1d0/3d0)) then
+        if (y_cc(j) <= (-x_cc(i)**3 + 1)**(1._wp/3._wp)) then
             ! Volume Fractions
             q_prim_vf(advxb)%sf(i, j, 0) = eps
-            q_prim_vf(advxe)%sf(i, j, 0) = 1d0 - eps
+            q_prim_vf(advxe)%sf(i, j, 0) = 1._wp - eps
             ! Denssities
-            q_prim_vf(contxb)%sf(i, j, 0) = eps*1000d0
-            q_prim_vf(contxe)%sf(i, j, 0) = (1d0 - eps)*1d0
+            q_prim_vf(contxb)%sf(i, j, 0) = eps*1000._wp
+            q_prim_vf(contxe)%sf(i, j, 0) = (1._wp - eps)*1._wp
             ! Pressure
-            q_prim_vf(E_idx)%sf(i, j, 0) = 1000d0
+            q_prim_vf(E_idx)%sf(i, j, 0) = 1000._wp
         end if
     case (202) ! Gresho vortex (Gouasmi et al 2022 JCP)
-        r = ((x_cc(i) - 0.5d0)**2 + (y_cc(j) - 0.5d0)**2)**0.5d0
-        rmax = 0.2
+        r = ((x_cc(i) - 0.5_wp)**2 + (y_cc(j) - 0.5_wp)**2)**0.5_wp
+        rmax = 0.2_wp
 
-        gam = 1d0 + 1d0/fluid_pp(1)%gamma
+        gam = 1._wp + 1._wp/fluid_pp(1)%gamma
         umax = 2*pi*rmax*patch_icpp(patch_id)%vel(2)
-        p0 = umax**2*(1d0/(gam*patch_icpp(patch_id)%vel(2)**2) - 0.5d0)
+        p0 = umax**2*(1._wp/(gam*patch_icpp(patch_id)%vel(2)**2) - 0.5_wp)
 
         if (r < rmax) then
-            q_prim_vf(momxb)%sf(i, j, 0) = -(y_cc(j) - 0.5d0)*umax/rmax
-            q_prim_vf(momxe)%sf(i, j, 0) = (x_cc(i) - 0.5d0)*umax/rmax
-            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2d0)
+            q_prim_vf(momxb)%sf(i, j, 0) = -(y_cc(j) - 0.5_wp)*umax/rmax
+            q_prim_vf(momxe)%sf(i, j, 0) = (x_cc(i) - 0.5_wp)*umax/rmax
+            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2._wp)
         else if (r < 2*rmax) then
-            q_prim_vf(momxb)%sf(i, j, 0) = -((y_cc(j) - 0.5d0)/r)*umax*(2d0 - r/rmax)
-            q_prim_vf(momxe)%sf(i, j, 0) = ((x_cc(i) - 0.5d0)/r)*umax*(2d0 - r/rmax)
-            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2d0 + 4*(1 - (r/rmax) + log(r/rmax)))
+            q_prim_vf(momxb)%sf(i, j, 0) = -((y_cc(j) - 0.5_wp)/r)*umax*(2._wp - r/rmax)
+            q_prim_vf(momxe)%sf(i, j, 0) = ((x_cc(i) - 0.5_wp)/r)*umax*(2._wp - r/rmax)
+            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2._wp + 4*(1 - (r/rmax) + log(r/rmax)))
         else
-            q_prim_vf(momxb)%sf(i, j, 0) = 0d0
-            q_prim_vf(momxe)%sf(i, j, 0) = 0d0
-            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*(-2 + 4*log(2.))
+            q_prim_vf(momxb)%sf(i, j, 0) = 0._wp
+            q_prim_vf(momxe)%sf(i, j, 0) = 0._wp
+            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*(-2 + 4*log(2._wp))
         end if
     case (203) ! Gresho vortex (Gouasmi et al 2022 JCP) with density correction
-        r = ((x_cc(i) - 0.5d0)**2 + (y_cc(j) - 0.5d0)**2)**0.5d0
-        rmax = 0.2
+        r = ((x_cc(i) - 0.5_wp)**2._wp + (y_cc(j) - 0.5_wp)**2)**0.5_wp
+        rmax = 0.2_wp
 
-        gam = 1d0 + 1d0/fluid_pp(1)%gamma
+        gam = 1._wp + 1._wp/fluid_pp(1)%gamma
         umax = 2*pi*rmax*patch_icpp(patch_id)%vel(2)
-        p0 = umax**2*(1d0/(gam*patch_icpp(patch_id)%vel(2)**2) - 0.5d0)
+        p0 = umax**2*(1._wp/(gam*patch_icpp(patch_id)%vel(2)**2) - 0.5_wp)
 
         if (r < rmax) then
-            q_prim_vf(momxb)%sf(i, j, 0) = -(y_cc(j) - 0.5d0)*umax/rmax
-            q_prim_vf(momxe)%sf(i, j, 0) = (x_cc(i) - 0.5d0)*umax/rmax
-            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2d0)
+            q_prim_vf(momxb)%sf(i, j, 0) = -(y_cc(j) - 0.5_wp)*umax/rmax
+            q_prim_vf(momxe)%sf(i, j, 0) = (x_cc(i) - 0.5_wp)*umax/rmax
+            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2._wp/2._wp)
         else if (r < 2*rmax) then
-            q_prim_vf(momxb)%sf(i, j, 0) = -((y_cc(j) - 0.5d0)/r)*umax*(2d0 - r/rmax)
-            q_prim_vf(momxe)%sf(i, j, 0) = ((x_cc(i) - 0.5d0)/r)*umax*(2d0 - r/rmax)
-            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2d0 + 4*(1 - (r/rmax) + log(r/rmax)))
+            q_prim_vf(momxb)%sf(i, j, 0) = -((y_cc(j) - 0.5_wp)/r)*umax*(2._wp - r/rmax)
+            q_prim_vf(momxe)%sf(i, j, 0) = ((x_cc(i) - 0.5_wp)/r)*umax*(2._wp - r/rmax)
+            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*((r/rmax)**2/2._wp + 4._wp*(1._wp - (r/rmax) + log(r/rmax)))
         else
-            q_prim_vf(momxb)%sf(i, j, 0) = 0d0
-            q_prim_vf(momxe)%sf(i, j, 0) = 0d0
-            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2*(-2 + 4*log(2.))
+            q_prim_vf(momxb)%sf(i, j, 0) = 0._wp
+            q_prim_vf(momxe)%sf(i, j, 0) = 0._wp
+            q_prim_vf(E_idx)%sf(i, j, 0) = p0 + umax**2._wp*(-2._wp + 4*log(2._wp))
         end if
 
-        q_prim_vf(contxb)%sf(i, j, 0) = q_prim_vf(E_idx)%sf(i, j, 0)**(1d0/gam)
+        q_prim_vf(contxb)%sf(i, j, 0) = q_prim_vf(E_idx)%sf(i, j, 0)**(1._wp/gam)
 
     case (204) ! Rayleigh-Taylor instability
-        rhoH = 3
-        rhoL = 1
-        pRef = 1e5
+        rhoH = 3._wp
+        rhoL = 1._wp
+        pRef = 1.e5_wp
         pInt = pRef
-        h = 0.7
-        lam = 0.2
-        wl = 2*pi/lam
-        amp = 0.05/wl
+        h = 0.7_wp
+        lam = 0.2_wp
+        wl = 2._wp*pi/lam
+        amp = 0.05_wp/wl
 
-        intH = amp*sin(2*pi*x_cc(i)/lam - pi/2) + h
+        intH = amp*sin(2._wp*pi*x_cc(i)/lam - pi/2._wp) + h
 
-        alph = 5d-1*(1 + tanh((y_cc(j) - intH)/2.5e-3))
+        alph = 0.5_wp*(1._wp + tanh((y_cc(j) - intH)/2.5e-3_wp))
 
         if (alph < eps) alph = eps
-        if (alph > 1 - eps) alph = 1 - eps
+        if (alph > 1._wp - eps) alph = 1._wp - eps
 
         if (y_cc(j) > intH) then
             q_prim_vf(advxb)%sf(i, j, 0) = alph
-            q_prim_vf(advxe)%sf(i, j, 0) = 1 - alph
+            q_prim_vf(advxe)%sf(i, j, 0) = 1._wp - alph
             q_prim_vf(contxb)%sf(i, j, 0) = alph*rhoH
-            q_prim_vf(contxe)%sf(i, j, 0) = (1 - alph)*rhoL
-            q_prim_vf(E_idx)%sf(i, j, 0) = pref + rhoH*9.81*(1.2 - y_cc(j))
+            q_prim_vf(contxe)%sf(i, j, 0) = (1._wp - alph)*rhoL
+            q_prim_vf(E_idx)%sf(i, j, 0) = pref + rhoH*9.81_wp*(1.2_wp - y_cc(j))
         else
             q_prim_vf(advxb)%sf(i, j, 0) = alph
-            q_prim_vf(advxe)%sf(i, j, 0) = 1 - alph
+            q_prim_vf(advxe)%sf(i, j, 0) = 1._wp - alph
             q_prim_vf(contxb)%sf(i, j, 0) = alph*rhoH
-            q_prim_vf(contxe)%sf(i, j, 0) = (1 - alph)*rhoL
-            pInt = pref + rhoH*9.81*(1.2 - intH)
-            q_prim_vf(E_idx)%sf(i, j, 0) = pInt + rhoL*9.81*(intH - y_cc(j))
+            q_prim_vf(contxe)%sf(i, j, 0) = (1._wp - alph)*rhoL
+            pInt = pref + rhoH*9.81_wp*(1.2_wp - intH)
+            q_prim_vf(E_idx)%sf(i, j, 0) = pInt + rhoL*9.81_wp*(intH - y_cc(j))
         end if
 
     case default
diff --git a/src/pre_process/include/3dHardcodedIC.fpp b/src/pre_process/include/3dHardcodedIC.fpp
index 3d9a4e2f1..a75476c37 100644
--- a/src/pre_process/include/3dHardcodedIC.fpp
+++ b/src/pre_process/include/3dHardcodedIC.fpp
@@ -1,46 +1,46 @@
 #:def Hardcoded3DVariables()
     ! Place any declaration of intermediate variables here
 
-    real(kind(0d0)) :: rhoH, rhoL, pRef, pInt, h, lam, wl, amp, intH, alph
+    real(wp) :: rhoH, rhoL, pRef, pInt, h, lam, wl, amp, intH, alph
 
-    real(kind(0d0)) :: eps
+    real(wp) :: eps
 
-    eps = 1e-9
+    eps = 1e-9_wp
 #:enddef
 
 #:def Hardcoded3D()
 
     select case (patch_icpp(patch_id)%hcid)
     case (300) ! Rayleigh-Taylor instability
-        rhoH = 3
-        rhoL = 1
-        pRef = 1e5
+        rhoH = 3._wp
+        rhoL = 1._wp
+        pRef = 1.e5_wp
         pInt = pRef
-        h = 0.7
-        lam = 0.2
-        wl = 2*pi/lam
-        amp = 0.025/wl
+        h = 0.7_wp
+        lam = 0.2_wp
+        wl = 2._wp*pi/lam
+        amp = 0.025_wp/wl
 
-        intH = amp*(sin(2*pi*x_cc(i)/lam - pi/2) + sin(2*pi*z_cc(k)/lam - pi/2)) + h
+        intH = amp*(sin(2._wp*pi*x_cc(i)/lam - pi/2._wp) + sin(2._wp*pi*z_cc(k)/lam - pi/2._wp)) + h
 
-        alph = 5d-1*(1 + tanh((y_cc(j) - intH)/2.5e-3))
+        alph = 5e-1_wp*(1._wp + tanh((y_cc(j) - intH)/2.5e-3_wp))
 
         if (alph < eps) alph = eps
-        if (alph > 1 - eps) alph = 1 - eps
+        if (alph > 1._wp - eps) alph = 1._wp - eps
 
         if (y_cc(j) > intH) then
             q_prim_vf(advxb)%sf(i, j, k) = alph
-            q_prim_vf(advxe)%sf(i, j, k) = 1 - alph
+            q_prim_vf(advxe)%sf(i, j, k) = 1._wp - alph
             q_prim_vf(contxb)%sf(i, j, k) = alph*rhoH
-            q_prim_vf(contxe)%sf(i, j, k) = (1 - alph)*rhoL
-            q_prim_vf(E_idx)%sf(i, j, k) = pref + rhoH*9.81*(1.2 - y_cc(j))
+            q_prim_vf(contxe)%sf(i, j, k) = (1._wp - alph)*rhoL
+            q_prim_vf(E_idx)%sf(i, j, k) = pref + rhoH*9.81_wp*(1.2_wp - y_cc(j))
         else
             q_prim_vf(advxb)%sf(i, j, k) = alph
-            q_prim_vf(advxe)%sf(i, j, k) = 1 - alph
+            q_prim_vf(advxe)%sf(i, j, k) = 1._wp - alph
             q_prim_vf(contxb)%sf(i, j, k) = alph*rhoH
-            q_prim_vf(contxe)%sf(i, j, k) = (1 - alph)*rhoL
-            pInt = pref + rhoH*9.81*(1.2 - intH)
-            q_prim_vf(E_idx)%sf(i, j, k) = pInt + rhoL*9.81*(intH - y_cc(j))
+            q_prim_vf(contxe)%sf(i, j, k) = (1._wp - alph)*rhoL
+            pInt = pref + rhoH*9.81_wp*(1.2_wp - intH)
+            q_prim_vf(E_idx)%sf(i, j, k) = pInt + rhoL*9.81_wp*(intH - y_cc(j))
         end if
 
         ! Put your variable assignments here
diff --git a/src/pre_process/m_assign_variables.fpp b/src/pre_process/m_assign_variables.fpp
index c24e0ee40..4b1e8d184 100644
--- a/src/pre_process/m_assign_variables.fpp
+++ b/src/pre_process/m_assign_variables.fpp
@@ -49,11 +49,11 @@ module m_assign_variables
         subroutine s_assign_patch_xxxxx_primitive_variables(patch_id, j, k, l, &
                                                             eta, q_prim_vf, patch_id_fp)
 
-            import :: scalar_field, sys_size, n, m, p
+            import :: scalar_field, sys_size, n, m, p, wp
 
             integer, intent(in) :: patch_id
             integer, intent(in) :: j, k, l
-            real(kind(0d0)), intent(in) :: eta
+            real(wp), intent(in) :: eta
             type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
             integer, dimension(0:m, 0:n, 0:p), intent(inout) :: patch_id_fp
 
@@ -111,18 +111,18 @@ contains
 
         integer, intent(in) :: patch_id
         integer, intent(in) :: j, k, l
-        real(kind(0d0)), intent(in) :: eta
+        real(wp), intent(in) :: eta
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
         integer, dimension(0:m, 0:n, 0:p), intent(inout) :: patch_id_fp
 
-        real(kind(0d0)) :: rho    !< density
-        real(kind(0d0)), dimension(int(E_idx - mom_idx%beg)) :: vel    !< velocity
-        real(kind(0d0)) :: pres   !< pressure
-        real(kind(0d0)) :: gamma  !< specific heat ratio function
-        real(kind(0d0)) :: x_centroid, y_centroid
-        real(kind(0d0)) :: epsilon, beta
-        real(kind(0d0)) :: Ys(1:num_species)
-        real(kind(0d0)) :: mean_molecular_weight
+        real(wp) :: rho    !< density
+        real(wp), dimension(int(E_idx - mom_idx%beg)) :: vel    !< velocity
+        real(wp) :: pres   !< pressure
+        real(wp) :: gamma  !< specific heat ratio function
+        real(wp) :: x_centroid, y_centroid
+        real(wp) :: epsilon, beta
+        real(wp) :: Ys(1:num_species)
+        real(wp) :: mean_molecular_weight
 
         integer :: smooth_patch_id
         integer :: i !< generic loop operator
@@ -135,47 +135,47 @@ contains
         ! Density
         q_prim_vf(1)%sf(j, k, l) = &
             eta*patch_icpp(patch_id)%rho &
-            + (1d0 - eta)*patch_icpp(smooth_patch_id)%rho
+            + (1._wp - eta)*patch_icpp(smooth_patch_id)%rho
 
         ! Velocity
         do i = 1, E_idx - mom_idx%beg
             q_prim_vf(i + 1)%sf(j, k, l) = &
-                1d0/q_prim_vf(1)%sf(j, k, l)* &
+                1._wp/q_prim_vf(1)%sf(j, k, l)* &
                 (eta*patch_icpp(patch_id)%rho &
                  *patch_icpp(patch_id)%vel(i) &
-                 + (1d0 - eta)*patch_icpp(smooth_patch_id)%rho &
+                 + (1._wp - eta)*patch_icpp(smooth_patch_id)%rho &
                  *patch_icpp(smooth_patch_id)%vel(i))
         end do
 
         ! Specific heat ratio function
         q_prim_vf(gamma_idx)%sf(j, k, l) = &
             eta*patch_icpp(patch_id)%gamma &
-            + (1d0 - eta)*patch_icpp(smooth_patch_id)%gamma
+            + (1._wp - eta)*patch_icpp(smooth_patch_id)%gamma
 
         ! Pressure
         q_prim_vf(E_idx)%sf(j, k, l) = &
-            1d0/q_prim_vf(gamma_idx)%sf(j, k, l)* &
+            1._wp/q_prim_vf(gamma_idx)%sf(j, k, l)* &
             (eta*patch_icpp(patch_id)%gamma &
              *patch_icpp(patch_id)%pres &
-             + (1d0 - eta)*patch_icpp(smooth_patch_id)%gamma &
+             + (1._wp - eta)*patch_icpp(smooth_patch_id)%gamma &
              *patch_icpp(smooth_patch_id)%pres)
 
         ! Liquid stiffness function
         q_prim_vf(pi_inf_idx)%sf(j, k, l) = &
             eta*patch_icpp(patch_id)%pi_inf &
-            + (1d0 - eta)*patch_icpp(smooth_patch_id)%pi_inf
+            + (1._wp - eta)*patch_icpp(smooth_patch_id)%pi_inf
 
         ! Species Concentrations
         if (chemistry) then
             block
-                real(kind(0d0)) :: sum, term
+                real(wp) :: sum, term
 
                 ! Accumulating the species concentrations
-                sum = 0d0
+                sum = 0._wp
                 do i = 1, num_species
                     term = &
                         eta*patch_icpp(patch_id)%Y(i) &
-                        + (1d0 - eta)*patch_icpp(smooth_patch_id)%Y(i)
+                        + (1._wp - eta)*patch_icpp(smooth_patch_id)%Y(i)
                     q_prim_vf(chemxb + i - 1)%sf(j, k, l) = term
                     sum = sum + term
                 end do
@@ -197,7 +197,7 @@ contains
         end if
 
         ! Updating the patch identities bookkeeping variable
-        if (1d0 - eta < 1d-16) patch_id_fp(j, k, l) = patch_id
+        if (1._wp - eta < 1e-16_wp) patch_id_fp(j, k, l) = patch_id
 
     end subroutine s_assign_patch_mixture_primitive_variables
 
@@ -212,59 +212,59 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i
-        real(kind(0d0)) :: pres_mag, loc, n_tait, B_tait, p0
-        real(kind(0d0)) :: R3bar, n0, ratio, nH, vfH, velH, rhoH, deno
+        real(wp) :: pres_mag, loc, n_tait, B_tait, p0
+        real(wp) :: R3bar, n0, ratio, nH, vfH, velH, rhoH, deno
 
         p0 = 101325
-        pres_mag = 1d-1
+        pres_mag = 1e-1_wp
         loc = x_cc(177)
         n_tait = fluid_pp(1)%gamma
         B_tait = fluid_pp(1)%pi_inf
 
-        n_tait = 1.d0/n_tait + 1.d0
-        B_tait = B_tait*(n_tait - 1d0)/n_tait
+        n_tait = 1._wp/n_tait + 1._wp
+        B_tait = B_tait*(n_tait - 1._wp)/n_tait
 
         if (j < 177) then
-            q_prim_vf(E_idx)%sf(j, k, l) = 0.5*q_prim_vf(E_idx)%sf(j, k, l)
+            q_prim_vf(E_idx)%sf(j, k, l) = 0.5_wp*q_prim_vf(E_idx)%sf(j, k, l)
         end if
 
         if (qbmm) then
             do i = 1, nb
-                q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l) = q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)*((p0 - fluid_pp(1)%pv)/(q_prim_vf(E_idx)%sf(j, k, l)*p0 - fluid_pp(1)%pv))**(1/3d0)
+                q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l) = q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)*((p0 - fluid_pp(1)%pv)/(q_prim_vf(E_idx)%sf(j, k, l)*p0 - fluid_pp(1)%pv))**(1/3._wp)
             end do
         end if
 
-        R3bar = 0d0
+        R3bar = 0._wp
 
         if (qbmm) then
             do i = 1, nb
-                R3bar = R3bar + weight(i)*0.5d0*(q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l))**3d0
-                R3bar = R3bar + weight(i)*0.5d0*(q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l))**3d0
+                R3bar = R3bar + weight(i)*0.5_wp*(q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l))**3._wp
+                R3bar = R3bar + weight(i)*0.5_wp*(q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l))**3._wp
             end do
         else
             do i = 1, nb
                 if (polytropic) then
-                    R3bar = R3bar + weight(i)*(q_prim_vf(bubxb + (i - 1)*2)%sf(j, k, l))**3d0
+                    R3bar = R3bar + weight(i)*(q_prim_vf(bubxb + (i - 1)*2)%sf(j, k, l))**3._wp
                 else
-                    R3bar = R3bar + weight(i)*(q_prim_vf(bubxb + (i - 1)*4)%sf(j, k, l))**3d0
+                    R3bar = R3bar + weight(i)*(q_prim_vf(bubxb + (i - 1)*4)%sf(j, k, l))**3._wp
                 end if
             end do
         end if
 
-        n0 = 3d0*q_prim_vf(alf_idx)%sf(j, k, l)/(4d0*pi*R3bar)
+        n0 = 3._wp*q_prim_vf(alf_idx)%sf(j, k, l)/(4._wp*pi*R3bar)
 
-        ratio = ((1d0 + B_tait)/(q_prim_vf(E_idx)%sf(j, k, l) + B_tait))**(1d0/n_tait)
+        ratio = ((1._wp + B_tait)/(q_prim_vf(E_idx)%sf(j, k, l) + B_tait))**(1._wp/n_tait)
 
-        nH = n0/((1d0 - q_prim_vf(alf_idx)%sf(j, k, l))*ratio + (4d0*pi/3d0)*n0*R3bar)
-        vfH = (4d0*pi/3d0)*nH*R3bar
-        rhoH = (1d0 - vfH)/ratio
-        deno = 1d0 - (1d0 - q_prim_vf(alf_idx)%sf(j, k, l))/rhoH
+        nH = n0/((1._wp - q_prim_vf(alf_idx)%sf(j, k, l))*ratio + (4._wp*pi/3._wp)*n0*R3bar)
+        vfH = (4._wp*pi/3._wp)*nH*R3bar
+        rhoH = (1._wp - vfH)/ratio
+        deno = 1._wp - (1._wp - q_prim_vf(alf_idx)%sf(j, k, l))/rhoH
 
-        if (deno == 0d0) then
-            velH = 0d0
+        if (deno == 0._wp) then
+            velH = 0._wp
         else
-            velH = (q_prim_vf(E_idx)%sf(j, k, l) - 1d0)/(1d0 - q_prim_vf(alf_idx)%sf(j, k, l))/deno
-            velH = dsqrt(velH)
+            velH = (q_prim_vf(E_idx)%sf(j, k, l) - 1._wp)/(1._wp - q_prim_vf(alf_idx)%sf(j, k, l))/deno
+            velH = sqrt(velH)
             velH = velH*deno
         end if
 
@@ -296,34 +296,34 @@ contains
 
         integer, intent(in) :: patch_id
         integer, intent(in) :: j, k, l
-        real(kind(0d0)), intent(in) :: eta
+        real(wp), intent(in) :: eta
         integer, dimension(0:m, 0:n, 0:p), intent(inout) :: patch_id_fp
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         ! Density, the specific heat ratio function and the liquid stiffness
         ! function, respectively, obtained from the combination of primitive
         ! variables of the current and smoothing patches
-        real(kind(0d0)) :: rho         !< density
-        real(kind(0d0)) :: gamma
-        real(kind(0d0)) :: lit_gamma   !< specific heat ratio
-        real(kind(0d0)) :: pi_inf      !< stiffness from SEOS
-        real(kind(0d0)) :: qv          !< reference energy from SEOS
-        real(kind(0d0)) :: orig_rho
-        real(kind(0d0)) :: orig_gamma
-        real(kind(0d0)) :: orig_pi_inf
-        real(kind(0d0)) :: orig_qv
-        real(kind(0d0)) :: muR, muV
-        real(kind(0d0)) :: R3bar
-
-        real(kind(0d0)), dimension(int(E_idx - mom_idx%beg)) :: vel    !< velocity
-        real(kind(0d0)) :: pres   !< pressure
-        real(kind(0d0)) :: x_centroid, y_centroid
-        real(kind(0d0)) :: epsilon, beta
-
-        real(kind(0d0)) :: Ys(1:num_species)
-        real(kind(0d0)) :: mean_molecular_weight
-
-        real(kind(0d0)), dimension(sys_size) :: orig_prim_vf !<
+        real(wp) :: rho         !< density
+        real(wp) :: gamma
+        real(wp) :: lit_gamma   !< specific heat ratio
+        real(wp) :: pi_inf      !< stiffness from SEOS
+        real(wp) :: qv          !< reference energy from SEOS
+        real(wp) :: orig_rho
+        real(wp) :: orig_gamma
+        real(wp) :: orig_pi_inf
+        real(wp) :: orig_qv
+        real(wp) :: muR, muV
+        real(wp) :: R3bar
+
+        real(wp), dimension(int(E_idx - mom_idx%beg)) :: vel    !< velocity
+        real(wp) :: pres   !< pressure
+        real(wp) :: x_centroid, y_centroid
+        real(wp) :: epsilon, beta
+
+        real(wp) :: Ys(1:num_species)
+        real(wp) :: mean_molecular_weight
+
+        real(wp), dimension(sys_size) :: orig_prim_vf !<
             !! Vector to hold original values of cell for smoothing purposes
 
         integer :: i  !< Generic loop iterator
@@ -339,13 +339,13 @@ contains
 
         if (mpp_lim .and. bubbles) then
             !adjust volume fractions, according to modeled gas void fraction
-            alf_sum%sf = 0d0
+            alf_sum%sf = 0._wp
             do i = adv_idx%beg, adv_idx%end - 1
                 alf_sum%sf = alf_sum%sf + q_prim_vf(i)%sf
             end do
 
             do i = adv_idx%beg, adv_idx%end - 1
-                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1.d0 - q_prim_vf(alf_idx)%sf) &
+                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1._wp - q_prim_vf(alf_idx)%sf) &
                                   /alf_sum%sf
             end do
         end if
@@ -367,13 +367,13 @@ contains
 
         if (mpp_lim .and. bubbles) then
             !adjust volume fractions, according to modeled gas void fraction
-            alf_sum%sf = 0d0
+            alf_sum%sf = 0._wp
             do i = adv_idx%beg, adv_idx%end - 1
                 alf_sum%sf = alf_sum%sf + q_prim_vf(i)%sf
             end do
 
             do i = adv_idx%beg, adv_idx%end - 1
-                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1.d0 - q_prim_vf(alf_idx)%sf) &
+                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1._wp - q_prim_vf(alf_idx)%sf) &
                                   /alf_sum%sf
             end do
         end if
@@ -412,13 +412,13 @@ contains
 
         if (mpp_lim .and. bubbles) then
             !adjust volume fractions, according to modeled gas void fraction
-            alf_sum%sf = 0d0
+            alf_sum%sf = 0._wp
             do i = adv_idx%beg, adv_idx%end - 1
                 alf_sum%sf = alf_sum%sf + q_prim_vf(i)%sf
             end do
 
             do i = adv_idx%beg, adv_idx%end - 1
-                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1.d0 - q_prim_vf(alf_idx)%sf) &
+                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1._wp - q_prim_vf(alf_idx)%sf) &
                                   /alf_sum%sf
             end do
         end if
@@ -431,18 +431,18 @@ contains
                 if (qbmm) then
                     ! Initialize the moment set
                     if (dist_type == 1) then
-                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1d0
+                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1._wp
                         q_prim_vf(bub_idx%fullmom(i, 1, 0))%sf(j, k, l) = muR
                         q_prim_vf(bub_idx%fullmom(i, 0, 1))%sf(j, k, l) = muV
                         q_prim_vf(bub_idx%fullmom(i, 2, 0))%sf(j, k, l) = muR**2 + sigR**2
                         q_prim_vf(bub_idx%fullmom(i, 1, 1))%sf(j, k, l) = muR*muV + rhoRV*sigR*sigV
                         q_prim_vf(bub_idx%fullmom(i, 0, 2))%sf(j, k, l) = muV**2 + sigV**2
                     else if (dist_type == 2) then
-                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1d0
-                        q_prim_vf(bub_idx%fullmom(i, 1, 0))%sf(j, k, l) = dexp((sigR**2)/2d0)*muR
+                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1._wp
+                        q_prim_vf(bub_idx%fullmom(i, 1, 0))%sf(j, k, l) = exp((sigR**2)/2._wp)*muR
                         q_prim_vf(bub_idx%fullmom(i, 0, 1))%sf(j, k, l) = muV
-                        q_prim_vf(bub_idx%fullmom(i, 2, 0))%sf(j, k, l) = dexp((sigR**2)*2d0)*(muR**2)
-                        q_prim_vf(bub_idx%fullmom(i, 1, 1))%sf(j, k, l) = dexp((sigR**2)/2d0)*muR*muV
+                        q_prim_vf(bub_idx%fullmom(i, 2, 0))%sf(j, k, l) = exp((sigR**2)*2._wp)*(muR**2)
+                        q_prim_vf(bub_idx%fullmom(i, 1, 1))%sf(j, k, l) = exp((sigR**2)/2._wp)*muR*muV
                         q_prim_vf(bub_idx%fullmom(i, 0, 2))%sf(j, k, l) = muV**2 + sigV**2
                     end if
                 else
@@ -457,9 +457,9 @@ contains
 
             if (adv_n) then
                 ! Initialize number density
-                R3bar = 0d0
+                R3bar = 0._wp
                 do i = 1, nb
-                    R3bar = R3bar + weight(i)*(q_prim_vf(bub_idx%rs(i))%sf(j, k, l))**3d0
+                    R3bar = R3bar + weight(i)*(q_prim_vf(bub_idx%rs(i))%sf(j, k, l))**3._wp
                 end do
                 q_prim_vf(n_idx)%sf(j, k, l) = 3*q_prim_vf(alf_idx)%sf(j, k, l)/(4*pi*R3bar)
             end if
@@ -479,13 +479,13 @@ contains
         ! Pressure
         q_prim_vf(E_idx)%sf(j, k, l) = &
             (eta*patch_icpp(patch_id)%pres &
-             + (1d0 - eta)*orig_prim_vf(E_idx))
+             + (1._wp - eta)*orig_prim_vf(E_idx))
 
         ! Volume fractions \alpha
         do i = adv_idx%beg, adv_idx%end
             q_prim_vf(i)%sf(j, k, l) = &
                 eta*patch_icpp(patch_id)%alpha(i - E_idx) &
-                + (1d0 - eta)*orig_prim_vf(i)
+                + (1._wp - eta)*orig_prim_vf(i)
         end do
 
         ! Elastic Shear Stress
@@ -493,19 +493,19 @@ contains
             do i = 1, (stress_idx%end - stress_idx%beg) + 1
                 q_prim_vf(i + stress_idx%beg - 1)%sf(j, k, l) = &
                     (eta*patch_icpp(patch_id)%tau_e(i) &
-                     + (1d0 - eta)*orig_prim_vf(i + stress_idx%beg - 1))
+                     + (1._wp - eta)*orig_prim_vf(i + stress_idx%beg - 1))
             end do
         end if
 
         if (mpp_lim .and. bubbles) then
             !adjust volume fractions, according to modeled gas void fraction
-            alf_sum%sf = 0d0
+            alf_sum%sf = 0._wp
             do i = adv_idx%beg, adv_idx%end - 1
                 alf_sum%sf = alf_sum%sf + q_prim_vf(i)%sf
             end do
 
             do i = adv_idx%beg, adv_idx%end - 1
-                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1.d0 - q_prim_vf(alf_idx)%sf) &
+                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1._wp - q_prim_vf(alf_idx)%sf) &
                                   /alf_sum%sf
             end do
         end if
@@ -516,13 +516,13 @@ contains
             do i = 1, cont_idx%end
                 q_prim_vf(i)%sf(j, k, l) = &
                     eta*patch_icpp(patch_id)%alpha_rho(i) &
-                    + (1d0 - eta)*orig_prim_vf(i)
+                    + (1._wp - eta)*orig_prim_vf(i)
             end do
         else
             !get mixture density from pressure via Tait EOS
             pi_inf = fluid_pp(1)%pi_inf
             gamma = fluid_pp(1)%gamma
-            lit_gamma = (1.d0 + gamma)/gamma
+            lit_gamma = (1._wp + gamma)/gamma
 
             ! \rho = (( p_l + pi_inf)/( p_ref + pi_inf))**(1/little_gam) * rhoref(1-alf)
             q_prim_vf(1)%sf(j, k, l) = &
@@ -539,26 +539,26 @@ contains
         do i = 1, E_idx - mom_idx%beg
             q_prim_vf(i + cont_idx%end)%sf(j, k, l) = &
                 (eta*patch_icpp(patch_id)%vel(i) &
-                 + (1d0 - eta)*orig_prim_vf(i + cont_idx%end))
+                 + (1._wp - eta)*orig_prim_vf(i + cont_idx%end))
         end do
 
         ! Species Concentrations
         if (chemistry) then
             block
-                real(kind(0d0)) :: sum, term
+                real(wp) :: sum, term
 
                 ! Accumulating the species concentrations
-                sum = 0d0
+                sum = 0._wp
                 do i = 1, num_species
                     term = &
                         eta*patch_icpp(patch_id)%Y(i) &
-                        + (1d0 - eta)*patch_icpp(smooth_patch_id)%Y(i)
+                        + (1._wp - eta)*patch_icpp(smooth_patch_id)%Y(i)
                     q_prim_vf(chemxb + i - 1)%sf(j, k, l) = term
                     sum = sum + term
                 end do
 
                 if (sum < verysmall) then
-                    sum = 1d0
+                    sum = 1._wp
                 end if
 
                 ! Normalizing the species concentrations
@@ -578,7 +578,7 @@ contains
         if (mixlayer_vel_profile) then
             q_prim_vf(1 + cont_idx%end)%sf(j, k, l) = &
                 (eta*patch_icpp(patch_id)%vel(1)*tanh(y_cc(k)*mixlayer_vel_coef) &
-                 + (1d0 - eta)*orig_prim_vf(1 + cont_idx%end))
+                 + (1._wp - eta)*orig_prim_vf(1 + cont_idx%end))
         end if
 
         ! Set partial pressures to mixture pressure for the 6-eqn model
@@ -596,27 +596,27 @@ contains
                 if (qbmm) then
                     ! Initialize the moment set
                     if (dist_type == 1) then
-                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1d0
+                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1._wp
                         q_prim_vf(bub_idx%fullmom(i, 1, 0))%sf(j, k, l) = muR
                         q_prim_vf(bub_idx%fullmom(i, 0, 1))%sf(j, k, l) = muV
                         q_prim_vf(bub_idx%fullmom(i, 2, 0))%sf(j, k, l) = muR**2 + sigR**2
                         q_prim_vf(bub_idx%fullmom(i, 1, 1))%sf(j, k, l) = muR*muV + rhoRV*sigR*sigV
                         q_prim_vf(bub_idx%fullmom(i, 0, 2))%sf(j, k, l) = muV**2 + sigV**2
                     else if (dist_type == 2) then
-                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1d0
-                        q_prim_vf(bub_idx%fullmom(i, 1, 0))%sf(j, k, l) = dexp((sigR**2)/2d0)*muR
+                        q_prim_vf(bub_idx%fullmom(i, 0, 0))%sf(j, k, l) = 1._wp
+                        q_prim_vf(bub_idx%fullmom(i, 1, 0))%sf(j, k, l) = exp((sigR**2)/2._wp)*muR
                         q_prim_vf(bub_idx%fullmom(i, 0, 1))%sf(j, k, l) = muV
-                        q_prim_vf(bub_idx%fullmom(i, 2, 0))%sf(j, k, l) = dexp((sigR**2)*2d0)*(muR**2)
-                        q_prim_vf(bub_idx%fullmom(i, 1, 1))%sf(j, k, l) = dexp((sigR**2)/2d0)*muR*muV
+                        q_prim_vf(bub_idx%fullmom(i, 2, 0))%sf(j, k, l) = exp((sigR**2)*2._wp)*(muR**2)
+                        q_prim_vf(bub_idx%fullmom(i, 1, 1))%sf(j, k, l) = exp((sigR**2)/2._wp)*muR*muV
                         q_prim_vf(bub_idx%fullmom(i, 0, 2))%sf(j, k, l) = muV**2 + sigV**2
                     end if
                 else
                     ! q_prim_vf(bub_idx%rs(i))%sf(j,k,l) = &
                     !     (eta * R0(i)*patch_icpp(patch_id)%r0 &
-                    !     + (1d0-eta)*orig_prim_vf(bub_idx%rs(i)))
+                    !     + (1._wp-eta)*orig_prim_vf(bub_idx%rs(i)))
                     ! q_prim_vf(bub_idx%vs(i))%sf(j,k,l) = &
                     !     (eta * V0(i)*patch_icpp(patch_id)%v0 &
-                    !     + (1d0-eta)*orig_prim_vf(bub_idx%vs(i)))
+                    !     + (1._wp-eta)*orig_prim_vf(bub_idx%vs(i)))
                     q_prim_vf(bub_idx%rs(i))%sf(j, k, l) = muR
                     q_prim_vf(bub_idx%vs(i))%sf(j, k, l) = muV
 
@@ -630,9 +630,9 @@ contains
 
             if (adv_n) then
                 ! Initialize number density
-                R3bar = 0d0
+                R3bar = 0._wp
                 do i = 1, nb
-                    R3bar = R3bar + weight(i)*(q_prim_vf(bub_idx%rs(i))%sf(j, k, l))**3d0
+                    R3bar = R3bar + weight(i)*(q_prim_vf(bub_idx%rs(i))%sf(j, k, l))**3._wp
                 end do
                 q_prim_vf(n_idx)%sf(j, k, l) = 3*q_prim_vf(alf_idx)%sf(j, k, l)/(4*pi*R3bar)
             end if
@@ -640,13 +640,13 @@ contains
 
         if (mpp_lim .and. bubbles) then
             !adjust volume fractions, according to modeled gas void fraction
-            alf_sum%sf = 0d0
+            alf_sum%sf = 0._wp
             do i = adv_idx%beg, adv_idx%end - 1
                 alf_sum%sf = alf_sum%sf + q_prim_vf(i)%sf
             end do
 
             do i = adv_idx%beg, adv_idx%end - 1
-                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1.d0 - q_prim_vf(alf_idx)%sf) &
+                q_prim_vf(i)%sf = q_prim_vf(i)%sf*(1._wp - q_prim_vf(alf_idx)%sf) &
                                   /alf_sum%sf
             end do
         end if
@@ -665,11 +665,11 @@ contains
 
         if (surface_tension) then
             q_prim_vf(c_idx)%sf(j, k, l) = eta*patch_icpp(patch_id)%cf_val + &
-                                           (1d0 - eta)*patch_icpp(smooth_patch_id)%cf_val
+                                           (1._wp - eta)*patch_icpp(smooth_patch_id)%cf_val
         end if
 
         ! Updating the patch identities bookkeeping variable
-        if (1d0 - eta < 1d-16) patch_id_fp(j, k, l) = patch_id
+        if (1._wp - eta < 1e-16_wp) patch_id_fp(j, k, l) = patch_id
 
     end subroutine s_assign_patch_species_primitive_variables
 
diff --git a/src/pre_process/m_check_ib_patches.fpp b/src/pre_process/m_check_ib_patches.fpp
index c19d321c7..d5ab5c5a7 100644
--- a/src/pre_process/m_check_ib_patches.fpp
+++ b/src/pre_process/m_check_ib_patches.fpp
@@ -94,7 +94,7 @@ contains
         call s_int_to_str(patch_id, iStr)
 
         @:PROHIBIT(n == 0 .or. p > 0 &
-            .or. patch_ib(patch_id)%radius <= 0d0 &
+            .or. patch_ib(patch_id)%radius <= 0._wp &
             .or. f_is_default(patch_ib(patch_id)%x_centroid) &
             .or. f_is_default(patch_ib(patch_id)%y_centroid), &
             'in circle IB patch '//trim(iStr))
@@ -112,10 +112,10 @@ contains
         call s_int_to_str(patch_id, iStr)
 
         @:PROHIBIT(n == 0 .or. p > 0 &
-            .or. patch_ib(patch_id)%c <= 0d0 &
-            .or. patch_ib(patch_id)%p <= 0d0 &
-            .or. patch_ib(patch_id)%t <= 0d0 &
-            .or. patch_ib(patch_id)%m <= 0d0 &
+            .or. patch_ib(patch_id)%c <= 0._wp &
+            .or. patch_ib(patch_id)%p <= 0._wp &
+            .or. patch_ib(patch_id)%t <= 0._wp &
+            .or. patch_ib(patch_id)%m <= 0._wp &
             .or. f_is_default(patch_ib(patch_id)%x_centroid) &
             .or. f_is_default(patch_ib(patch_id)%y_centroid), &
             'in airfoil IB patch '//trim(iStr))
@@ -133,10 +133,10 @@ contains
         call s_int_to_str(patch_id, iStr)
 
         @:PROHIBIT(n == 0 .or. p == 0 &
-            .or. patch_ib(patch_id)%c <= 0d0 &
-            .or. patch_ib(patch_id)%p <= 0d0 &
-            .or. patch_ib(patch_id)%t <= 0d0 &
-            .or. patch_ib(patch_id)%m <= 0d0 &
+            .or. patch_ib(patch_id)%c <= 0._wp &
+            .or. patch_ib(patch_id)%p <= 0._wp &
+            .or. patch_ib(patch_id)%t <= 0._wp &
+            .or. patch_ib(patch_id)%m <= 0._wp &
             .or. f_is_default(patch_ib(patch_id)%x_centroid) &
             .or. f_is_default(patch_ib(patch_id)%y_centroid) &
             .or. f_is_default(patch_ib(patch_id)%z_centroid) &
@@ -161,9 +161,9 @@ contains
             .or. &
             f_is_default(patch_ib(patch_id)%y_centroid) &
             .or. &
-            patch_ib(patch_id)%length_x <= 0d0 &
+            patch_ib(patch_id)%length_x <= 0._wp &
             .or. &
-            patch_ib(patch_id)%length_y <= 0d0, &
+            patch_ib(patch_id)%length_y <= 0._wp, &
             'in rectangle IB patch '//trim(iStr))
 
     end subroutine s_check_rectangle_ib_patch_geometry
@@ -186,7 +186,7 @@ contains
             .or. &
             f_is_default(patch_ib(patch_id)%z_centroid) &
             .or. &
-            patch_ib(patch_id)%radius <= 0d0, &
+            patch_ib(patch_id)%radius <= 0._wp, &
             'in sphere IB patch '//trim(iStr))
 
     end subroutine s_check_sphere_ib_patch_geometry
@@ -209,11 +209,11 @@ contains
             .or. &
             f_is_default(patch_ib(patch_id)%z_centroid) &
             .or. &
-            patch_ib(patch_id)%length_x <= 0d0 &
+            patch_ib(patch_id)%length_x <= 0._wp &
             .or. &
-            patch_ib(patch_id)%length_y <= 0d0 &
+            patch_ib(patch_id)%length_y <= 0._wp &
             .or. &
-            patch_ib(patch_id)%length_z <= 0d0, &
+            patch_ib(patch_id)%length_z <= 0._wp, &
             'in cuboid IB patch '//trim(iStr))
 
     end subroutine s_check_cuboid_ib_patch_geometry
@@ -236,23 +236,23 @@ contains
             .or. &
             f_is_default(patch_ib(patch_id)%z_centroid) &
             .or. &
-            (patch_ib(patch_id)%length_x <= 0d0 .and. &
-             patch_ib(patch_id)%length_y <= 0d0 .and. &
-             patch_ib(patch_id)%length_z <= 0d0) &
+            (patch_ib(patch_id)%length_x <= 0._wp .and. &
+             patch_ib(patch_id)%length_y <= 0._wp .and. &
+             patch_ib(patch_id)%length_z <= 0._wp) &
             .or. &
-            patch_ib(patch_id)%radius <= 0d0, &
+            patch_ib(patch_id)%radius <= 0._wp, &
             'in cylinder IB patch '//trim(iStr))
 
         @:PROHIBIT( &
-            (patch_ib(patch_id)%length_x > 0d0 .and. &
+            (patch_ib(patch_id)%length_x > 0._wp .and. &
              ((.not. f_is_default(patch_ib(patch_id)%length_y)) .or. &
               (.not. f_is_default(patch_ib(patch_id)%length_z)))) &
             .or. &
-            (patch_ib(patch_id)%length_y > 0d0 .and. &
+            (patch_ib(patch_id)%length_y > 0._wp .and. &
              ((.not. f_is_default(patch_ib(patch_id)%length_x)) .or. &
               (.not. f_is_default(patch_ib(patch_id)%length_z)))) &
             .or. &
-            (patch_ib(patch_id)%length_z > 0d0 .and. &
+            (patch_ib(patch_id)%length_z > 0._wp .and. &
              ((.not. f_is_default(patch_ib(patch_id)%length_x)) .or. &
               (.not. f_is_default(patch_ib(patch_id)%length_y)))), &
             'in cylinder IB patch '//trim(iStr))
@@ -272,11 +272,11 @@ contains
         @:PROHIBIT(patch_ib(patch_id)%model_filepath == dflt_char, &
             'Empty model file path for patch '//trim(iStr))
 
-        @:PROHIBIT(patch_ib(patch_id)%model_scale(1) <= 0d0 &
+        @:PROHIBIT(patch_ib(patch_id)%model_scale(1) <= 0._wp &
             .or. &
-            patch_ib(patch_id)%model_scale(2) <= 0d0 &
+            patch_ib(patch_id)%model_scale(2) <= 0._wp &
             .or. &
-            patch_ib(patch_id)%model_scale(3) <= 0d0, &
+            patch_ib(patch_id)%model_scale(3) <= 0._wp, &
             'Negative scale in model IB patch '//trim(iStr))
 
     end subroutine s_check_model_ib_patch_geometry
diff --git a/src/pre_process/m_check_patches.fpp b/src/pre_process/m_check_patches.fpp
index 136d4d168..2f379a1b8 100644
--- a/src/pre_process/m_check_patches.fpp
+++ b/src/pre_process/m_check_patches.fpp
@@ -155,7 +155,7 @@ contains
         call s_int_to_str(patch_id, iStr)
 
         @:PROHIBIT(n > 0, "Line segment patch "//trim(iStr)//": n must be zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "Line segment patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "Line segment patch "//trim(iStr)//": length_x must be greater than zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Line segment patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(cyl_coord, "Line segment patch "//trim(iStr)//": cyl_coord is not supported")
 
@@ -170,7 +170,7 @@ contains
 
         @:PROHIBIT(n == 0, "Circle patch "//trim(iStr)//": n must be zero")
         @:PROHIBIT(p > 0, "Circle patch "//trim(iStr)//": p must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0d0, "Circle patch "//trim(iStr)//": radius must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0._wp, "Circle patch "//trim(iStr)//": radius must be greater than zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Circle patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Circle patch "//trim(iStr)//": y_centroid must be set")
 
@@ -187,8 +187,8 @@ contains
         @:PROHIBIT(p > 0, "Rectangle patch "//trim(iStr)//": p must be zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Rectangle patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Rectangle patch "//trim(iStr)//": y_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "Rectangle patch "//trim(iStr)//": length_x must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0d0, "Rectangle patch "//trim(iStr)//": length_y must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "Rectangle patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0._wp, "Rectangle patch "//trim(iStr)//": length_y must be greater than zero")
 
     end subroutine s_check_rectangle_patch_geometry
 
@@ -220,8 +220,8 @@ contains
         @:PROHIBIT(p > 0, "Ellipse patch "//trim(iStr)//": p must be zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Ellipse patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Ellipse patch "//trim(iStr)//": y_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%radii(1) <= 0d0, "Ellipse patch "//trim(iStr)//": radii(1) must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%radii(2) <= 0d0, "Ellipse patch "//trim(iStr)//": radii(2) must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radii(1) <= 0._wp, "Ellipse patch "//trim(iStr)//": radii(1) must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radii(2) <= 0._wp, "Ellipse patch "//trim(iStr)//": radii(2) must be greater than zero")
         @:PROHIBIT(.not. f_is_default(patch_icpp(patch_id)%radii(3)), "Ellipse patch "//trim(iStr)//": radii(3) must not be set")
 
     end subroutine s_check_ellipse_patch_geometry
@@ -237,9 +237,9 @@ contains
         @:PROHIBIT(p > 0, "Taylor Green vortex patch "//trim(iStr)//": p must be zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Taylor Green vortex patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Taylor Green vortex patch "//trim(iStr)//": y_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "Taylor Green vortex patch "//trim(iStr)//": length_x must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0d0, "Taylor Green vortex patch "//trim(iStr)//": length_y must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%vel(2) <= 0d0, "Taylor Green vortex patch "//trim(iStr)//": vel(2) must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "Taylor Green vortex patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0._wp, "Taylor Green vortex patch "//trim(iStr)//": length_y must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%vel(2) <= 0._wp, "Taylor Green vortex patch "//trim(iStr)//": vel(2) must be greater than zero")
 
     end subroutine s_check_2D_TaylorGreen_vortex_patch_geometry
 
@@ -254,7 +254,7 @@ contains
         @:PROHIBIT(p > 0, "1D analytical patch "//trim(iStr)//": p must be zero")
         @:PROHIBIT(model_eqns /= 4 .and. model_eqns /= 2, "1D analytical patch "//trim(iStr)//": model_eqns must be either 4 or 2")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "1D analytical patch "//trim(iStr)//": x_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "1D analytical patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "1D analytical patch "//trim(iStr)//": length_x must be greater than zero")
 
     end subroutine s_check_1D_analytical_patch_geometry
 
@@ -269,8 +269,8 @@ contains
         @:PROHIBIT(p > 0, "2D analytical patch "//trim(iStr)//": p must be zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "2D analytical patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "2D analytical patch "//trim(iStr)//": y_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "2D analytical patch "//trim(iStr)//": length_x must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0d0, "2D analytical patch "//trim(iStr)//": length_y must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "2D analytical patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0._wp, "2D analytical patch "//trim(iStr)//": length_y must be greater than zero")
 
     end subroutine s_check_2D_analytical_patch_geometry
 
@@ -285,9 +285,9 @@ contains
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "3D analytical patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "3D analytical patch "//trim(iStr)//": y_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%z_centroid), "3D analytical patch "//trim(iStr)//": z_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "3D analytical patch "//trim(iStr)//": length_x must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0d0, "3D analytical patch "//trim(iStr)//": length_y must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_z <= 0d0, "3D analytical patch "//trim(iStr)//": length_z must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "3D analytical patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0._wp, "3D analytical patch "//trim(iStr)//": length_y must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_z <= 0._wp, "3D analytical patch "//trim(iStr)//": length_z must be greater than zero")
 
     end subroutine s_check_3D_analytical_patch_geometry
 
@@ -299,7 +299,7 @@ contains
         call s_int_to_str(patch_id, iStr)
 
         @:PROHIBIT(p == 0, "Sphere patch "//trim(iStr)//": p must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0d0, "Sphere patch "//trim(iStr)//": radius must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0._wp, "Sphere patch "//trim(iStr)//": radius must be greater than zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Sphere patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Sphere patch "//trim(iStr)//": y_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%z_centroid), "Sphere patch "//trim(iStr)//": z_centroid must be set")
@@ -314,13 +314,13 @@ contains
         call s_int_to_str(patch_id, iStr)
 
         @:PROHIBIT(p == 0, "Spherical harmonic patch "//trim(iStr)//": p must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0d0, "Spherical harmonic patch "//trim(iStr)//": radius must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0._wp, "Spherical harmonic patch "//trim(iStr)//": radius must be greater than zero")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Spherical harmonic patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Spherical harmonic patch "//trim(iStr)//": y_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%z_centroid), "Spherical harmonic patch "//trim(iStr)//": z_centroid must be set")
-        @:PROHIBIT(all(patch_icpp(patch_id)%epsilon /= (/1d0, 2d0, 3d0, 4d0, 5d0/)), &
+        @:PROHIBIT(all(patch_icpp(patch_id)%epsilon /= (/1._wp, 2._wp, 3._wp, 4._wp, 5._wp/)), &
             "Spherical harmonic patch "//trim(iStr)//": epsilon must be one of 1, 2, 3, 4, 5")
-        @:PROHIBIT(patch_icpp(patch_id)%beta < 0d0, &
+        @:PROHIBIT(patch_icpp(patch_id)%beta < 0._wp, &
             "Spherical harmonic patch "//trim(iStr)//": beta must be greater than or equal to zero")
         @:PROHIBIT(patch_icpp(patch_id)%beta > patch_icpp(patch_id)%epsilon, &
             "Spherical harmonic patch "//trim(iStr)//": beta must be less than or equal to epsilon")
@@ -339,9 +339,9 @@ contains
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Cuboid patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Cuboid patch "//trim(iStr)//": y_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%z_centroid), "Cuboid patch "//trim(iStr)//": z_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0d0, "Cuboid patch "//trim(iStr)//": length_x must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0d0, "Cuboid patch "//trim(iStr)//": length_y must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%length_z <= 0d0, "Cuboid patch "//trim(iStr)//": length_z must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_x <= 0._wp, "Cuboid patch "//trim(iStr)//": length_x must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_y <= 0._wp, "Cuboid patch "//trim(iStr)//": length_y must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%length_z <= 0._wp, "Cuboid patch "//trim(iStr)//": length_z must be greater than zero")
 
     end subroutine s_check_cuboid_patch_geometry
 
@@ -357,20 +357,20 @@ contains
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Cylinder patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Cylinder patch "//trim(iStr)//": y_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%z_centroid), "Cylinder patch "//trim(iStr)//": z_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0d0, "Cylinder patch "//trim(iStr)//": radius must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radius <= 0._wp, "Cylinder patch "//trim(iStr)//": radius must be greater than zero")
 
         ! Check if exactly one length is defined
         @:PROHIBIT(count([ &
-            patch_icpp(patch_id)%length_x > 0d0, &
-            patch_icpp(patch_id)%length_y > 0d0, &
-            patch_icpp(patch_id)%length_z > 0d0 &
+            patch_icpp(patch_id)%length_x > 0._wp, &
+            patch_icpp(patch_id)%length_y > 0._wp, &
+            patch_icpp(patch_id)%length_z > 0._wp &
             ]) /= 1, "Cylinder patch "//trim(iStr)//": Exactly one of length_x, length_y, or length_z must be defined and positive")
 
         ! Ensure the defined length is positive
         @:PROHIBIT( &
-            (.not. f_is_default(patch_icpp(patch_id)%length_x) .and. patch_icpp(patch_id)%length_x <= 0d0) .or. &
-            (.not. f_is_default(patch_icpp(patch_id)%length_y) .and. patch_icpp(patch_id)%length_y <= 0d0) .or. &
-            (.not. f_is_default(patch_icpp(patch_id)%length_z) .and. patch_icpp(patch_id)%length_z <= 0d0), &
+            (.not. f_is_default(patch_icpp(patch_id)%length_x) .and. patch_icpp(patch_id)%length_x <= 0._wp) .or. &
+            (.not. f_is_default(patch_icpp(patch_id)%length_y) .and. patch_icpp(patch_id)%length_y <= 0._wp) .or. &
+            (.not. f_is_default(patch_icpp(patch_id)%length_z) .and. patch_icpp(patch_id)%length_z <= 0._wp), &
             "Cylinder patch "//trim(iStr)//": The defined length_{} must be greater than zero")
 
     end subroutine s_check_cylinder_patch_geometry
@@ -404,9 +404,9 @@ contains
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%x_centroid), "Ellipsoid patch "//trim(iStr)//": x_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%y_centroid), "Ellipsoid patch "//trim(iStr)//": y_centroid must be set")
         @:PROHIBIT(f_is_default(patch_icpp(patch_id)%z_centroid), "Ellipsoid patch "//trim(iStr)//": z_centroid must be set")
-        @:PROHIBIT(patch_icpp(patch_id)%radii(1) <= 0d0, "Ellipsoid patch "//trim(iStr)//": radii(1) must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%radii(2) <= 0d0, "Ellipsoid patch "//trim(iStr)//": radii(2) must be greater than zero")
-        @:PROHIBIT(patch_icpp(patch_id)%radii(3) <= 0d0, "Ellipsoid patch "//trim(iStr)//": radii(3) must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radii(1) <= 0._wp, "Ellipsoid patch "//trim(iStr)//": radii(1) must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radii(2) <= 0._wp, "Ellipsoid patch "//trim(iStr)//": radii(2) must be greater than zero")
+        @:PROHIBIT(patch_icpp(patch_id)%radii(3) <= 0._wp, "Ellipsoid patch "//trim(iStr)//": radii(3) must be greater than zero")
 
     end subroutine s_check_ellipsoid_patch_geometry
 
@@ -474,7 +474,7 @@ contains
                 "Smoothen enabled. Patch "//trim(iStr)//": smooth_patch_id must be less than patch_id")
             @:PROHIBIT(patch_icpp(patch_id)%smooth_patch_id == 0, &
                 "Smoothen enabled. Patch "//trim(iStr)//": smooth_patch_id must be greater than zero")
-            @:PROHIBIT(patch_icpp(patch_id)%smooth_coeff <= 0d0, &
+            @:PROHIBIT(patch_icpp(patch_id)%smooth_coeff <= 0._wp, &
                 "Smoothen enabled. Patch "//trim(iStr)//": smooth_coeff must be greater than zero")
         else
             @:PROHIBIT(patch_icpp(patch_id)%smooth_patch_id /= patch_id, &
@@ -520,15 +520,15 @@ contains
             "Patch "//trim(iStr)//": vel(3) must not be set when p = 0")
         @:PROHIBIT(p > 0 .and. f_is_default(patch_icpp(patch_id)%vel(3)), &
             "Patch "//trim(iStr)//": vel(3) must be set when p > 0")
-        @:PROHIBIT(model_eqns == 1 .and. patch_icpp(patch_id)%rho <= 0d0, &
+        @:PROHIBIT(model_eqns == 1 .and. patch_icpp(patch_id)%rho <= 0._wp, &
             "Patch "//trim(iStr)//": rho must be greater than zero when model_eqns = 1")
-        @:PROHIBIT(model_eqns == 1 .and. patch_icpp(patch_id)%gamma <= 0d0, &
+        @:PROHIBIT(model_eqns == 1 .and. patch_icpp(patch_id)%gamma <= 0._wp, &
             "Patch "//trim(iStr)//": gamma must be greater than zero when model_eqns = 1")
-        @:PROHIBIT(model_eqns == 1 .and. patch_icpp(patch_id)%pi_inf < 0d0, &
+        @:PROHIBIT(model_eqns == 1 .and. patch_icpp(patch_id)%pi_inf < 0._wp, &
             "Patch "//trim(iStr)//": pi_inf must be greater than or equal to zero when model_eqns = 1")
         @:PROHIBIT(patch_icpp(patch_id)%geometry == 5 .and. patch_icpp(patch_id)%pi_inf > 0, &
             "Patch "//trim(iStr)//": pi_inf must be less than or equal to zero when geometry = 5")
-        @:PROHIBIT(model_eqns == 2 .and. any(patch_icpp(patch_id)%alpha_rho(1:num_fluids) < 0d0), &
+        @:PROHIBIT(model_eqns == 2 .and. any(patch_icpp(patch_id)%alpha_rho(1:num_fluids) < 0._wp), &
             "Patch "//trim(iStr)//": alpha_rho(1:num_fluids) must be greater than or equal to zero when model_eqns = 2")
 
         if (model_eqns == 2 .and. num_fluids < num_fluids_max) then
@@ -541,7 +541,7 @@ contains
         end if
 
         if (chemistry) then
-            !@:ASSERT(all(patch_icpp(patch_id)%Y(1:num_species) >=       0d0), "Patch " // trim(iStr) // ".")
+            !@:ASSERT(all(patch_icpp(patch_id)%Y(1:num_species) >=       0._wp), "Patch " // trim(iStr) // ".")
             !@:ASSERT(any(patch_icpp(patch_id)%Y(1:num_species) >  verysmall), "Patch " // trim(iStr) // ".")
         end if
 
diff --git a/src/pre_process/m_checker.fpp b/src/pre_process/m_checker.fpp
index efd1ef190..ec5600c76 100644
--- a/src/pre_process/m_checker.fpp
+++ b/src/pre_process/m_checker.fpp
@@ -87,11 +87,11 @@ contains
             "n must be positive (2D or 3D) for cylindrical coordinates")
         @:PROHIBIT(cyl_coord .and. (f_is_default(y_domain%beg) .or. f_is_default(y_domain%end)), &
             "y_domain%beg and y_domain%end must be set for n = 0 (2D cylindrical coordinates)")
-        @:PROHIBIT(cyl_coord .and. (y_domain%beg /= 0d0 .or. y_domain%end <= 0d0), &
+        @:PROHIBIT(cyl_coord .and. (y_domain%beg /= 0._wp .or. y_domain%end <= 0._wp), &
             "y_domain%beg must be 0 and y_domain%end must be positive for cylindrical coordinates")
         @:PROHIBIT(cyl_coord .and. p == 0 .and. ((.not. f_is_default(z_domain%beg)) .or. (.not. f_is_default(z_domain%end))), &
             "z_domain%beg and z_domain%end are not supported for p = 0 (2D cylindrical coordinates)")
-        @:PROHIBIT(cyl_coord .and. p > 0 .and. (z_domain%beg /= 0d0 .or. z_domain%end /= 2d0*pi), &
+        @:PROHIBIT(cyl_coord .and. p > 0 .and. (z_domain%beg /= 0._wp .or. z_domain%end /= 2._wp*pi), &
             "z_domain%beg must be 0 and z_domain%end must be 2*pi for 3D cylindrical coordinates")
 
         @:PROHIBIT(num_patches < 0)
@@ -124,11 +124,11 @@ contains
             !&< Deactivate prettify
             @:PROHIBIT(stretch_${X}$ .and. (a_${X}$ + log(cosh(a_${X}$*(${X}$_domain%beg - ${X}$_a))) &
                                                     + log(cosh(a_${X}$*(${X}$_domain%beg - ${X}$_b))) &
-                                                    - 2d0*log(cosh(0.5d0*a_${X}$*(${X}$_b - ${X}$_a)))) / a_${X}$ <= 0d0, &
+                                                    - 2._wp*log(cosh(0.5_wp*a_${X}$*(${X}$_b - ${X}$_a)))) / a_${X}$ <= 0._wp, &
                 "${X}$_domain%beg is too close to ${X}$_a and ${X}$_b for the given a_${X}$")
             @:PROHIBIT(stretch_${X}$ .and. (a_${X}$ + log(cosh(a_${X}$*(${X}$_domain%end - ${X}$_a))) &
                                                     + log(cosh(a_${X}$*(${X}$_domain%end - ${X}$_b))) &
-                                                    - 2d0*log(cosh(0.5d0*a_${X}$*(${X}$_b - ${X}$_a)))) / a_${X}$ <= 0d0, &
+                                                    - 2._wp*log(cosh(0.5_wp*a_${X}$*(${X}$_b - ${X}$_a)))) / a_${X}$ <= 0._wp, &
                 "${X}$_domain%end is too close to ${X}$_a and ${X}$_b for the given a_${X}$")
             !&>
         #:endfor
@@ -138,7 +138,7 @@ contains
         !! (qbmm, polydisperse, dist_type, rhoRV, and R0_type)
     subroutine s_check_inputs_qbmm_and_polydisperse
         @:PROHIBIT(qbmm .and. dist_type == dflt_int, "dist_type must be set if using QBMM")
-        @:PROHIBIT(qbmm .and. dist_type /= 1 .and. rhoRV > 0d0, "rhoRV cannot be used with dist_type != 1")
+        @:PROHIBIT(qbmm .and. dist_type /= 1 .and. rhoRV > 0._wp, "rhoRV cannot be used with dist_type != 1")
         @:PROHIBIT(polydisperse .and. R0_type == dflt_int, "R0 type must be set if using Polydisperse")
     end subroutine s_check_inputs_qbmm_and_polydisperse
 
diff --git a/src/pre_process/m_compute_levelset.fpp b/src/pre_process/m_compute_levelset.fpp
index db4c5f04e..a79b26c0f 100644
--- a/src/pre_process/m_compute_levelset.fpp
+++ b/src/pre_process/m_compute_levelset.fpp
@@ -27,9 +27,9 @@ module m_compute_levelset
  s_cuboid_levelset, &
  s_sphere_levelset
 
-    real(kind(0d0)) :: x_centroid, y_centroid, z_centroid
-    real(kind(0d0)) :: length_x, length_y, length_z
-    real(kind(0d0)) :: radius
+    real(wp) :: x_centroid, y_centroid, z_centroid
+    real(wp) :: length_x, length_y, length_z
+    real(wp) :: radius
 
     type(bounds_info) :: x_boundary, y_boundary, z_boundary  !<
         !! These variables combine the centroid and length parameters associated with
@@ -45,9 +45,9 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
         integer, intent(IN) :: ib_patch_id
 
-        real(kind(0d0)) :: radius, dist
-        real(kind(0d0)) :: x_centroid, y_centroid
-        real(kind(0d0)), dimension(3) :: dist_vec
+        real(wp) :: radius, dist
+        real(wp) :: x_centroid, y_centroid
+        real(wp), dimension(3) :: dist_vec
 
         integer :: i, j !< Loop index variables
 
@@ -61,7 +61,7 @@ contains
                 dist_vec(1) = x_cc(i) - x_centroid
                 dist_vec(2) = y_cc(j) - y_centroid
                 dist_vec(3) = 0
-                dist = dsqrt(sum(dist_vec**2))
+                dist = sqrt(sum(dist_vec**2))
                 levelset%sf(i, j, 0, ib_patch_id) = dist - radius
                 if (dist == 0) then
                     levelset_norm%sf(i, j, 0, ib_patch_id, :) = 0
@@ -81,16 +81,16 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
         integer, intent(IN) :: ib_patch_id
 
-        real(kind(0d0)) :: radius, dist, global_dist
+        real(wp) :: radius, dist, global_dist
         integer :: global_id
-        real(kind(0d0)) :: x_centroid, y_centroid, x_act, y_act, theta
-        real(kind(0d0)), dimension(3) :: dist_vec
+        real(wp) :: x_centroid, y_centroid, x_act, y_act, theta
+        real(wp), dimension(3) :: dist_vec
 
         integer :: i, j, k !< Loop index variables
 
         x_centroid = patch_ib(ib_patch_id)%x_centroid
         y_centroid = patch_ib(ib_patch_id)%y_centroid
-        theta = pi*patch_ib(ib_patch_id)%theta/180d0
+        theta = pi*patch_ib(ib_patch_id)%theta/180._wp
 
         do i = 0, m
             do j = 0, n
@@ -108,7 +108,7 @@ contains
                         dist_vec(1) = x_cc(i) - airfoil_grid_u(k)%x
                         dist_vec(2) = y_cc(j) - airfoil_grid_u(k)%y
                         dist_vec(3) = 0
-                        dist = dsqrt(sum(dist_vec**2))
+                        dist = sqrt(sum(dist_vec**2))
                         if (k == 1) then
                             global_dist = dist
                             global_id = k
@@ -128,7 +128,7 @@ contains
                         dist_vec(1) = x_cc(i) - airfoil_grid_l(k)%x
                         dist_vec(2) = y_cc(j) - airfoil_grid_l(k)%y
                         dist_vec(3) = 0
-                        dist = dsqrt(sum(dist_vec**2))
+                        dist = sqrt(sum(dist_vec**2))
                         if (k == 1) then
                             global_dist = dist
                             global_id = k
@@ -164,10 +164,10 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
         integer, intent(IN) :: ib_patch_id
 
-        real(kind(0d0)) :: radius, dist, dist_surf, dist_side, global_dist
+        real(wp) :: radius, dist, dist_surf, dist_side, global_dist
         integer :: global_id
-        real(kind(0d0)) :: x_centroid, y_centroid, z_centroid, lz, z_max, z_min, x_act, y_act, theta
-        real(kind(0d0)), dimension(3) :: dist_vec
+        real(wp) :: x_centroid, y_centroid, z_centroid, lz, z_max, z_min, x_act, y_act, theta
+        real(wp), dimension(3) :: dist_vec
 
         integer :: i, j, k, l !< Loop index variables
 
@@ -175,7 +175,7 @@ contains
         y_centroid = patch_ib(ib_patch_id)%y_centroid
         z_centroid = patch_ib(ib_patch_id)%z_centroid
         lz = patch_ib(ib_patch_id)%length_z
-        theta = pi*patch_ib(ib_patch_id)%theta/180d0
+        theta = pi*patch_ib(ib_patch_id)%theta/180._wp
 
         z_max = z_centroid + lz/2
         z_min = z_centroid - lz/2
@@ -197,7 +197,7 @@ contains
                             dist_vec(1) = x_cc(i) - airfoil_grid_u(k)%x
                             dist_vec(2) = y_cc(j) - airfoil_grid_u(k)%y
                             dist_vec(3) = 0
-                            dist_surf = dsqrt(sum(dist_vec**2))
+                            dist_surf = sqrt(sum(dist_vec**2))
                             if (k == 1) then
                                 global_dist = dist_surf
                                 global_id = k
@@ -217,7 +217,7 @@ contains
                             dist_vec(1) = x_cc(i) - airfoil_grid_l(k)%x
                             dist_vec(2) = y_cc(j) - airfoil_grid_l(k)%y
                             dist_vec(3) = 0
-                            dist_surf = dsqrt(sum(dist_vec**2))
+                            dist_surf = sqrt(sum(dist_vec**2))
                             if (k == 1) then
                                 global_dist = dist_surf
                                 global_id = k
@@ -266,9 +266,9 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
 
         integer :: ib_patch_id
-        real(kind(0d0)) :: top_right(2), bottom_left(2)
-        real(kind(0d0)) :: x, y, min_dist
-        real(kind(0d0)) :: side_dists(4)
+        real(wp) :: top_right(2), bottom_left(2)
+        real(wp) :: x, y, min_dist
+        real(wp) :: side_dists(4)
 
         integer :: i, j, k !< Loop index variables
         integer :: idx !< Shortest path direction indicator
@@ -310,7 +310,7 @@ contains
                     if (idx == 1) then
                         levelset%sf(i, j, 0, ib_patch_id) = side_dists(1)
                         if (side_dists(1) == 0) then
-                            levelset_norm%sf(i, j, 0, ib_patch_id, 1) = 0d0
+                            levelset_norm%sf(i, j, 0, ib_patch_id, 1) = 0._wp
                         else
                             levelset_norm%sf(i, j, 0, ib_patch_id, 1) = side_dists(1)/ &
                                                                         abs(side_dists(1))
@@ -319,7 +319,7 @@ contains
                     else if (idx == 2) then
                         levelset%sf(i, j, 0, ib_patch_id) = side_dists(2)
                         if (side_dists(2) == 0) then
-                            levelset_norm%sf(i, j, 0, ib_patch_id, 1) = 0d0
+                            levelset_norm%sf(i, j, 0, ib_patch_id, 1) = 0._wp
                         else
                             levelset_norm%sf(i, j, 0, ib_patch_id, 1) = -side_dists(2)/ &
                                                                         abs(side_dists(2))
@@ -328,7 +328,8 @@ contains
                     else if (idx == 3) then
                         levelset%sf(i, j, 0, ib_patch_id) = side_dists(3)
                         if (side_dists(3) == 0) then
-                            levelset_norm%sf(i, j, 0, ib_patch_id, 2) = 0d0
+
+                            levelset_norm%sf(i, j, 0, ib_patch_id, 2) = 0._wp
                         else
                             levelset_norm%sf(i, j, 0, ib_patch_id, 2) = side_dists(3)/ &
                                                                         abs(side_dists(3))
@@ -337,7 +338,8 @@ contains
                     else if (idx == 4) then
                         levelset%sf(i, j, 0, ib_patch_id) = side_dists(4)
                         if (side_dists(4) == 0) then
-                            levelset_norm%sf(i, j, 0, ib_patch_id, 2) = 0d0
+
+                            levelset_norm%sf(i, j, 0, ib_patch_id, 2) = 0._wp
                         else
                             levelset_norm%sf(i, j, 0, ib_patch_id, 2) = -side_dists(4)/ &
                                                                         abs(side_dists(4))
@@ -358,9 +360,9 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
 
         integer, intent(IN) :: ib_patch_id
-        real(kind(0d0)) :: Right, Left, Bottom, Top, Front, Back
-        real(kind(0d0)) :: x, y, z, min_dist
-        real(kind(0d0)) :: side_dists(6)
+        real(wp) :: Right, Left, Bottom, Top, Front, Back
+        real(wp) :: x, y, z, min_dist
+        real(wp) :: side_dists(6)
 
         integer :: i, j, k !< Loop index variables
 
@@ -405,7 +407,7 @@ contains
                         if (min_dist == abs(side_dists(1))) then
                             levelset%sf(i, j, k, ib_patch_id) = side_dists(1)
                             if (side_dists(1) == 0) then
-                                levelset_norm%sf(i, j, k, ib_patch_id, 1) = 0d0
+                                levelset_norm%sf(i, j, k, ib_patch_id, 1) = 0._wp
                             else
                                 levelset_norm%sf(i, j, k, ib_patch_id, 1) = side_dists(1)/ &
                                                                             abs(side_dists(1))
@@ -414,7 +416,7 @@ contains
                         else if (min_dist == abs(side_dists(2))) then
                             levelset%sf(i, j, k, ib_patch_id) = side_dists(2)
                             if (side_dists(2) == 0) then
-                                levelset_norm%sf(i, j, k, ib_patch_id, 1) = 0d0
+                                levelset_norm%sf(i, j, k, ib_patch_id, 1) = 0._wp
                             else
                                 levelset_norm%sf(i, j, k, ib_patch_id, 1) = -side_dists(2)/ &
                                                                             abs(side_dists(2))
@@ -423,7 +425,7 @@ contains
                         else if (min_dist == abs(side_dists(3))) then
                             levelset%sf(i, j, k, ib_patch_id) = side_dists(3)
                             if (side_dists(3) == 0) then
-                                levelset_norm%sf(i, j, k, ib_patch_id, 2) = 0d0
+                                levelset_norm%sf(i, j, k, ib_patch_id, 2) = 0._wp
                             else
                                 levelset_norm%sf(i, j, k, ib_patch_id, 2) = side_dists(3)/ &
                                                                             abs(side_dists(3))
@@ -432,7 +434,7 @@ contains
                         else if (min_dist == abs(side_dists(4))) then
                             levelset%sf(i, j, k, ib_patch_id) = side_dists(4)
                             if (side_dists(4) == 0) then
-                                levelset_norm%sf(i, j, k, ib_patch_id, 2) = 0d0
+                                levelset_norm%sf(i, j, k, ib_patch_id, 2) = 0._wp
                             else
                                 levelset_norm%sf(i, j, k, ib_patch_id, 2) = -side_dists(4)/ &
                                                                             abs(side_dists(4))
@@ -441,7 +443,7 @@ contains
                         else if (min_dist == abs(side_dists(5))) then
                             levelset%sf(i, j, k, ib_patch_id) = side_dists(5)
                             if (side_dists(5) == 0) then
-                                levelset_norm%sf(i, j, k, ib_patch_id, 3) = 0d0
+                                levelset_norm%sf(i, j, k, ib_patch_id, 3) = 0._wp
                             else
                                 levelset_norm%sf(i, j, k, ib_patch_id, 3) = side_dists(5)/ &
                                                                             abs(side_dists(5))
@@ -450,7 +452,7 @@ contains
                         else if (min_dist == abs(side_dists(6))) then
                             levelset%sf(i, j, k, ib_patch_id) = side_dists(6)
                             if (side_dists(6) == 0) then
-                                levelset_norm%sf(i, j, k, ib_patch_id, 3) = 0d0
+                                levelset_norm%sf(i, j, k, ib_patch_id, 3) = 0._wp
                             else
                                 levelset_norm%sf(i, j, k, ib_patch_id, 3) = -side_dists(6)/ &
                                                                             abs(side_dists(6))
@@ -472,9 +474,9 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
         integer, intent(IN) :: ib_patch_id
 
-        real(kind(0d0)) :: radius, dist
-        real(kind(0d0)) :: x_centroid, y_centroid, z_centroid
-        real(kind(0d0)), dimension(3) :: dist_vec
+        real(wp) :: radius, dist
+        real(wp) :: x_centroid, y_centroid, z_centroid
+        real(wp), dimension(3) :: dist_vec
 
         integer :: i, j, k !< Loop index variables
 
@@ -489,7 +491,7 @@ contains
                     dist_vec(1) = x_cc(i) - x_centroid
                     dist_vec(2) = y_cc(j) - y_centroid
                     dist_vec(3) = z_cc(k) - z_centroid
-                    dist = dsqrt(sum(dist_vec**2))
+                    dist = sqrt(sum(dist_vec**2))
                     levelset%sf(i, j, k, ib_patch_id) = dist - radius
                     if (dist == 0) then
                         levelset_norm%sf(i, j, k, ib_patch_id, :) = (/1, 0, 0/)
@@ -509,11 +511,11 @@ contains
         type(levelset_norm_field), intent(INOUT) :: levelset_norm
         integer, intent(IN) :: ib_patch_id
 
-        real(kind(0d0)) :: radius, dist
-        real(kind(0d0)) :: x_centroid, y_centroid, z_centroid
-        real(kind(0d0)) :: length_x, length_y, length_z
-        real(kind(0d0)), dimension(3) :: pos_vec, centroid_vec, dist_vec, dist_sides_vec, dist_surface_vec
-        real(kind(0d0)) :: dist_side, dist_surface, side_pos
+        real(wp) :: radius, dist
+        real(wp) :: x_centroid, y_centroid, z_centroid
+        real(wp) :: length_x, length_y, length_z
+        real(wp), dimension(3) :: pos_vec, centroid_vec, dist_vec, dist_sides_vec, dist_surface_vec
+        real(wp) :: dist_side, dist_surface, side_pos
         type(bounds_info) :: boundary
         integer :: i, j, k !< Loop index variables
 
@@ -525,19 +527,19 @@ contains
         length_y = patch_ib(ib_patch_id)%length_y
         length_z = patch_ib(ib_patch_id)%length_z
 
-        if (length_x /= 0d0) then
-            boundary%beg = x_centroid - 0.5*length_x
-            boundary%end = x_centroid + 0.5*length_x
+        if (length_x /= 0._wp) then
+            boundary%beg = x_centroid - 0.5_wp*length_x
+            boundary%end = x_centroid + 0.5_wp*length_x
             dist_sides_vec = (/1, 0, 0/)
             dist_surface_vec = (/0, 1, 1/)
-        else if (length_y /= 0d0) then
-            boundary%beg = y_centroid - 0.5*length_y
-            boundary%end = y_centroid + 0.5*length_y
+        else if (length_y /= 0._wp) then
+            boundary%beg = y_centroid - 0.5_wp*length_y
+            boundary%end = y_centroid + 0.5_wp*length_y
             dist_sides_vec = (/0, 1, 0/)
             dist_surface_vec = (/1, 0, 1/)
-        else if (length_z /= 0d0) then
-            boundary%beg = z_centroid - 0.5*length_z
-            boundary%end = z_centroid + 0.5*length_z
+        else if (length_z /= 0._wp) then
+            boundary%beg = z_centroid - 0.5_wp*length_z
+            boundary%end = z_centroid + 0.5_wp*length_z
             dist_sides_vec = (/0, 0, 1/)
             dist_surface_vec = (/1, 1, 0/)
         end if
diff --git a/src/pre_process/m_data_output.fpp b/src/pre_process/m_data_output.fpp
index 8c6147ade..616434481 100644
--- a/src/pre_process/m_data_output.fpp
+++ b/src/pre_process/m_data_output.fpp
@@ -114,7 +114,7 @@ contains
         character(LEN=3) :: status
 
         character(LEN= &
-                  int(floor(log10(real(sys_size, kind(0d0))))) + 1) :: file_num !< Used to store
+                  int(floor(log10(real(sys_size, wp)))) + 1) :: file_num !< Used to store
             !! the number, in character form, of the currently
             !! manipulated conservative variable data file
 
@@ -124,16 +124,16 @@ contains
         integer :: i, j, k, l, r, c, dir !< Generic loop iterator
         integer :: t_step
 
-        real(kind(0d0)), dimension(nb) :: nRtmp         !< Temporary bubble concentration
-        real(kind(0d0)) :: nbub                         !< Temporary bubble number density
-        real(kind(0d0)) :: gamma, lit_gamma, pi_inf, qv !< Temporary EOS params
-        real(kind(0d0)) :: rho                          !< Temporary density
-        real(kind(0d0)) :: pres, Temp                         !< Temporary pressure
+        real(wp), dimension(nb) :: nRtmp         !< Temporary bubble concentration
+        real(wp) :: nbub                         !< Temporary bubble number density
+        real(wp) :: gamma, lit_gamma, pi_inf, qv !< Temporary EOS params
+        real(wp) :: rho                          !< Temporary density
+        real(wp) :: pres, Temp                         !< Temporary pressure
 
-        real(kind(0d0)) :: nR3
-        real(kind(0d0)) :: ntmp
+        real(wp) :: nR3
+        real(wp) :: ntmp
 
-        real(kind(0d0)) :: rhoYks(1:num_species) !< Temporary species mass fractions
+        real(wp) :: rhoYks(1:num_species) !< Temporary species mass fractions
 
         t_step = 0
 
@@ -252,7 +252,7 @@ contains
         ! ==================================================================
 
         gamma = fluid_pp(1)%gamma
-        lit_gamma = 1d0/fluid_pp(1)%gamma + 1d0
+        lit_gamma = 1._wp/fluid_pp(1)%gamma + 1._wp
         pi_inf = fluid_pp(1)%pi_inf
         qv = fluid_pp(1)%qv
 
@@ -288,7 +288,7 @@ contains
 
                         call s_convert_to_mixture_variables(q_cons_vf, j, 0, 0, rho, gamma, pi_inf, qv)
 
-                        lit_gamma = 1d0/gamma + 1d0
+                        lit_gamma = 1._wp/gamma + 1._wp
 
                         if ((i >= chemxb) .and. (i <= chemxe)) then
                             write (2, FMT) x_cb(j), q_cons_vf(i)%sf(j, 0, 0)/rho
@@ -309,7 +309,7 @@ contains
                             call s_compute_pressure( &
                                 q_cons_vf(E_idx)%sf(j, 0, 0), &
                                 q_cons_vf(alf_idx)%sf(j, 0, 0), &
-                                0.5d0*(q_cons_vf(mom_idx%beg)%sf(j, 0, 0)**2.d0)/rho, &
+                                0.5_wp*(q_cons_vf(mom_idx%beg)%sf(j, 0, 0)**2._wp)/rho, &
                                 pi_inf, gamma, rho, qv, rhoYks, pres, Temp)
                             write (2, FMT) x_cb(j), pres
                         else if ((i >= bub_idx%beg) .and. (i <= bub_idx%end) .and. bubbles) then
@@ -603,8 +603,8 @@ contains
             m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
             n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
             p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-            WP_MOK = int(8d0, MPI_OFFSET_KIND)
-            MOK = int(1d0, MPI_OFFSET_KIND)
+            WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+            MOK = int(1._wp, MPI_OFFSET_KIND)
             str_MOK = int(name_len, MPI_OFFSET_KIND)
             NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -614,7 +614,7 @@ contains
                     var_MOK = int(i, MPI_OFFSET_KIND)
 
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
                 !Additional variables pb and mv for non-polytropic qbmm
                 if (qbmm .and. .not. polytropic) then
@@ -622,7 +622,7 @@ contains
                         var_MOK = int(i, MPI_OFFSET_KIND)
 
                         call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                                MPI_DOUBLE_PRECISION, status, ierr)
+                                                mpi_p, status, ierr)
                     end do
                 end if
             else
@@ -631,7 +631,7 @@ contains
                     var_MOK = int(i, MPI_OFFSET_KIND)
 
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
             end if
 
@@ -667,8 +667,8 @@ contains
             m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
             n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
             p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-            WP_MOK = int(8d0, MPI_OFFSET_KIND)
-            MOK = int(1d0, MPI_OFFSET_KIND)
+            WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+            MOK = int(1._wp, MPI_OFFSET_KIND)
             str_MOK = int(name_len, MPI_OFFSET_KIND)
             NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -680,10 +680,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
                 !Additional variables pb and mv for non-polytropic qbmm
                 if (qbmm .and. .not. polytropic) then
@@ -693,10 +693,10 @@ contains
                         ! Initial displacement to skip at beginning of file
                         disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                                MPI_DOUBLE_PRECISION, status, ierr)
+                                                mpi_p, status, ierr)
                     end do
                 end if
             else
@@ -707,10 +707,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
             end if
 
@@ -752,10 +752,10 @@ contains
             ! Initial displacement to skip at beginning of file
             disp = 0
 
-            call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_levelset_DATA%view, &
+            call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_levelset_DATA%view, &
                                    'native', mpi_info_int, ierr)
             call MPI_FILE_WRITE_ALL(ifile, MPI_IO_levelset_DATA%var%sf, data_size*num_ibs, &
-                                    MPI_DOUBLE_PRECISION, status, ierr)
+                                    mpi_p, status, ierr)
 
             call MPI_FILE_CLOSE(ifile, ierr)
 
@@ -772,10 +772,10 @@ contains
             ! Initial displacement to skip at beginning of file
             disp = 0
 
-            call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_levelsetnorm_DATA%view, &
+            call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_levelsetnorm_DATA%view, &
                                    'native', mpi_info_int, ierr)
             call MPI_FILE_WRITE_ALL(ifile, MPI_IO_levelsetnorm_DATA%var%sf, data_size*num_ibs*3, &
-                                    MPI_DOUBLE_PRECISION, status, ierr)
+                                    mpi_p, status, ierr)
 
             call MPI_FILE_CLOSE(ifile, ierr)
         end if
@@ -798,10 +798,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = 0
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_airfoil_IB_DATA%view(1), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_airfoil_IB_DATA%view(1), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_airfoil_IB_DATA%var(1:Np), 3*Np, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
 
                     call MPI_FILE_CLOSE(ifile, ierr)
 
@@ -817,10 +817,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = 0
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_airfoil_IB_DATA%view(2), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_airfoil_IB_DATA%view(2), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_airfoil_IB_DATA%var(Np + 1:2*Np), 3*Np, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
 
                     call MPI_FILE_CLOSE(ifile, ierr)
                 end if
diff --git a/src/pre_process/m_global_parameters.fpp b/src/pre_process/m_global_parameters.fpp
index 7d1ad9a39..215bda634 100644
--- a/src/pre_process/m_global_parameters.fpp
+++ b/src/pre_process/m_global_parameters.fpp
@@ -53,13 +53,13 @@ module m_global_parameters
     logical :: cyl_coord
     integer :: grid_geometry !< Cylindrical coordinates (either axisymmetric or full 3D)
 
-    real(kind(0d0)), allocatable, dimension(:) :: x_cc, y_cc, z_cc !<
+    real(wp), allocatable, dimension(:) :: x_cc, y_cc, z_cc !<
     !! Locations of cell-centers (cc) in x-, y- and z-directions, respectively
 
-    real(kind(0d0)), allocatable, dimension(:) :: x_cb, y_cb, z_cb !<
+    real(wp), allocatable, dimension(:) :: x_cb, y_cb, z_cb !<
     !! Locations of cell-boundaries (cb) in x-, y- and z-directions, respectively
 
-    real(kind(0d0)) :: dx, dy, dz !<
+    real(wp) :: dx, dy, dz !<
     !! Minimum cell-widths in the x-, y- and z-coordinate directions
 
     type(bounds_info) :: x_domain, y_domain, z_domain !<
@@ -72,10 +72,10 @@ module m_global_parameters
     ! directions. The "a" parameters are a measure of the rate at which the grid
     ! is stretched while the remaining parameters are indicative of the location
     ! on the grid at which the stretching begins.
-    real(kind(0d0)) :: a_x, a_y, a_z
+    real(wp) :: a_x, a_y, a_z
     integer :: loops_x, loops_y, loops_z
-    real(kind(0d0)) :: x_a, y_a, z_a
-    real(kind(0d0)) :: x_b, y_b, z_b
+    real(wp) :: x_a, y_a, z_a
+    real(wp) :: x_b, y_b, z_b
 
     ! ==========================================================================
 
@@ -83,8 +83,8 @@ module m_global_parameters
     integer :: model_eqns            !< Multicomponent flow model
     logical :: relax                 !< activate phase change
     integer :: relax_model           !< Relax Model
-    real(kind(0d0)) :: palpha_eps    !< trigger parameter for the p relaxation procedure, phase change model
-    real(kind(0d0)) :: ptgalpha_eps  !< trigger parameter for the pTg relaxation procedure, phase change model
+    real(wp) :: palpha_eps    !< trigger parameter for the p relaxation procedure, phase change model
+    real(wp) :: ptgalpha_eps  !< trigger parameter for the pTg relaxation procedure, phase change model
     integer :: num_fluids            !< Number of different fluids present in the flow
     logical :: mpp_lim               !< Alpha limiter
     integer :: sys_size              !< Number of unknowns in the system of equations
@@ -125,19 +125,19 @@ module m_global_parameters
     integer :: precision !< Precision of output files
 
     logical :: mixlayer_vel_profile !< Set hyperbolic tangent streamwise velocity profile
-    real(kind(0d0)) :: mixlayer_vel_coef !< Coefficient for the hyperbolic tangent streamwise velocity profile
-    real(kind(0d0)) :: mixlayer_domain !< Domain for the hyperbolic tangent streamwise velocity profile
+    real(wp) :: mixlayer_vel_coef !< Coefficient for the hyperbolic tangent streamwise velocity profile
+    real(wp) :: mixlayer_domain !< Domain for the hyperbolic tangent streamwise velocity profile
     logical :: mixlayer_perturb !< Superimpose instability waves to surrounding fluid flow
 
-    real(kind(0d0)) :: pi_fac !< Factor for artificial pi_inf
+    real(wp) :: pi_fac !< Factor for artificial pi_inf
 
     ! Perturb density of surrounding air so as to break symmetry of grid
     logical :: perturb_flow
     integer :: perturb_flow_fluid   !< Fluid to be perturbed with perturb_flow flag
-    real(kind(0d0)) :: perturb_flow_mag   !< Magnitude of perturbation with perturb_flow flag
+    real(wp) :: perturb_flow_mag   !< Magnitude of perturbation with perturb_flow flag
     logical :: perturb_sph
     integer :: perturb_sph_fluid    !< Fluid to be perturbed with perturb_sph flag
-    real(kind(0d0)), dimension(num_fluids_max) :: fluid_rho
+    real(wp), dimension(num_fluids_max) :: fluid_rho
 
     integer, allocatable, dimension(:) :: proc_coords !<
     !! Processor coordinates in MPI_CART_COMM
@@ -180,18 +180,18 @@ module m_global_parameters
 
     ! ==========================================================================
 
-    real(kind(0d0)) :: rhoref, pref !< Reference parameters for Tait EOS
+    real(wp) :: rhoref, pref !< Reference parameters for Tait EOS
 
     !> @name Bubble modeling
     !> @{
     integer :: nb
-    real(kind(0d0)) :: R0ref
-    real(kind(0d0)) :: Ca, Web, Re_inv
-    real(kind(0d0)), dimension(:), allocatable :: weight, R0, V0
+    real(wp) :: R0ref
+    real(wp) :: Ca, Web, Re_inv
+    real(wp), dimension(:), allocatable :: weight, R0, V0
     logical :: bubbles
     logical :: qbmm      !< Quadrature moment method
     integer :: nmom  !< Number of carried moments
-    real(kind(0d0)) :: sigR, sigV, rhoRV !< standard deviations in R/V
+    real(wp) :: sigR, sigV, rhoRV !< standard deviations in R/V
     logical :: adv_n !< Solve the number density equation and compute alpha from number density
     !> @}
 
@@ -217,19 +217,19 @@ module m_global_parameters
     logical :: polytropic
     logical :: polydisperse
     integer :: thermal  !1 = adiabatic, 2 = isotherm, 3 = transfer
-    real(kind(0d0)) :: R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, pv, M_n, M_v
-    real(kind(0d0)), dimension(:), allocatable :: k_n, k_v, pb0, mass_n0, mass_v0, Pe_T
-    real(kind(0d0)), dimension(:), allocatable :: Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN
-    real(kind(0d0)) :: mul0, ss, gamma_v, mu_v
-    real(kind(0d0)) :: gamma_m, gamma_n, mu_n
-    real(kind(0d0)) :: poly_sigma
+    real(wp) :: R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, pv, M_n, M_v
+    real(wp), dimension(:), allocatable :: k_n, k_v, pb0, mass_n0, mass_v0, Pe_T
+    real(wp), dimension(:), allocatable :: Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN
+    real(wp) :: mul0, ss, gamma_v, mu_v
+    real(wp) :: gamma_m, gamma_n, mu_n
+    real(wp) :: poly_sigma
     integer :: dist_type !1 = binormal, 2 = lognormal-normal
     integer :: R0_type   !1 = simpson
     !> @}
 
     !> @name Surface Tension Modeling
     !> @{
-    real(kind(0d0)) :: sigma
+    real(wp) :: sigma
     logical :: surface_tension
     !> @}
 
@@ -316,8 +316,8 @@ contains
 
         #:for DIM in ['x', 'y', 'z']
             #:for DIR in [1, 2, 3]
-                bc_${DIM}$%vb${DIR}$ = 0d0
-                bc_${DIM}$%ve${DIR}$ = 0d0
+                bc_${DIM}$%vb${DIR}$ = 0._wp
+                bc_${DIM}$%ve${DIR}$ = 0._wp
             #:endfor
         #:endfor
 
@@ -325,8 +325,8 @@ contains
         file_per_process = .false.
         precision = 2
         mixlayer_vel_profile = .false.
-        mixlayer_vel_coef = 1d0
-        mixlayer_domain = 1d0
+        mixlayer_vel_coef = 1._wp
+        mixlayer_domain = 1._wp
         mixlayer_perturb = .false.
         perturb_flow = .false.
         perturb_flow_fluid = dflt_int
@@ -340,8 +340,8 @@ contains
 
         do i = 1, num_patches_max
             patch_icpp(i)%geometry = dflt_int
-            patch_icpp(i)%model_scale(:) = 1d0
-            patch_icpp(i)%model_translate(:) = 0d0
+            patch_icpp(i)%model_scale(:) = 1._wp
+            patch_icpp(i)%model_translate(:) = 0._wp
             patch_icpp(i)%model_filepath(:) = dflt_char
             patch_icpp(i)%model_spc = num_ray
             patch_icpp(i)%model_threshold = ray_tracing_threshold
@@ -368,10 +368,10 @@ contains
             patch_icpp(i)%alpha = dflt_real
             patch_icpp(i)%gamma = dflt_real
             patch_icpp(i)%pi_inf = dflt_real
-            patch_icpp(i)%cv = 0d0
-            patch_icpp(i)%qv = 0d0
-            patch_icpp(i)%qvp = 0d0
-            patch_icpp(i)%tau_e = 0d0
+            patch_icpp(i)%cv = 0._wp
+            patch_icpp(i)%qv = 0._wp
+            patch_icpp(i)%qvp = 0._wp
+            patch_icpp(i)%tau_e = 0._wp
             !should get all of r0's and v0's
             patch_icpp(i)%r0 = dflt_real
             patch_icpp(i)%v0 = dflt_real
@@ -382,7 +382,7 @@ contains
             patch_icpp(i)%hcid = dflt_int
 
             if (chemistry) then
-                patch_icpp(i)%Y(:) = 0d0
+                patch_icpp(i)%Y(:) = 0._wp
             end if
         end do
 
@@ -411,7 +411,7 @@ contains
         nmom = 1
         sigR = dflt_real
         sigV = dflt_real
-        rhoRV = 0d0
+        rhoRV = 0._wp
         dist_type = dflt_int
         R0_type = dflt_int
 
@@ -424,7 +424,7 @@ contains
 
         ! surface tension modeling
         sigma = dflt_real
-        pi_fac = 1d0
+        pi_fac = 1._wp
 
         ! Immersed Boundaries
         ib = .false.
@@ -447,9 +447,9 @@ contains
             patch_ib(i)%slip = .false.
 
             ! Proper default values for translating STL models
-            patch_ib(i)%model_scale(:) = 1d0
-            patch_ib(i)%model_translate(:) = 0d0
-            patch_ib(i)%model_rotate(:) = 0d0
+            patch_ib(i)%model_scale(:) = 1._wp
+            patch_ib(i)%model_translate(:) = 0._wp
+            patch_ib(i)%model_rotate(:) = 0._wp
             patch_ib(i)%model_filepath(:) = dflt_char
             patch_ib(i)%model_spc = num_ray
             patch_ib(i)%model_threshold = ray_tracing_threshold
@@ -466,10 +466,10 @@ contains
             fluid_pp(i)%M_v = dflt_real
             fluid_pp(i)%mu_v = dflt_real
             fluid_pp(i)%k_v = dflt_real
-            fluid_pp(i)%cv = 0d0
-            fluid_pp(i)%qv = 0d0
-            fluid_pp(i)%qvp = 0d0
-            fluid_pp(i)%G = 0d0
+            fluid_pp(i)%cv = 0._wp
+            fluid_pp(i)%qv = 0._wp
+            fluid_pp(i)%qvp = 0._wp
+            fluid_pp(i)%G = 0._wp
         end do
 
     end subroutine s_assign_default_values_to_user_inputs
@@ -588,11 +588,11 @@ contains
                 end if
 
                 if (nb == 1) then
-                    weight(:) = 1d0
-                    R0(:) = 1d0
-                    V0(:) = 1d0
+                    weight(:) = 1._wp
+                    R0(:) = 1._wp
+                    V0(:) = 1._wp
                 else if (nb > 1) then
-                    V0(:) = 1d0
+                    V0(:) = 1._wp
                     !R0 and weight initialized in s_simpson
                 else
                     stop 'Invalid value of nb'
@@ -601,8 +601,8 @@ contains
                 !Initialize pref,rhoref for polytropic qbmm (done in s_initialize_nonpoly for non-polytropic)
                 if (.not. qbmm) then
                     if (polytropic) then
-                        rhoref = 1.d0
-                        pref = 1.d0
+                        rhoref = 1._wp
+                        pref = 1._wp
                     end if
                 end if
 
@@ -613,9 +613,9 @@ contains
                         if ((f_is_default(Web))) then
                             pb0 = pref
                             pb0 = pb0/pref
-                            pref = 1d0
+                            pref = 1._wp
                         end if
-                        rhoref = 1d0
+                        rhoref = 1._wp
                     end if
                 end if
             end if
@@ -698,18 +698,18 @@ contains
                 end do
 
                 if (nb == 1) then
-                    weight(:) = 1d0
-                    R0(:) = 1d0
-                    V0(:) = 0d0
+                    weight(:) = 1._wp
+                    R0(:) = 1._wp
+                    V0(:) = 0._wp
                 else if (nb > 1) then
-                    V0(:) = 1d0
+                    V0(:) = 1._wp
                 else
                     stop 'Invalid value of nb'
                 end if
 
                 if (polytropic) then
-                    rhoref = 1.d0
-                    pref = 1.d0
+                    rhoref = 1._wp
+                    pref = 1._wp
                 end if
 
             end if
diff --git a/src/pre_process/m_grid.f90 b/src/pre_process/m_grid.f90
index 84fdb14f4..48491eaff 100644
--- a/src/pre_process/m_grid.f90
+++ b/src/pre_process/m_grid.f90
@@ -58,14 +58,14 @@ subroutine s_generate_serial_grid
 
         ! Generic loop iterator
         integer :: i, j             !< generic loop operators
-        real(kind(0d0)) :: length   !< domain lengths
+        real(wp) :: length   !< domain lengths
 
         ! Grid Generation in the x-direction ===============================
-        dx = (x_domain%end - x_domain%beg)/real(m + 1, kind(0d0))
+        dx = (x_domain%end - x_domain%beg)/real(m + 1, wp)
 
         do i = 0, m
-            x_cc(i) = x_domain%beg + 5d-1*dx*real(2*i + 1, kind(0d0))
-            x_cb(i - 1) = x_domain%beg + dx*real(i, kind(0d0))
+            x_cc(i) = x_domain%beg + 5e-1_wp*dx*real(2*i + 1, wp)
+            x_cb(i - 1) = x_domain%beg + dx*real(i, wp)
         end do
 
         x_cb(m) = x_domain%end
@@ -82,12 +82,12 @@ subroutine s_generate_serial_grid
                     x_cb(i) = x_cb(i)/a_x* &
                               (a_x + log(cosh(a_x*(x_cb(i) - x_a))) &
                                + log(cosh(a_x*(x_cb(i) - x_b))) &
-                               - 2d0*log(cosh(a_x*(x_b - x_a)/2d0)))
+                               - 2._wp*log(cosh(a_x*(x_b - x_a)/2._wp)))
                 end do
             end do
             x_cb = x_cb*length
 
-            x_cc = (x_cb(0:m) + x_cb(-1:m - 1))/2d0
+            x_cc = (x_cb(0:m) + x_cb(-1:m - 1))/2._wp
 
             dx = minval(x_cb(0:m) - x_cb(-1:m - 1))
             print *, 'Stretched grid: min/max x grid: ', minval(x_cc(:)), maxval(x_cc(:))
@@ -99,26 +99,26 @@ subroutine s_generate_serial_grid
         ! Grid Generation in the y-direction ===============================
         if (n == 0) return
 
-        if (grid_geometry == 2 .and. y_domain%beg == 0.0d0) then
+        if (grid_geometry == 2 .and. y_domain%beg == 0.0_wp) then
             !IF (grid_geometry == 2) THEN
 
-            dy = (y_domain%end - y_domain%beg)/real(2*n + 1, kind(0d0))
+            dy = (y_domain%end - y_domain%beg)/real(2*n + 1, wp)
 
-            y_cc(0) = y_domain%beg + 5d-1*dy
+            y_cc(0) = y_domain%beg + 5e-1_wp*dy
             y_cb(-1) = y_domain%beg
 
             do i = 1, n
-                y_cc(i) = y_domain%beg + 2d0*dy*real(i, kind(0d0))
-                y_cb(i - 1) = y_domain%beg + dy*real(2*i - 1, kind(0d0))
+                y_cc(i) = y_domain%beg + 2._wp*dy*real(i, wp)
+                y_cb(i - 1) = y_domain%beg + dy*real(2*i - 1, wp)
             end do
 
         else
 
-            dy = (y_domain%end - y_domain%beg)/real(n + 1, kind(0d0))
+            dy = (y_domain%end - y_domain%beg)/real(n + 1, wp)
 
             do i = 0, n
-                y_cc(i) = y_domain%beg + 5d-1*dy*real(2*i + 1, kind(0d0))
-                y_cb(i - 1) = y_domain%beg + dy*real(i, kind(0d0))
+                y_cc(i) = y_domain%beg + 5e-1_wp*dy*real(2*i + 1, wp)
+                y_cb(i - 1) = y_domain%beg + dy*real(i, wp)
             end do
 
         end if
@@ -137,12 +137,12 @@ subroutine s_generate_serial_grid
                     y_cb(i) = y_cb(i)/a_y* &
                               (a_y + log(cosh(a_y*(y_cb(i) - y_a))) &
                                + log(cosh(a_y*(y_cb(i) - y_b))) &
-                               - 2d0*log(cosh(a_y*(y_b - y_a)/2d0)))
+                               - 2._wp*log(cosh(a_y*(y_b - y_a)/2._wp)))
                 end do
             end do
 
             y_cb = y_cb*length
-            y_cc = (y_cb(0:n) + y_cb(-1:n - 1))/2d0
+            y_cc = (y_cb(0:n) + y_cb(-1:n - 1))/2._wp
 
             dy = minval(y_cb(0:n) - y_cb(-1:n - 1))
 
@@ -154,11 +154,11 @@ subroutine s_generate_serial_grid
         ! Grid Generation in the z-direction ===============================
         if (p == 0) return
 
-        dz = (z_domain%end - z_domain%beg)/real(p + 1, kind(0d0))
+        dz = (z_domain%end - z_domain%beg)/real(p + 1, wp)
 
         do i = 0, p
-            z_cc(i) = z_domain%beg + 5d-1*dz*real(2*i + 1, kind(0d0))
-            z_cb(i - 1) = z_domain%beg + dz*real(i, kind(0d0))
+            z_cc(i) = z_domain%beg + 5e-1_wp*dz*real(2*i + 1, wp)
+            z_cb(i - 1) = z_domain%beg + dz*real(i, wp)
         end do
 
         z_cb(p) = z_domain%end
@@ -175,12 +175,12 @@ subroutine s_generate_serial_grid
                     z_cb(i) = z_cb(i)/a_z* &
                               (a_z + log(cosh(a_z*(z_cb(i) - z_a))) &
                                + log(cosh(a_z*(z_cb(i) - z_b))) &
-                               - 2d0*log(cosh(a_z*(z_b - z_a)/2d0)))
+                               - 2._wp*log(cosh(a_z*(z_b - z_a)/2._wp)))
                 end do
             end do
 
             z_cb = z_cb*length
-            z_cc = (z_cb(0:p) + z_cb(-1:p - 1))/2d0
+            z_cc = (z_cb(0:p) + z_cb(-1:p - 1))/2._wp
 
             dz = minval(z_cb(0:p) - z_cb(-1:p - 1))
 
@@ -200,10 +200,10 @@ subroutine s_generate_parallel_grid
 
 #ifdef MFC_MPI
 
-        real(kind(0d0)) :: length   !< domain lengths
+        real(wp) :: length   !< domain lengths
 
         ! Locations of cell boundaries
-        real(kind(0d0)), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb !<
+        real(wp), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb !<
             !! Locations of cell boundaries
 
         character(LEN=path_len + name_len) :: file_loc !<
@@ -219,9 +219,9 @@ subroutine s_generate_parallel_grid
         allocate (z_cb_glb(-1:p_glb))
 
         ! Grid generation in the x-direction
-        dx = (x_domain%end - x_domain%beg)/real(m_glb + 1, kind(0d0))
+        dx = (x_domain%end - x_domain%beg)/real(m_glb + 1, wp)
         do i = 0, m_glb
-            x_cb_glb(i - 1) = x_domain%beg + dx*real(i, kind(0d0))
+            x_cb_glb(i - 1) = x_domain%beg + dx*real(i, wp)
         end do
         x_cb_glb(m_glb) = x_domain%end
         if (stretch_x) then
@@ -237,7 +237,7 @@ subroutine s_generate_parallel_grid
                     x_cb_glb(i) = x_cb_glb(i)/a_x* &
                                   (a_x + log(cosh(a_x*(x_cb_glb(i) - x_a))) &
                                    + log(cosh(a_x*(x_cb_glb(i) - x_b))) &
-                                   - 2d0*log(cosh(a_x*(x_b - x_a)/2d0)))
+                                   - 2._wp*log(cosh(a_x*(x_b - x_a)/2._wp)))
                 end do
             end do
 
@@ -248,16 +248,16 @@ subroutine s_generate_parallel_grid
         ! Grid generation in the y-direction
         if (n_glb > 0) then
 
-            if (grid_geometry == 2 .and. y_domain%beg == 0.0d0) then
-                dy = (y_domain%end - y_domain%beg)/real(2*n_glb + 1, kind(0d0))
+            if (grid_geometry == 2 .and. y_domain%beg == 0.0_wp) then
+                dy = (y_domain%end - y_domain%beg)/real(2*n_glb + 1, wp)
                 y_cb_glb(-1) = y_domain%beg
                 do i = 1, n_glb
-                    y_cb_glb(i - 1) = y_domain%beg + dy*real(2*i - 1, kind(0d0))
+                    y_cb_glb(i - 1) = y_domain%beg + dy*real(2*i - 1, wp)
                 end do
             else
-                dy = (y_domain%end - y_domain%beg)/real(n_glb + 1, kind(0d0))
+                dy = (y_domain%end - y_domain%beg)/real(n_glb + 1, wp)
                 do i = 0, n_glb
-                    y_cb_glb(i - 1) = y_domain%beg + dy*real(i, kind(0d0))
+                    y_cb_glb(i - 1) = y_domain%beg + dy*real(i, wp)
                 end do
             end if
             y_cb_glb(n_glb) = y_domain%end
@@ -274,7 +274,7 @@ subroutine s_generate_parallel_grid
                         y_cb_glb(i) = y_cb_glb(i)/a_y* &
                                       (a_y + log(cosh(a_y*(y_cb_glb(i) - y_a))) &
                                        + log(cosh(a_y*(y_cb_glb(i) - y_b))) &
-                                       - 2d0*log(cosh(a_y*(y_b - y_a)/2d0)))
+                                       - 2._wp*log(cosh(a_y*(y_b - y_a)/2._wp)))
                     end do
                 end do
 
@@ -284,9 +284,9 @@ subroutine s_generate_parallel_grid
 
             ! Grid generation in the z-direction
             if (p_glb > 0) then
-                dz = (z_domain%end - z_domain%beg)/real(p_glb + 1, kind(0d0))
+                dz = (z_domain%end - z_domain%beg)/real(p_glb + 1, wp)
                 do i = 0, p_glb
-                    z_cb_glb(i - 1) = z_domain%beg + dz*real(i, kind(0d0))
+                    z_cb_glb(i - 1) = z_domain%beg + dz*real(i, wp)
                 end do
                 z_cb_glb(p_glb) = z_domain%end
                 if (stretch_z) then
@@ -301,7 +301,7 @@ subroutine s_generate_parallel_grid
                             z_cb_glb(i) = z_cb_glb(i)/a_z* &
                                           (a_z + log(cosh(a_z*(z_cb_glb(i) - z_a))) &
                                            + log(cosh(a_z*(z_cb_glb(i) - z_b))) &
-                                           - 2d0*log(cosh(a_z*(z_b - z_a)/2d0)))
+                                           - 2._wp*log(cosh(a_z*(z_b - z_a)/2._wp)))
                         end do
                     end do
 
@@ -316,7 +316,7 @@ subroutine s_generate_parallel_grid
         data_size = m_glb + 2
         call MPI_FILE_OPEN(MPI_COMM_SELF, file_loc, ior(MPI_MODE_WRONLY, MPI_MODE_CREATE), &
                            mpi_info_int, ifile, ierr)
-        call MPI_FILE_WRITE(ifile, x_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+        call MPI_FILE_WRITE(ifile, x_cb_glb, data_size, mpi_p, status, ierr)
         call MPI_FILE_CLOSE(ifile, ierr)
 
         if (n > 0) then
@@ -324,7 +324,7 @@ subroutine s_generate_parallel_grid
             data_size = n_glb + 2
             call MPI_FILE_OPEN(MPI_COMM_SELF, file_loc, ior(MPI_MODE_WRONLY, MPI_MODE_CREATE), &
                                mpi_info_int, ifile, ierr)
-            call MPI_FILE_WRITE(ifile, y_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+            call MPI_FILE_WRITE(ifile, y_cb_glb, data_size, mpi_p, status, ierr)
             call MPI_FILE_CLOSE(ifile, ierr)
 
             if (p > 0) then
@@ -332,7 +332,7 @@ subroutine s_generate_parallel_grid
                 data_size = p_glb + 2
                 call MPI_FILE_OPEN(MPI_COMM_SELF, file_loc, ior(MPI_MODE_WRONLY, MPI_MODE_CREATE), &
                                    mpi_info_int, ifile, ierr)
-                call MPI_FILE_WRITE(ifile, z_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                call MPI_FILE_WRITE(ifile, z_cb_glb, data_size, mpi_p, status, ierr)
                 call MPI_FILE_CLOSE(ifile, ierr)
             end if
         end if
diff --git a/src/pre_process/m_model.fpp b/src/pre_process/m_model.fpp
index 02d316fd5..1e8df1621 100644
--- a/src/pre_process/m_model.fpp
+++ b/src/pre_process/m_model.fpp
@@ -492,19 +492,19 @@ contains
         t_vec3, intent(in) :: spacing
         integer, intent(in) :: spc
 
-        real(kind(0d0)) :: fraction
+        real(wp) :: fraction
 
         type(t_ray) :: ray
         integer :: i, j, nInOrOut, nHits
 
-        real(kind(0d0)), dimension(1:spc, 1:3) :: ray_origins, ray_dirs
+        real(wp), dimension(1:spc, 1:3) :: ray_origins, ray_dirs
 
         do i = 1, spc
             call random_number(ray_origins(i, :))
-            ray_origins(i, :) = point + (ray_origins(i, :) - 0.5)*spacing(:)
+            ray_origins(i, :) = point + (ray_origins(i, :) - 0.5_wp)*spacing(:)
 
             call random_number(ray_dirs(i, :))
-            ray_dirs(i, :) = ray_dirs(i, :) - 0.5
+            ray_dirs(i, :) = ray_dirs(i, :) - 0.5_wp
             ray_dirs(i, :) = ray_dirs(i, :)/sqrt(sum(ray_dirs(i, :)*ray_dirs(i, :)))
         end do
 
@@ -527,7 +527,7 @@ contains
 
     end function f_model_is_inside
 
-    ! From https://www.scratchapixel.com/lessons/3d-basic-rendering/ray-tracing-rendering-a-triangle/ray-triangle-intersection-geometric-solution.html
+    ! From https://www.scratchapixel.com/lessons/3e-basic-rendering/ray-tracing-rendering-a-triangle/ray-triangle-intersection-geometric-solution.html
     !> This procedure checks if a ray intersects a triangle.
     !! @param ray      Ray.
     !! @param triangle Triangle.
@@ -539,8 +539,8 @@ contains
 
         logical :: intersects
 
-        real(kind(0d0)) :: v0v1(3), v0v2(3), N(3), P(3), C(3), edge(3), vp(3)
-        real(kind(0d0)) :: area2, d, t, NdotRayDirection
+        real(wp) :: v0v1(3), v0v2(3), N(3), P(3), C(3), edge(3), vp(3)
+        real(wp) :: area2, d, t, NdotRayDirection
 
         intersects = .false.
 
@@ -549,7 +549,7 @@ contains
 
         NdotRayDirection = sum(N(:)*ray%d(:))
 
-        if (abs(NdotRayDirection) < 0.0000001) then
+        if (abs(NdotRayDirection) < 0.0000001_wp) then
             return
         end if
 
@@ -594,16 +594,16 @@ contains
     !! @param boundary_edge_count        Output total boundary edge counts
     subroutine f_check_boundary(model, boundary_v, boundary_vertex_count, boundary_edge_count)
         type(t_model), intent(in) :: model
-        real(kind(0d0)), allocatable, intent(out), dimension(:, :, :) :: boundary_v !< Output boundary vertices/normals
+        real(wp), allocatable, intent(out), dimension(:, :, :) :: boundary_v !< Output boundary vertices/normals
         integer, intent(out) :: boundary_vertex_count, boundary_edge_count !< Output boundary vertex/edge count
 
         integer :: i, j !< Model index iterator
         integer :: edge_count, edge_index, store_index !< Boundary edge index iterator
-        real(kind(0d0)), dimension(1:2, 1:2) :: edge !< Edge end points buffer
-        real(kind(0d0)), dimension(1:2) :: boundary_edge !< Boundary edge end points buffer
-        real(kind(0d0)), dimension(1:(3*model%ntrs), 1:2, 1:2) :: temp_boundary_v !< Temporary boundary vertex buffer
+        real(wp), dimension(1:2, 1:2) :: edge !< Edge end points buffer
+        real(wp), dimension(1:2) :: boundary_edge !< Boundary edge end points buffer
+        real(wp), dimension(1:(3*model%ntrs), 1:2, 1:2) :: temp_boundary_v !< Temporary boundary vertex buffer
         integer, dimension(1:(3*model%ntrs)) :: edge_occurrence !< The manifoldness of the edges
-        real(kind(0d0)) :: edgetan, initial, v_norm, xnormal, ynormal !< The manifoldness of the edges
+        real(wp) :: edgetan, initial, v_norm, xnormal, ynormal !< The manifoldness of the edges
 
         ! Total number of edges in 2D STL
         edge_count = 3*model%ntrs
@@ -680,12 +680,12 @@ contains
             edgetan = boundary_edge(1)/boundary_edge(2)
 
             if (abs(boundary_edge(2)) < threshold_vector_zero) then
-                if (edgetan > 0d0) then
+                if (edgetan > 0._wp) then
                     ynormal = -1
-                    xnormal = 0d0
+                    xnormal = 0._wp
                 else
                     ynormal = 1
-                    xnormal = 0d0
+                    xnormal = 0._wp
                 end if
             else
                 initial = boundary_edge(2)
@@ -693,7 +693,7 @@ contains
                 xnormal = initial
             end if
 
-            v_norm = dsqrt(xnormal**2 + ynormal**2)
+            v_norm = sqrt(xnormal**2 + ynormal**2)
             boundary_v(i, 3, 1) = xnormal/v_norm
             boundary_v(i, 3, 2) = ynormal/v_norm
         end do
@@ -708,8 +708,8 @@ contains
     subroutine f_register_edge(temp_boundary_v, edge, edge_index, edge_count)
         integer, intent(inout) :: edge_index !< Edge index iterator
         integer, intent(inout) :: edge_count !< Total number of edges
-        real(kind(0d0)), intent(in), dimension(1:2, 1:2) :: edge !< Edges end points to be registered
-        real(kind(0d0)), dimension(1:edge_count, 1:2, 1:2) :: temp_boundary_v !< Temporary edge end vertex buffer
+        real(wp), intent(in), dimension(1:2, 1:2) :: edge !< Edges end points to be registered
+        real(wp), dimension(1:edge_count, 1:2, 1:2) :: temp_boundary_v !< Temporary edge end vertex buffer
 
         ! Increment edge index and store the edge
         edge_index = edge_index + 1
@@ -726,10 +726,10 @@ contains
     subroutine f_check_interpolation_2D(boundary_v, boundary_edge_count, spacing, interpolate)
         logical, intent(inout) :: interpolate !< Logical indicator of interpolation
         integer, intent(in) :: boundary_edge_count !< Number of boundary edges
-        real(kind(0d0)), intent(in), dimension(1:boundary_edge_count, 1:3, 1:2) :: boundary_v
+        real(wp), intent(in), dimension(1:boundary_edge_count, 1:3, 1:2) :: boundary_v
         t_vec3, intent(in) :: spacing
 
-        real(kind(0d0)) :: l1, cell_width !< Length of each boundary edge and cell width
+        real(wp) :: l1, cell_width !< Length of each boundary edge and cell width
         integer :: j !< Boundary edge index iterator
 
         cell_width = minval(spacing(1:2))
@@ -737,8 +737,8 @@ contains
 
         do j = 1, boundary_edge_count
 
-            l1 = dsqrt((boundary_v(j, 2, 1) - boundary_v(j, 1, 1))**2 + &
-                       (boundary_v(j, 2, 2) - boundary_v(j, 1, 2))**2)
+            l1 = sqrt((boundary_v(j, 2, 1) - boundary_v(j, 1, 1))**2 + &
+                      (boundary_v(j, 2, 2) - boundary_v(j, 1, 2))**2)
 
             if ((l1 > cell_width)) then
                 interpolate = .true.
@@ -758,8 +758,8 @@ contains
         type(t_model), intent(in) :: model
         t_vec3, intent(in) :: spacing
         t_vec3 :: edge_l
-        real(kind(0d0)) :: cell_width
-        real(kind(0d0)), dimension(1:3, 1:3) :: tri_v
+        real(wp) :: cell_width
+        real(wp), dimension(1:3, 1:3) :: tri_v
         integer :: i, j !< Loop iterator
 
         cell_width = minval(spacing)
@@ -772,15 +772,15 @@ contains
                 tri_v(3, j) = model%trs(i)%v(3, j)
             end do
 
-            edge_l(1) = dsqrt((tri_v(1, 2) - tri_v(1, 1))**2 + &
-                              (tri_v(2, 2) - tri_v(2, 1))**2 + &
-                              (tri_v(3, 2) - tri_v(3, 1))**2)
-            edge_l(2) = dsqrt((tri_v(1, 3) - tri_v(1, 2))**2 + &
-                              (tri_v(2, 3) - tri_v(2, 2))**2 + &
-                              (tri_v(3, 3) - tri_v(3, 2))**2)
-            edge_l(3) = dsqrt((tri_v(1, 1) - tri_v(1, 3))**2 + &
-                              (tri_v(2, 1) - tri_v(2, 3))**2 + &
-                              (tri_v(3, 1) - tri_v(3, 3))**2)
+            edge_l(1) = sqrt((tri_v(1, 2) - tri_v(1, 1))**2 + &
+                             (tri_v(2, 2) - tri_v(2, 1))**2 + &
+                             (tri_v(3, 2) - tri_v(3, 1))**2)
+            edge_l(2) = sqrt((tri_v(1, 3) - tri_v(1, 2))**2 + &
+                             (tri_v(2, 3) - tri_v(2, 2))**2 + &
+                             (tri_v(3, 3) - tri_v(3, 2))**2)
+            edge_l(3) = sqrt((tri_v(1, 1) - tri_v(1, 3))**2 + &
+                             (tri_v(2, 1) - tri_v(2, 3))**2 + &
+                             (tri_v(3, 1) - tri_v(3, 3))**2)
 
             if ((edge_l(1) > cell_width) .or. &
                 (edge_l(2) > cell_width) .or. &
@@ -800,14 +800,14 @@ contains
     !! @param interpolated_boundary_v      Output all the boundary vertices of the interpolated 2D model
     !! @param total_vertices               Total number of vertices after interpolation
     subroutine f_interpolate_2D(boundary_v, boundary_edge_count, spacing, interpolated_boundary_v, total_vertices)
-        real(kind(0d0)), intent(in), dimension(:, :, :) :: boundary_v
+        real(wp), intent(in), dimension(:, :, :) :: boundary_v
         t_vec3, intent(in) :: spacing
-        real(kind(0d0)), allocatable, intent(inout), dimension(:, :) :: interpolated_boundary_v
+        real(wp), allocatable, intent(inout), dimension(:, :) :: interpolated_boundary_v
 
         integer :: i, j, num_segments, total_vertices, boundary_edge_count
-        real(kind(0d0)) :: edge_length, cell_width
-        real(kind(0d0)), dimension(1:2) :: edge_x, edge_y, edge_del
-        real(kind(0d0)), allocatable :: temp_boundary_v(:, :)
+        real(wp) :: edge_length, cell_width
+        real(wp), dimension(1:2) :: edge_x, edge_y, edge_del
+        real(wp), allocatable :: temp_boundary_v(:, :)
 
         ! Get the number of boundary edges
         cell_width = minval(spacing(1:2))
@@ -823,8 +823,8 @@ contains
             edge_y(2) = boundary_v(i, 2, 2)
 
             ! Compute the length of the edge
-            edge_length = dsqrt((edge_x(2) - edge_x(1))**2 + &
-                                (edge_y(2) - edge_y(1))**2)
+            edge_length = sqrt((edge_x(2) - edge_x(1))**2 + &
+                               (edge_y(2) - edge_y(1))**2)
 
             ! Determine the number of segments
             if (edge_length > cell_width) then
@@ -850,8 +850,8 @@ contains
             edge_y(2) = boundary_v(i, 2, 2)
 
             ! Compute the length of the edge
-            edge_length = dsqrt((edge_x(2) - edge_x(1))**2 + &
-                                (edge_y(2) - edge_y(1))**2)
+            edge_length = sqrt((edge_x(2) - edge_x(1))**2 + &
+                               (edge_y(2) - edge_y(1))**2)
 
             ! Determine the number of segments and interpolation step
             if (edge_length > cell_width) then
@@ -860,13 +860,13 @@ contains
                 edge_del(2) = (edge_y(2) - edge_y(1))/num_segments
             else
                 num_segments = 1
-                edge_del(1) = 0d0
-                edge_del(2) = 0d0
+                edge_del(1) = 0._wp
+                edge_del(2) = 0._wp
             end if
 
             interpolated_boundary_v(1, 1) = edge_x(1)
             interpolated_boundary_v(1, 2) = edge_y(1)
-            interpolated_boundary_v(1, 3) = 0d0
+            interpolated_boundary_v(1, 3) = 0._wp
 
             ! Add original and interpolated vertices to the output array
             do j = 1, num_segments - 1
@@ -893,15 +893,15 @@ contains
     subroutine f_interpolate_3D(model, spacing, interpolated_boundary_v, total_vertices)
         t_vec3, intent(in) :: spacing
         type(t_model), intent(in) :: model
-        real(kind(0d0)), allocatable, intent(inout), dimension(:, :) :: interpolated_boundary_v
+        real(wp), allocatable, intent(inout), dimension(:, :) :: interpolated_boundary_v
         integer, intent(out) :: total_vertices
 
         integer :: i, j, k, num_triangles, num_segments, num_inner_vertices
-        real(kind(0d0)), dimension(1:3, 1:3) :: tri
+        real(wp), dimension(1:3, 1:3) :: tri
         t_vec3 :: edge_del, cell_area
         t_vec3 :: bary_coord !< Barycentric coordinates
-        real(kind(0d0)) :: edge_length, cell_width, cell_area_min, tri_area
-        real(kind(0d0)), allocatable :: temp_boundary_v(:, :)
+        real(wp) :: edge_length, cell_width, cell_area_min, tri_area
+        real(wp), allocatable :: temp_boundary_v(:, :)
 
         ! Number of triangles in the model
         num_triangles = model%ntrs
@@ -928,9 +928,9 @@ contains
                 tri(2, 3) = model%trs(i)%v(mod(j, 3) + 1, 3)
 
                 ! Compute the length of the edge
-                edge_length = dsqrt((tri(2, 1) - tri(1, 1))**2 + &
-                                    (tri(2, 2) - tri(1, 2))**2 + &
-                                    (tri(2, 3) - tri(1, 3))**2)
+                edge_length = sqrt((tri(2, 1) - tri(1, 1))**2 + &
+                                   (tri(2, 2) - tri(1, 2))**2 + &
+                                   (tri(2, 3) - tri(1, 3))**2)
 
                 ! Determine the number of segments
                 if (edge_length > cell_width) then
@@ -975,9 +975,9 @@ contains
                 tri(2, 3) = model%trs(i)%v(mod(j, 3) + 1, 3)
 
                 ! Compute the length of the edge
-                edge_length = dsqrt((tri(2, 1) - tri(1, 1))**2 + &
-                                    (tri(2, 2) - tri(1, 2))**2 + &
-                                    (tri(2, 3) - tri(1, 3))**2)
+                edge_length = sqrt((tri(2, 1) - tri(1, 1))**2 + &
+                                   (tri(2, 2) - tri(1, 2))**2 + &
+                                   (tri(2, 3) - tri(1, 3))**2)
 
                 ! Determine the number of segments and interpolation step
                 if (edge_length > cell_width) then
@@ -987,7 +987,7 @@ contains
                     edge_del(3) = (tri(2, 3) - tri(1, 3))/num_segments
                 else
                     num_segments = 1
-                    edge_del = 0d0
+                    edge_del = 0._wp
                 end if
 
                 ! Add original and interpolated vertices to the output array
@@ -1020,11 +1020,11 @@ contains
                     call random_number(bary_coord(1))
                     call random_number(bary_coord(2))
 
-                    if ((bary_coord(1) + bary_coord(2)) >= 1.0d0) then
-                        bary_coord(1) = 1d0 - bary_coord(1)
-                        bary_coord(2) = 1d0 - bary_coord(2)
+                    if ((bary_coord(1) + bary_coord(2)) >= 1._wp) then
+                        bary_coord(1) = 1._wp - bary_coord(1)
+                        bary_coord(2) = 1._wp - bary_coord(2)
                     end if
-                    bary_coord(3) = 1d0 - bary_coord(1) - bary_coord(2)
+                    bary_coord(3) = 1._wp - bary_coord(1) - bary_coord(2)
 
                     total_vertices = total_vertices + 1
                     interpolated_boundary_v(total_vertices, 1) = dot_product(bary_coord, tri(1:3, 1))
@@ -1045,19 +1045,19 @@ contains
         type(t_model), intent(IN) :: model
         t_vec3, intent(in) :: point
         t_vec3, intent(out) :: normals
-        real(kind(0d0)), intent(out) :: distance
+        real(wp), intent(out) :: distance
 
-        real(kind(0d0)), dimension(1:model%ntrs, 1:3) :: tri_normals
-        real(kind(0d0)), dimension(1:3, 1:3) :: tri
-        real(kind(0d0)) :: dist_min, dist_t_min
-        real(kind(0d0)) :: dist_min_normal, dist_buffer_normal
+        real(wp), dimension(1:model%ntrs, 1:3) :: tri_normals
+        real(wp), dimension(1:3, 1:3) :: tri
+        real(wp) :: dist_min, dist_t_min
+        real(wp) :: dist_min_normal, dist_buffer_normal
         t_vec3 :: midp !< Centers of the triangle facets
         t_vec3 :: dist_buffer !< Distance between the cell center and the vertices
         integer :: i, j, tri_idx !< Iterator
 
-        dist_min = 1d12
-        dist_min_normal = 1d12
-        distance = 0d0
+        dist_min = 1e12_wp
+        dist_min_normal = 1e12_wp
+        distance = 0._wp
 
         tri_idx = 0
         do i = 1, model%ntrs
@@ -1065,9 +1065,9 @@ contains
                 tri(j, 1) = model%trs(i)%v(j, 1)
                 tri(j, 2) = model%trs(i)%v(j, 2)
                 tri(j, 3) = model%trs(i)%v(j, 3)
-                dist_buffer(j) = dsqrt((point(1) - tri(j, 1))**2 + &
-                                       (point(2) - tri(j, 2))**2 + &
-                                       (point(3) - tri(j, 3))**2)
+                dist_buffer(j) = sqrt((point(1) - tri(j, 1))**2 + &
+                                      (point(2) - tri(j, 2))**2 + &
+                                      (point(3) - tri(j, 3))**2)
             end do
 
             ! Get the surface center of each triangle facet
@@ -1076,9 +1076,9 @@ contains
             end do
 
             dist_t_min = minval(dist_buffer(1:3))
-            dist_buffer_normal = dsqrt((point(1) - midp(1))**2 + &
-                                       (point(2) - midp(2))**2 + &
-                                       (point(3) - midp(3))**2)
+            dist_buffer_normal = sqrt((point(1) - midp(1))**2 + &
+                                      (point(2) - midp(2))**2 + &
+                                      (point(3) - midp(3))**2)
 
             if (dist_t_min < dist_min) then
                 dist_min = dist_t_min
@@ -1106,21 +1106,21 @@ contains
     !! @return                             Distance which the levelset distance without interpolation
     function f_distance(boundary_v, boundary_vertex_count, boundary_edge_count, point, spacing) result(distance)
         integer, intent(in) :: boundary_vertex_count, boundary_edge_count
-        real(kind(0d0)), intent(in), dimension(1:boundary_edge_count, 1:3, 1:2) :: boundary_v
+        real(wp), intent(in), dimension(1:boundary_edge_count, 1:3, 1:2) :: boundary_v
         t_vec3, intent(in) :: point
         t_vec3, intent(in) :: spacing
 
         integer :: i
-        real(kind(0d0)) :: dist_buffer1, dist_buffer2
-        real(kind(0d0)), dimension(1:boundary_edge_count) :: dist_buffer
-        real(kind(0d0)) :: distance
+        real(wp) :: dist_buffer1, dist_buffer2
+        real(wp), dimension(1:boundary_edge_count) :: dist_buffer
+        real(wp) :: distance
 
-        distance = 0d0
+        distance = 0._wp
         do i = 1, boundary_edge_count
-            dist_buffer1 = dsqrt((point(1) - boundary_v(i, 1, 1))**2 + &
+            dist_buffer1 = sqrt((point(1) - boundary_v(i, 1, 1))**2 + &
                                 & (point(2) - boundary_v(i, 1, 2))**2)
 
-            dist_buffer2 = dsqrt((point(1) - boundary_v(i, 2, 1))**2 + &
+            dist_buffer2 = sqrt((point(1) - boundary_v(i, 2, 1))**2 + &
                                 & (point(2) - boundary_v(i, 2, 2))**2)
 
             dist_buffer(i) = minval((/dist_buffer1, dist_buffer2/))
@@ -1139,25 +1139,25 @@ contains
     !! @param normals                      Output levelset normals without interpolation
     subroutine f_normals(boundary_v, boundary_vertex_count, boundary_edge_count, point, spacing, normals)
         integer, intent(in) :: boundary_vertex_count, boundary_edge_count
-        real(kind(0d0)), intent(in), dimension(1:boundary_edge_count, 1:3, 1:2) :: boundary_v
+        real(wp), intent(in), dimension(1:boundary_edge_count, 1:3, 1:2) :: boundary_v
         t_vec3, intent(in) :: point
         t_vec3, intent(in) :: spacing
         t_vec3, intent(out) :: normals
 
         integer :: i, idx_buffer
-        real(kind(0d0)) :: dist_min, dist_buffer
-        real(kind(0d0)) :: midp(1:3)
+        real(wp) :: dist_min, dist_buffer
+        real(wp) :: midp(1:3)
 
-        dist_buffer = 0d0
+        dist_buffer = 0._wp
         dist_min = initial_distance_buffer
         idx_buffer = 0
 
         do i = 1, boundary_edge_count
             midp(1) = (boundary_v(i, 2, 1) + boundary_v(i, 1, 1))/2
             midp(2) = (boundary_v(i, 2, 2) + boundary_v(i, 1, 2))/2
-            midp(3) = 0d0
+            midp(3) = 0._wp
 
-            dist_buffer = dsqrt((point(1) - midp(1))**2 + &
+            dist_buffer = sqrt((point(1) - midp(1))**2 + &
                                 & (point(2) - midp(2))**2)
 
             if (dist_buffer < dist_min) then
@@ -1168,7 +1168,7 @@ contains
 
         normals(1) = boundary_v(idx_buffer, 3, 1)
         normals(2) = boundary_v(idx_buffer, 3, 2)
-        normals(3) = 0d0
+        normals(3) = 0._wp
 
     end subroutine f_normals
 
@@ -1180,22 +1180,22 @@ contains
     !! @return                             Distance which the levelset distance without interpolation
     function f_interpolated_distance(interpolated_boundary_v, total_vertices, point, spacing) result(distance)
         integer, intent(in) :: total_vertices
-        real(kind(0d0)), intent(in), dimension(1:total_vertices, 1:3) :: interpolated_boundary_v
+        real(wp), intent(in), dimension(1:total_vertices, 1:3) :: interpolated_boundary_v
         t_vec3, intent(in) :: point
         t_vec3, intent(in) :: spacing
 
         integer :: i !< Loop iterator
-        real(kind(0d0)) :: dist_buffer, min_dist
-        real(kind(0d0)) :: distance
+        real(wp) :: dist_buffer, min_dist
+        real(wp) :: distance
 
         distance = initial_distance_buffer
         dist_buffer = initial_distance_buffer
         min_dist = initial_distance_buffer
 
         do i = 1, total_vertices
-            dist_buffer = dsqrt((point(1) - interpolated_boundary_v(i, 1))**2 + &
-                                (point(2) - interpolated_boundary_v(i, 2))**2 + &
-                                (point(3) - interpolated_boundary_v(i, 3))**2)
+            dist_buffer = sqrt((point(1) - interpolated_boundary_v(i, 1))**2 + &
+                               (point(2) - interpolated_boundary_v(i, 2))**2 + &
+                               (point(3) - interpolated_boundary_v(i, 3))**2)
 
             if (min_dist > dist_buffer) then
                 min_dist = dist_buffer
@@ -1208,9 +1208,9 @@ contains
 
     !> This procedure calculates the barycentric facet area
     function f_tri_area(tri) result(tri_area)
-        real(kind(0d0)), dimension(1:3, 1:3), intent(in) :: tri
+        real(wp), dimension(1:3, 1:3), intent(in) :: tri
         t_vec3 :: AB, AC, cross
-        real(kind(0d0)) :: tri_area
+        real(wp) :: tri_area
         integer :: i !< Loop iterator
 
         do i = 1, 3
@@ -1221,7 +1221,7 @@ contains
         cross(1) = AB(2)*AC(3) - AB(3)*AC(2)
         cross(2) = AB(3)*AC(1) - AB(1)*AC(3)
         cross(3) = AB(1)*AC(2) - AB(2)*AC(1)
-        tri_area = 0.5d0*dsqrt(cross(1)**2 + cross(2)**2 + cross(3)**2)
+        tri_area = 0.5_wp*sqrt(cross(1)**2 + cross(2)**2 + cross(3)**2)
 
     end function f_tri_area
 
diff --git a/src/pre_process/m_mpi_proxy.fpp b/src/pre_process/m_mpi_proxy.fpp
index c68767c41..4673d3424 100644
--- a/src/pre_process/m_mpi_proxy.fpp
+++ b/src/pre_process/m_mpi_proxy.fpp
@@ -69,7 +69,7 @@ contains
             & 'Web', 'Ca', 'Re_inv', 'sigR', 'sigV', 'rhoRV', 'palpha_eps',    &
             & 'ptgalpha_eps', 'sigma', 'pi_fac', 'mixlayer_vel_coef',          &
             & 'mixlayer_domain' ]
-            call MPI_BCAST(${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
         #:endfor
 
         do i = 1, num_patches_max
@@ -85,14 +85,14 @@ contains
                 & 'beta', 'smooth_coeff', 'rho', 'p0', 'm0', 'r0', 'v0',       &
                 & 'pres', 'gamma', 'pi_inf', 'hcid', 'cv', 'qv', 'qvp',        &
                 & 'model_threshold', 'cf_val']
-                call MPI_BCAST(patch_icpp(i)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(patch_icpp(i)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
 
             call MPI_BCAST(patch_icpp(i)%model_filepath, len(patch_icpp(i)%model_filepath), MPI_CHARACTER, 0, MPI_COMM_WORLD, ierr)
 
             #:for VAR in [ 'model_translate', 'model_scale', 'model_rotate', &
                 'normal', 'radii', 'vel', 'tau_e', 'alpha_rho', 'alpha' ]
-                call MPI_BCAST(patch_icpp(i)%${VAR}$, size(patch_icpp(i)%${VAR}$), MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(patch_icpp(i)%${VAR}$, size(patch_icpp(i)%${VAR}$), mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
 
             call MPI_BCAST(patch_icpp(i)%model_spc, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, ierr)
@@ -105,7 +105,7 @@ contains
 
             #:for VAR in [ 'x_centroid', 'y_centroid', 'z_centroid',           &
                 & 'length_x', 'length_y', 'length_z', 'radius', 'c', 'p', 't', 'm', 'theta', 'slip']
-                call MPI_BCAST(patch_ib(i)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(patch_ib(i)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
 
             #:for VAR in [ 'model_translate', 'model_scale', 'model_rotate']
@@ -117,7 +117,7 @@ contains
         do i = 1, num_fluids_max
             #:for VAR in [ 'gamma','pi_inf','mul0','ss','pv','gamma_v','M_v',  &
                 & 'mu_v','k_v', 'G', 'cv', 'qv', 'qvp' ]
-                call MPI_BCAST(fluid_pp(i)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(fluid_pp(i)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
         end do
 #endif
@@ -138,10 +138,10 @@ contains
 
         ! Temporary # of processors in x-, y- and z-coordinate directions
         ! used during the processor factorization optimization procedure
-        real(kind(0d0)) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z
+        real(wp) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z
 
         ! Processor factorization (fct) minimization parameter
-        real(kind(0d0)) :: fct_min
+        real(wp) :: fct_min
 
         ! Cartesian processor topology communicator
         integer :: MPI_COMM_CART
@@ -187,8 +187,8 @@ contains
                     tmp_num_procs_x = num_procs_x
                     tmp_num_procs_y = num_procs_y
                     tmp_num_procs_z = num_procs_z
-                    fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                       - (n + 1)/tmp_num_procs_y)
+                    fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                         - (n + 1)/tmp_num_procs_y)
 
                     ! Searching for optimal computational domain distribution
                     do i = 1, num_procs
@@ -231,10 +231,10 @@ contains
                     tmp_num_procs_x = num_procs_x
                     tmp_num_procs_y = num_procs_y
                     tmp_num_procs_z = num_procs_z
-                    fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                       - (n + 1)/tmp_num_procs_y) &
-                              + 10d0*abs((n + 1)/tmp_num_procs_y &
-                                         - (p + 1)/tmp_num_procs_z)
+                    fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                         - (n + 1)/tmp_num_procs_y) &
+                              + 10._wp*abs((n + 1)/tmp_num_procs_y &
+                                           - (p + 1)/tmp_num_procs_z)
 
                     ! Searching for optimal computational domain distribution
                     do i = 1, num_procs
@@ -313,7 +313,7 @@ contains
 
                 ! Preliminary uniform cell-width spacing
                 if (old_grid .neqv. .true.) then
-                    dz = (z_domain%end - z_domain%beg)/real(p + 1, kind(0d0))
+                    dz = (z_domain%end - z_domain%beg)/real(p + 1, wp)
                 end if
 
                 ! Optimal number of cells per processor
@@ -365,8 +365,8 @@ contains
                 ! Computing minimization variable for these initial values
                 tmp_num_procs_x = num_procs_x
                 tmp_num_procs_y = num_procs_y
-                fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                   - (n + 1)/tmp_num_procs_y)
+                fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                     - (n + 1)/tmp_num_procs_y)
 
                 ! Searching for optimal computational domain distribution
                 do i = 1, num_procs
@@ -428,7 +428,7 @@ contains
 
             ! Preliminary uniform cell-width spacing
             if (old_grid .neqv. .true.) then
-                dy = (y_domain%end - y_domain%beg)/real(n + 1, kind(0d0))
+                dy = (y_domain%end - y_domain%beg)/real(n + 1, wp)
             end if
 
             ! Optimal number of cells per processor
@@ -497,7 +497,7 @@ contains
 
         ! Preliminary uniform cell-width spacing
         if (old_grid .neqv. .true.) then
-            dx = (x_domain%end - x_domain%beg)/real(m + 1, kind(0d0))
+            dx = (x_domain%end - x_domain%beg)/real(m + 1, wp)
         end if
 
         ! Optimal number of cells per processor
diff --git a/src/pre_process/m_patches.fpp b/src/pre_process/m_patches.fpp
index d0a00c3c4..d3151a717 100644
--- a/src/pre_process/m_patches.fpp
+++ b/src/pre_process/m_patches.fpp
@@ -54,24 +54,24 @@ module m_patches
               s_sweep_plane, &
               s_model
 
-    real(kind(0d0)) :: x_centroid, y_centroid, z_centroid
-    real(kind(0d0)) :: length_x, length_y, length_z
+    real(wp) :: x_centroid, y_centroid, z_centroid
+    real(wp) :: length_x, length_y, length_z
 
     integer :: smooth_patch_id
-    real(kind(0d0)) :: smooth_coeff !<
+    real(wp) :: smooth_coeff !<
     !! These variables are analogous in both meaning and use to the similarly
     !! named components in the ic_patch_parameters type (see m_derived_types.f90
     !! for additional details). They are employed as a means to more concisely
     !! perform the actions necessary to lay out a particular patch on the grid.
 
-    real(kind(0d0)) :: eta !<
+    real(wp) :: eta !<
     !! In the case that smoothing of patch boundaries is enabled and the boundary
     !! between two adjacent patches is to be smeared out, this variable's purpose
     !! is to act as a pseudo volume fraction to indicate the contribution of each
     !! patch toward the composition of a cell's fluid state.
 
-    real(kind(0d0)) :: cart_y, cart_z
-    real(kind(0d0)) :: sph_phi !<
+    real(wp) :: cart_y, cart_z
+    real(wp) :: sph_phi !<
     !! Variables to be used to hold cell locations in Cartesian coordinates if
     !! 3D simulation is using cylindrical coordinates
 
@@ -99,13 +99,13 @@ contains
         integer, dimension(0:m, 0:n, 0:p), intent(inout) :: patch_id_fp
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
-        real(kind(0d0)) :: pi_inf, gamma, lit_gamma
+        real(wp) :: pi_inf, gamma, lit_gamma
 
         integer :: i, j, k !< Generic loop operators
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the line segment's centroid and length information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -113,14 +113,14 @@ contains
 
         ! Computing the beginning and end x-coordinates of the line segment
         ! based on its centroid and length
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
 
         ! Since the line segment patch does not allow for its boundaries to
         ! be smoothed out, the pseudo volume fraction is set to 1 to ensure
         ! that only the current patch contributes to the fluid state in the
         ! cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the line segment covers a particular cell in the
         ! domain and verifying whether the current patch has the permission
@@ -137,7 +137,7 @@ contains
                 @:analytical()
 
                 ! Updating the patch identities bookkeeping variable
-                if (1d0 - eta < 1d-16) patch_id_fp(i, 0, 0) = patch_id
+                if (1._wp - eta < 1e-16_wp) patch_id_fp(i, 0, 0) = patch_id
 
             end if
         end do
@@ -158,8 +158,8 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< Generic loop iterators
-        real(kind(0d0)) :: th, thickness, nturns, mya
-        real(kind(0d0)) :: spiral_x_min, spiral_x_max, spiral_y_min, spiral_y_max
+        real(wp) :: th, thickness, nturns, mya
+        real(wp) :: spiral_x_min, spiral_x_max, spiral_y_min, spiral_y_max
 
         ! Transferring the circular patch's radius, centroid, smearing patch
         ! identity and smearing coefficient information
@@ -172,16 +172,16 @@ contains
         !
         logic_grid = 0
         do k = 0, int(m*91*nturns)
-            th = k/real(int(m*91d0*nturns))*nturns*2.d0*pi
+            th = k/real(int(m*91._wp*nturns))*nturns*2._wp*pi
 
-            spiral_x_min = minval((/f_r(th, 0.0d0, mya)*cos(th), &
+            spiral_x_min = minval((/f_r(th, 0.0_wp, mya)*cos(th), &
                                     f_r(th, thickness, mya)*cos(th)/))
-            spiral_y_min = minval((/f_r(th, 0.0d0, mya)*sin(th), &
+            spiral_y_min = minval((/f_r(th, 0.0_wp, mya)*sin(th), &
                                     f_r(th, thickness, mya)*sin(th)/))
 
-            spiral_x_max = maxval((/f_r(th, 0.0d0, mya)*cos(th), &
+            spiral_x_max = maxval((/f_r(th, 0.0_wp, mya)*cos(th), &
                                     f_r(th, thickness, mya)*cos(th)/))
-            spiral_y_max = maxval((/f_r(th, 0.0d0, mya)*sin(th), &
+            spiral_y_max = maxval((/f_r(th, 0.0_wp, mya)*sin(th), &
                                     f_r(th, thickness, mya)*sin(th)/))
 
             do j = 0, n; do i = 0, m; 
@@ -201,7 +201,7 @@ contains
                     @:analytical()
 
                     ! Updating the patch identities bookkeeping variable
-                    if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                    if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
                 end if
             end do
         end do
@@ -224,7 +224,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
         logical, optional, intent(in) :: ib
 
-        real(kind(0d0)) :: radius
+        real(wp) :: radius
 
         integer :: i, j, k !< Generic loop iterators
 
@@ -246,7 +246,7 @@ contains
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smoothing of the circular patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the circle covers a particular cell in the domain
         ! and verifying whether the current patch has permission to write to
@@ -261,7 +261,7 @@ contains
                     eta = tanh(smooth_coeff/min(dx, dy)* &
                                (sqrt((x_cc(i) - x_centroid)**2 &
                                      + (y_cc(j) - y_centroid)**2) &
-                                - radius))*(-0.5d0) + 0.5d0
+                                - radius))*(-0.5_wp) + 0.5_wp
 
                 end if
 
@@ -301,7 +301,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
         logical, optional, intent(in) :: ib
 
-        real(kind(0d0)) :: x0, y0, f, x_act, y_act, ca, pa, ma, ta, theta, xa, ya, yt, xu, yu, xl, yl, xc, yc, dycdxc, sin_c, cos_c
+        real(wp) :: x0, y0, f, x_act, y_act, ca, pa, ma, ta, theta, xa, ya, yt, xu, yu, xl, yl, xc, yc, dycdxc, sin_c, cos_c
         integer :: i, j, k, l
         integer :: Np1, Np2
 
@@ -312,7 +312,7 @@ contains
         pa = patch_ib(patch_id)%p
         ma = patch_ib(patch_id)%m
         ta = patch_ib(patch_id)%t
-        theta = pi*patch_ib(patch_id)%theta/180d0
+        theta = pi*patch_ib(patch_id)%theta/180._wp
 
         Np1 = int((pa*ca/dx)*20)
         Np2 = int(((ca - pa*ca)/dx)*20)
@@ -327,7 +327,7 @@ contains
         airfoil_grid_l(1)%x = x0
         airfoil_grid_l(1)%y = y0
 
-        eta = 1d0
+        eta = 1._wp
 
         do i = 1, Np1 + Np2 - 1
             if (i <= Np1) then
@@ -342,9 +342,9 @@ contains
                 dycdxc = (2*ma/(1 - pa)**2)*(pa - xa)
             end if
 
-            yt = (5d0*ta)*(0.2969*xa**0.5d0 - 0.126*xa - 0.3516*xa**2d0 + 0.2843*xa**3 - 0.1015*xa**4)
-            sin_c = dycdxc/(1 + dycdxc**2)**0.5
-            cos_c = 1/(1 + dycdxc**2)**0.5
+            yt = (5._wp*ta)*(0.2969_wp*xa**0.5_wp - 0.126_wp*xa - 0.3516_wp*xa**2._wp + 0.2843_wp*xa**3 - 0.1015_wp*xa**4)
+            sin_c = dycdxc/(1 + dycdxc**2)**0.5_wp
+            cos_c = 1/(1 + dycdxc**2)**0.5_wp
 
             xu = xa - yt*sin_c
             yu = yc + yt*cos_c
@@ -406,7 +406,7 @@ contains
                             end if
                         else
                             f = (airfoil_grid_u(k)%x - x_act)/(airfoil_grid_u(k)%x - airfoil_grid_u(k - 1)%x)
-                            if (y_act <= ((1d0 - f)*airfoil_grid_u(k)%y + f*airfoil_grid_u(k - 1)%y)) then
+                            if (y_act <= ((1._wp - f)*airfoil_grid_u(k)%y + f*airfoil_grid_u(k - 1)%y)) then
                                 !!IB
                                 !call s_assign_patch_primitive_variables(patch_id, i, j, 0, &
                                 !eta, q_prim_vf, patch_id_fp)
@@ -428,7 +428,7 @@ contains
                         else
                             f = (airfoil_grid_l(k)%x - x_act)/(airfoil_grid_l(k)%x - airfoil_grid_l(k - 1)%x)
 
-                            if (y_act >= ((1d0 - f)*airfoil_grid_l(k)%y + f*airfoil_grid_l(k - 1)%y)) then
+                            if (y_act >= ((1._wp - f)*airfoil_grid_l(k)%y + f*airfoil_grid_l(k - 1)%y)) then
                                    !!IB
                                 !call s_assign_patch_primitive_variables(patch_id, i, j, 0, &
                                 !eta, q_prim_vf, patch_id_fp)
@@ -443,10 +443,10 @@ contains
         if (.not. f_is_default(patch_ib(patch_id)%theta)) then
             do i = 1, Np
                 airfoil_grid_l(i)%x = (airfoil_grid_l(i)%x - x0)*cos(theta) + (airfoil_grid_l(i)%y - y0)*sin(theta) + x0
-                airfoil_grid_l(i)%y = -1d0*(airfoil_grid_l(i)%x - x0)*sin(theta) + (airfoil_grid_l(i)%y - y0)*cos(theta) + y0
+                airfoil_grid_l(i)%y = -1._wp*(airfoil_grid_l(i)%x - x0)*sin(theta) + (airfoil_grid_l(i)%y - y0)*cos(theta) + y0
 
                 airfoil_grid_u(i)%x = (airfoil_grid_u(i)%x - x0)*cos(theta) + (airfoil_grid_u(i)%y - y0)*sin(theta) + x0
-                airfoil_grid_u(i)%y = -1d0*(airfoil_grid_u(i)%x - x0)*sin(theta) + (airfoil_grid_u(i)%y - y0)*cos(theta) + y0
+                airfoil_grid_u(i)%y = -1._wp*(airfoil_grid_u(i)%x - x0)*sin(theta) + (airfoil_grid_u(i)%y - y0)*cos(theta) + y0
             end do
         end if
 
@@ -463,7 +463,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
         logical, optional, intent(in) :: ib
 
-        real(kind(0d0)) :: x0, y0, z0, lz, z_max, z_min, f, x_act, y_act, ca, pa, ma, ta, theta, xa, ya, yt, xu, yu, xl, yl, xc, yc, dycdxc, sin_c, cos_c
+        real(wp) :: x0, y0, z0, lz, z_max, z_min, f, x_act, y_act, ca, pa, ma, ta, theta, xa, ya, yt, xu, yu, xl, yl, xc, yc, dycdxc, sin_c, cos_c
         integer :: i, j, k, l
         integer :: Np1, Np2
 
@@ -476,7 +476,7 @@ contains
         pa = patch_ib(patch_id)%p
         ma = patch_ib(patch_id)%m
         ta = patch_ib(patch_id)%t
-        theta = pi*patch_ib(patch_id)%theta/180d0
+        theta = pi*patch_ib(patch_id)%theta/180._wp
 
         Np1 = int((pa*ca/dx)*20)
         Np2 = int(((ca - pa*ca)/dx)*20)
@@ -494,7 +494,7 @@ contains
         z_max = z0 + lz/2
         z_min = z0 - lz/2
 
-        eta = 1d0
+        eta = 1._wp
 
         do i = 1, Np1 + Np2 - 1
             if (i <= Np1) then
@@ -509,9 +509,9 @@ contains
                 dycdxc = (2*ma/(1 - pa)**2)*(pa - xa)
             end if
 
-            yt = (5d0*ta)*(0.2969*xa**0.5d0 - 0.126*xa - 0.3516*xa**2d0 + 0.2843*xa**3 - 0.1015*xa**4)
-            sin_c = dycdxc/(1 + dycdxc**2)**0.5
-            cos_c = 1/(1 + dycdxc**2)**0.5
+            yt = (5._wp*ta)*(0.2969_wp*xa**0.5_wp - 0.126_wp*xa - 0.3516_wp*xa**2._wp + 0.2843_wp*xa**3 - 0.1015_wp*xa**4)
+            sin_c = dycdxc/(1 + dycdxc**2)**0.5_wp
+            cos_c = 1/(1 + dycdxc**2)**0.5_wp
 
             xu = xa - yt*sin_c
             yu = yc + yt*cos_c
@@ -575,7 +575,7 @@ contains
                                     end if
                                 else
                                     f = (airfoil_grid_u(k)%x - x_act)/(airfoil_grid_u(k)%x - airfoil_grid_u(k - 1)%x)
-                                    if (y_act <= ((1d0 - f)*airfoil_grid_u(k)%y + f*airfoil_grid_u(k - 1)%y)) then
+                                    if (y_act <= ((1._wp - f)*airfoil_grid_u(k)%y + f*airfoil_grid_u(k - 1)%y)) then
                                         !!IB
                                         !call s_assign_patch_primitive_variables(patch_id, i, j, 0, &
                                         !eta, q_prim_vf, patch_id_fp)
@@ -597,7 +597,7 @@ contains
                                 else
                                     f = (airfoil_grid_l(k)%x - x_act)/(airfoil_grid_l(k)%x - airfoil_grid_l(k - 1)%x)
 
-                                    if (y_act >= ((1d0 - f)*airfoil_grid_l(k)%y + f*airfoil_grid_l(k - 1)%y)) then
+                                    if (y_act >= ((1._wp - f)*airfoil_grid_l(k)%y + f*airfoil_grid_l(k - 1)%y)) then
                                            !!IB
                                         !call s_assign_patch_primitive_variables(patch_id, i, j, 0, &
                                         !eta, q_prim_vf, patch_id_fp)
@@ -614,10 +614,10 @@ contains
         if (.not. f_is_default(patch_ib(patch_id)%theta)) then
             do i = 1, Np
                 airfoil_grid_l(i)%x = (airfoil_grid_l(i)%x - x0)*cos(theta) + (airfoil_grid_l(i)%y - y0)*sin(theta) + x0
-                airfoil_grid_l(i)%y = -1d0*(airfoil_grid_l(i)%x - x0)*sin(theta) + (airfoil_grid_l(i)%y - y0)*cos(theta) + y0
+                airfoil_grid_l(i)%y = -1._wp*(airfoil_grid_l(i)%x - x0)*sin(theta) + (airfoil_grid_l(i)%y - y0)*cos(theta) + y0
 
                 airfoil_grid_u(i)%x = (airfoil_grid_u(i)%x - x0)*cos(theta) + (airfoil_grid_u(i)%y - y0)*sin(theta) + x0
-                airfoil_grid_u(i)%y = -1d0*(airfoil_grid_u(i)%x - x0)*sin(theta) + (airfoil_grid_u(i)%y - y0)*cos(theta) + y0
+                airfoil_grid_u(i)%y = -1._wp*(airfoil_grid_u(i)%x - x0)*sin(theta) + (airfoil_grid_u(i)%y - y0)*cos(theta) + y0
             end do
         end if
 
@@ -637,7 +637,7 @@ contains
 
         ! Generic loop iterators
         integer :: i, j, k
-        real(kind(0d0)) :: radius, myr, thickness
+        real(wp) :: radius, myr, thickness
 
         ! Transferring the circular patch's radius, centroid, smearing patch
         ! identity and smearing coefficient information
@@ -651,7 +651,7 @@ contains
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smoothing of the circular patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the circle covers a particular cell in the domain
         ! and verifying whether the current patch has permission to write to
@@ -659,11 +659,11 @@ contains
         ! the current patch are assigned to this cell.
         do j = 0, n
             do i = 0, m
-                myr = dsqrt((x_cc(i) - x_centroid)**2 &
-                            + (y_cc(j) - y_centroid)**2)
+                myr = sqrt((x_cc(i) - x_centroid)**2 &
+                           + (y_cc(j) - y_centroid)**2)
 
-                if (myr <= radius + thickness/2.d0 .and. &
-                    myr >= radius - thickness/2.d0 .and. &
+                if (myr <= radius + thickness/2._wp .and. &
+                    myr >= radius - thickness/2._wp .and. &
                     patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, 0))) then
 
                     call s_assign_patch_primitive_variables(patch_id, i, j, 0, &
@@ -672,10 +672,10 @@ contains
                     @:analytical()
 
                     ! Updating the patch identities bookkeeping variable
-                    if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                    if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
 
                     q_prim_vf(alf_idx)%sf(i, j, 0) = patch_icpp(patch_id)%alpha(1)* &
-                                                     dexp(-0.5d0*((myr - radius)**2.d0)/(thickness/3.d0)**2.d0)
+                                                     exp(-0.5_wp*((myr - radius)**2._wp)/(thickness/3._wp)**2._wp)
                 end if
 
             end do
@@ -695,7 +695,7 @@ contains
 
         ! Generic loop iterators
         integer :: i, j, k
-        real(kind(0d0)) :: radius, myr, thickness
+        real(wp) :: radius, myr, thickness
 
         ! Transferring the circular patch's radius, centroid, smearing patch
         ! identity and smearing coefficient information
@@ -711,7 +711,7 @@ contains
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smoothing of the circular patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! write for all z
 
@@ -722,11 +722,11 @@ contains
         do k = 0, p
             do j = 0, n
                 do i = 0, m
-                    myr = dsqrt((x_cc(i) - x_centroid)**2 &
-                                + (y_cc(j) - y_centroid)**2)
+                    myr = sqrt((x_cc(i) - x_centroid)**2 &
+                               + (y_cc(j) - y_centroid)**2)
 
-                    if (myr <= radius + thickness/2.d0 .and. &
-                        myr >= radius - thickness/2.d0 .and. &
+                    if (myr <= radius + thickness/2._wp .and. &
+                        myr >= radius - thickness/2._wp .and. &
                         patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, k))) then
 
                         call s_assign_patch_primitive_variables(patch_id, i, j, k, &
@@ -735,10 +735,10 @@ contains
                         @:analytical()
 
                         ! Updating the patch identities bookkeeping variable
-                        if (1d0 - eta < 1d-16) patch_id_fp(i, j, k) = patch_id
+                        if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, k) = patch_id
 
                         q_prim_vf(alf_idx)%sf(i, j, k) = patch_icpp(patch_id)%alpha(1)* &
-                                                         dexp(-0.5d0*((myr - radius)**2.d0)/(thickness/3.d0)**2.d0)
+                                                         exp(-0.5_wp*((myr - radius)**2._wp)/(thickness/3._wp)**2._wp)
                     end if
 
                 end do
@@ -761,7 +761,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< Generic loop operators
-        real(kind(0d0)) :: a, b
+        real(wp) :: a, b
 
         ! Transferring the elliptical patch's radii, centroid, smearing
         ! patch identity, and smearing coefficient information
@@ -776,7 +776,7 @@ contains
         ! be modified as the patch is laid out on the grid, but only in
         ! the case that smoothing of the elliptical patch's boundary is
         ! enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the ellipse covers a particular cell in the
         ! domain and verifying whether the current patch has permission
@@ -789,11 +789,11 @@ contains
                     eta = tanh(smooth_coeff/min(dx, dy)* &
                                (sqrt(((x_cc(i) - x_centroid)/a)**2 + &
                                      ((y_cc(j) - y_centroid)/b)**2) &
-                                - 1d0))*(-0.5d0) + 0.5d0
+                                - 1._wp))*(-0.5_wp) + 0.5_wp
                 end if
 
                 if ((((x_cc(i) - x_centroid)/a)**2 + &
-                     ((y_cc(j) - y_centroid)/b)**2 <= 1d0 &
+                     ((y_cc(j) - y_centroid)/b)**2 <= 1._wp &
                      .and. &
                      patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, 0))) &
                     .or. &
@@ -806,7 +806,7 @@ contains
                     @:analytical()
 
                     ! Updating the patch identities bookkeeping variable
-                    if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                    if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
                 end if
             end do
         end do
@@ -829,7 +829,7 @@ contains
 
         ! Generic loop iterators
         integer :: i, j, k
-        real(kind(0d0)) :: a, b, c
+        real(wp) :: a, b, c
 
         ! Transferring the ellipsoidal patch's radii, centroid, smearing
         ! patch identity, and smearing coefficient information
@@ -846,7 +846,7 @@ contains
         ! be modified as the patch is laid out on the grid, but only in
         ! the case that smoothing of the ellipsoidal patch's boundary is
         ! enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the ellipsoid covers a particular cell in the
         ! domain and verifying whether the current patch has permission
@@ -868,12 +868,12 @@ contains
                                    (sqrt(((x_cc(i) - x_centroid)/a)**2 + &
                                          ((cart_y - y_centroid)/b)**2 + &
                                          ((cart_z - z_centroid)/c)**2) &
-                                    - 1d0))*(-0.5d0) + 0.5d0
+                                    - 1._wp))*(-0.5_wp) + 0.5_wp
                     end if
 
                     if ((((x_cc(i) - x_centroid)/a)**2 + &
                          ((cart_y - y_centroid)/b)**2 + &
-                         ((cart_z - z_centroid)/c)**2 <= 1d0 &
+                         ((cart_z - z_centroid)/c)**2 <= 1._wp &
                          .and. &
                          patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, k))) &
                         .or. &
@@ -886,7 +886,7 @@ contains
                         @:analytical()
 
                         ! Updating the patch identities bookkeeping variable
-                        if (1d0 - eta < 1d-16) patch_id_fp(i, j, k) = patch_id
+                        if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, k) = patch_id
                     end if
                 end do
             end do
@@ -914,11 +914,11 @@ contains
         logical, optional, intent(in) :: ib !< True if this patch is an immersed boundary
 
         integer :: i, j, k !< generic loop iterators
-        real(kind(0d0)) :: pi_inf, gamma, lit_gamma !< Equation of state parameters
+        real(wp) :: pi_inf, gamma, lit_gamma !< Equation of state parameters
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the rectangle's centroid and length information
         if (present(ib)) then
@@ -935,16 +935,16 @@ contains
 
         ! Computing the beginning and the end x- and y-coordinates of the
         ! rectangle based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
-        y_boundary%beg = y_centroid - 0.5d0*length_y
-        y_boundary%end = y_centroid + 0.5d0*length_y
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
+        y_boundary%beg = y_centroid - 0.5_wp*length_y
+        y_boundary%end = y_centroid + 0.5_wp*length_y
 
         ! Since the rectangular patch does not allow for its boundaries to
         ! be smoothed out, the pseudo volume fraction is set to 1 to ensure
         ! that only the current patch contributes to the fluid state in the
         ! cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the rectangle covers a particular cell in the
         ! domain and verifying whether the current patch has the permission
@@ -971,12 +971,12 @@ contains
                             if ((q_prim_vf(1)%sf(i, j, 0) < 1.e-10) .and. (model_eqns == 4)) then
                                 !zero density, reassign according to Tait EOS
                                 q_prim_vf(1)%sf(i, j, 0) = &
-                                    (((q_prim_vf(E_idx)%sf(i, j, 0) + pi_inf)/(pref + pi_inf))**(1d0/lit_gamma))* &
-                                    rhoref*(1d0 - q_prim_vf(alf_idx)%sf(i, j, 0))
+                                    (((q_prim_vf(E_idx)%sf(i, j, 0) + pi_inf)/(pref + pi_inf))**(1._wp/lit_gamma))* &
+                                    rhoref*(1._wp - q_prim_vf(alf_idx)%sf(i, j, 0))
                             end if
 
                             ! Updating the patch identities bookkeeping variable
-                            if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                            if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
 
                         end if
                     end if
@@ -1003,7 +1003,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< Generic loop operators
-        real(kind(0d0)) :: a, b, c
+        real(wp) :: a, b, c
 
         ! Transferring the centroid information of the line to be swept
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1019,7 +1019,7 @@ contains
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smoothing of the sweep line patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the region swept by the line covers a particular
         ! cell in the domain and verifying whether the current patch has the
@@ -1029,12 +1029,12 @@ contains
             do i = 0, m
 
                 if (patch_icpp(patch_id)%smoothen) then
-                    eta = 5d-1 + 5d-1*tanh(smooth_coeff/min(dx, dy) &
-                                           *(a*x_cc(i) + b*y_cc(j) + c) &
-                                           /sqrt(a**2 + b**2))
+                    eta = 5e-1_wp + 5e-1_wp*tanh(smooth_coeff/min(dx, dy) &
+                                                 *(a*x_cc(i) + b*y_cc(j) + c) &
+                                                 /sqrt(a**2 + b**2))
                 end if
 
-                if ((a*x_cc(i) + b*y_cc(j) + c >= 0d0 &
+                if ((a*x_cc(i) + b*y_cc(j) + c >= 0._wp &
                      .and. &
                      patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, 0))) &
                     .or. &
@@ -1046,7 +1046,7 @@ contains
                     @:analytical()
 
                     ! Updating the patch identities bookkeeping variable
-                    if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                    if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
                 end if
 
             end do
@@ -1068,12 +1068,12 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< generic loop iterators
-        real(kind(0d0)) :: pi_inf, gamma, lit_gamma !< equation of state parameters
-        real(kind(0d0)) :: L0, U0 !< Taylor Green Vortex parameters
+        real(wp) :: pi_inf, gamma, lit_gamma !< equation of state parameters
+        real(wp) :: L0, U0 !< Taylor Green Vortex parameters
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the patch's centroid and length information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1083,16 +1083,16 @@ contains
 
         ! Computing the beginning and the end x- and y-coordinates
         ! of the patch based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
-        y_boundary%beg = y_centroid - 0.5d0*length_y
-        y_boundary%end = y_centroid + 0.5d0*length_y
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
+        y_boundary%beg = y_centroid - 0.5_wp*length_y
+        y_boundary%end = y_centroid + 0.5_wp*length_y
 
         ! Since the patch doesn't allow for its boundaries to be
         ! smoothed out, the pseudo volume fraction is set to 1 to
         ! ensure that only the current patch contributes to the fluid
         ! state in the cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
         ! U0 is the characteristic velocity of the vortex
         U0 = patch_icpp(patch_id)%vel(1)
         ! L0 is the characteristic length of the vortex
@@ -1116,7 +1116,7 @@ contains
                     @:analytical()
 
                     ! Updating the patch identities bookkeeping variable
-                    if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                    if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
 
                     ! Assign Parameters =========================================================
                     q_prim_vf(mom_idx%beg)%sf(i, j, 0) = U0*sin(x_cc(i)/L0)*cos(y_cc(j)/L0)
@@ -1147,13 +1147,13 @@ contains
         ! Generic loop iterators
         integer :: i, j, k
         ! Placeholders for the cell boundary values
-        real(kind(0d0)) :: a, b, c, d, pi_inf, gamma, lit_gamma
+        real(wp) :: a, b, c, d, pi_inf, gamma, lit_gamma
 
         @:Hardcoded1DVariables()
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the patch's centroid and length information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1161,14 +1161,14 @@ contains
 
         ! Computing the beginning and the end x- and y-coordinates
         ! of the patch based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
 
         ! Since the patch doesn't allow for its boundaries to be
         ! smoothed out, the pseudo volume fraction is set to 1 to
         ! ensure that only the current patch contributes to the fluid
         ! state in the cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the line segment covers a particular cell in the
         ! domain and verifying whether the current patch has the permission
@@ -1185,7 +1185,7 @@ contains
                 @:Hardcoded1D()
 
                 ! Updating the patch identities bookkeeping variable
-                if (1d0 - eta < 1d-16) patch_id_fp(i, 0, 0) = patch_id
+                if (1._wp - eta < 1e-16_wp) patch_id_fp(i, 0, 0) = patch_id
 
             end if
         end do
@@ -1207,11 +1207,11 @@ contains
         ! Generic loop iterators
         integer :: i, j, k
         ! Placeholders for the cell boundary values
-        real(kind(0d0)) :: fac, a, b, c, d, pi_inf, gamma, lit_gamma
+        real(wp) :: fac, a, b, c, d, pi_inf, gamma, lit_gamma
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the patch's centroid and length information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1219,14 +1219,14 @@ contains
 
         ! Computing the beginning and the end x- and y-coordinates
         ! of the patch based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
 
         ! Since the patch doesn't allow for its boundaries to be
         ! smoothed out, the pseudo volume fraction is set to 1 to
         ! ensure that only the current patch contributes to the fluid
         ! state in the cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the line segment covers a particular cell in the
         ! domain and verifying whether the current patch has the permission
@@ -1259,15 +1259,15 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< generic loop iterators
-        real(kind(0d0)) :: a, b, c, d !< placeholderrs for the cell boundary values
-        real(kind(0d0)) :: pi_inf, gamma, lit_gamma !< equation of state parameters
-        real(kind(0d0)) :: l, U0 !< Taylor Green Vortex parameters
+        real(wp) :: a, b, c, d !< placeholderrs for the cell boundary values
+        real(wp) :: pi_inf, gamma, lit_gamma !< equation of state parameters
+        real(wp) :: l, U0 !< Taylor Green Vortex parameters
 
         @:Hardcoded2DVariables()
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the patch's centroid and length information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1277,18 +1277,18 @@ contains
 
         ! Computing the beginning and the end x- and y-coordinates
         ! of the patch based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
-        y_boundary%beg = y_centroid - 0.5d0*length_y
-        y_boundary%end = y_centroid + 0.5d0*length_y
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
+        y_boundary%beg = y_centroid - 0.5_wp*length_y
+        y_boundary%end = y_centroid + 0.5_wp*length_y
 
         ! Since the patch doesn't allow for its boundaries to be
         ! smoothed out, the pseudo volume fraction is set to 1 to
         ! ensure that only the current patch contributes to the fluid
         ! state in the cells that this patch covers.
-        eta = 1d0
-        l = 1d0
-        U0 = 0.1
+        eta = 1._wp
+        l = 1._wp
+        U0 = 0.1_wp
         ! Checking whether the patch covers a particular cell in the
         ! domain and verifying whether the current patch has the
         ! permission to write to that cell. If both queries check out,
@@ -1308,7 +1308,7 @@ contains
 
                     @:Hardcoded2D()
                     ! Updating the patch identities bookkeeping variable
-                    if (1d0 - eta < 1d-16) patch_id_fp(i, j, 0) = patch_id
+                    if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, 0) = patch_id
 
                 end if
             end do
@@ -1328,13 +1328,13 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< generic loop iterators
-        real(kind(0d0)) :: pi_inf, gamma, lit_gamma !< equation of state parameters
+        real(wp) :: pi_inf, gamma, lit_gamma !< equation of state parameters
 
         @:Hardcoded3DVariables()
 
         pi_inf = fluid_pp(1)%pi_inf
         gamma = fluid_pp(1)%gamma
-        lit_gamma = (1d0 + gamma)/gamma
+        lit_gamma = (1._wp + gamma)/gamma
 
         ! Transferring the patch's centroid and length information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1346,18 +1346,18 @@ contains
 
         ! Computing the beginning and the end x-, y- and z-coordinates of
         ! the patch based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
-        y_boundary%beg = y_centroid - 0.5d0*length_y
-        y_boundary%end = y_centroid + 0.5d0*length_y
-        z_boundary%beg = z_centroid - 0.5d0*length_z
-        z_boundary%end = z_centroid + 0.5d0*length_z
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
+        y_boundary%beg = y_centroid - 0.5_wp*length_y
+        y_boundary%end = y_centroid + 0.5_wp*length_y
+        z_boundary%beg = z_centroid - 0.5_wp*length_z
+        z_boundary%end = z_centroid + 0.5_wp*length_z
 
         ! Since the analytical patch does not allow for its boundaries to get
         ! smoothed out, the pseudo volume fraction is set to 1 to make sure
         ! that only the current patch contributes to the fluid state in the
         ! cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the patch covers a particular cell in the domain
         ! and verifying whether the current patch has permission to write to
@@ -1390,7 +1390,7 @@ contains
                         @:Hardcoded3D()
 
                         ! Updating the patch identities bookkeeping variable
-                        if (1d0 - eta < 1d-16) patch_id_fp(i, j, k) = patch_id
+                        if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, k) = patch_id
 
                     end if
 
@@ -1412,9 +1412,9 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< generic loop iterators
-        real(kind(0d0)) :: radius, epsilon, beta
-        complex(kind(0d0)) :: cmplx_i = (0d0, 1d0)
-        complex(kind(0d0)) :: H
+        real(wp) :: radius, epsilon, beta
+        complex(wp) :: cmplx_i = (0._wp, 1._wp)
+        complex(wp) :: H
 
         ! Transferring the patch's centroid and radius information
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1428,7 +1428,7 @@ contains
         ! smoothed out, the pseudo volume fraction is set to 1 to make sure
         ! that only the current patch contributes to the fluid state in the
         ! cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the patch covers a particular cell in the domain
         ! and verifying whether the current patch has permission to write to
@@ -1454,72 +1454,72 @@ contains
 
                         call s_convert_cylindrical_to_spherical_coord(x_cc(i), y_cc(j))
 
-                        if (epsilon == 1d0) then
-                            if (beta == 0d0) then
-                                H = 5d-1*sqrt(3d0/pi)*cos(sph_phi)
-                            elseif (beta == 1d0) then
-                                H = -5d-1*sqrt(3d0/(2d0*pi))*exp(cmplx_i*z_cc(k))*sin(sph_phi)
+                        if (epsilon == 1._wp) then
+                            if (beta == 0._wp) then
+                                H = 5e-1_wp*sqrt(3._wp/pi)*cos(sph_phi)
+                            elseif (beta == 1._wp) then
+                                H = -5e-1_wp*sqrt(3._wp/(2._wp*pi))*exp(cmplx_i*z_cc(k))*sin(sph_phi)
                             end if
-                        elseif (epsilon == 2d0) then
-                            if (beta == 0d0) then
-                                H = 25d-2*sqrt(5d0/pi)*(3d0*cos(sph_phi)**2 - 1d0)
-                            elseif (beta == 1d0) then
-                                H = -5d-1*sqrt(15d0/(2d0*pi))*exp(cmplx_i*z_cc(k))*sin(sph_phi)*cos(sph_phi)
-                            elseif (beta == 2d0) then
-                                H = 25d-2*sqrt(15d0/(2d0*pi))*exp(2d0*cmplx_i*z_cc(k))*sin(sph_phi)**2
+                        elseif (epsilon == 2._wp) then
+                            if (beta == 0._wp) then
+                                H = 25e-2_wp*sqrt(5._wp/pi)*(3._wp*cos(sph_phi)**2 - 1._wp)
+                            elseif (beta == 1._wp) then
+                                H = -5e-1_wp*sqrt(15._wp/(2._wp*pi))*exp(cmplx_i*z_cc(k))*sin(sph_phi)*cos(sph_phi)
+                            elseif (beta == 2._wp) then
+                                H = 25e-2_wp*sqrt(15._wp/(2._wp*pi))*exp(2._wp*cmplx_i*z_cc(k))*sin(sph_phi)**2
                             end if
-                        elseif (epsilon == 3d0) then
-                            if (beta == 0d0) then
-                                H = 25d-2*sqrt(7d0/pi)*(5d0*cos(sph_phi)**3d0 - 3d0*cos(sph_phi))
-                            elseif (beta == 1d0) then
-                                H = -125d-3*sqrt(21d0/pi)*exp(cmplx_i*z_cc(k))*sin(sph_phi)* &
-                                    (5d0*cos(sph_phi)**2 - 1d0)
-                            elseif (beta == 2d0) then
-                                H = 25d-2*sqrt(105d0/(2d0*pi))*exp(2d0*cmplx_i*z_cc(k))* &
+                        elseif (epsilon == 3._wp) then
+                            if (beta == 0._wp) then
+                                H = 25e-2_wp*sqrt(7._wp/pi)*(5._wp*cos(sph_phi)**3._wp - 3._wp*cos(sph_phi))
+                            elseif (beta == 1._wp) then
+                                H = -125e-3_wp*sqrt(21._wp/pi)*exp(cmplx_i*z_cc(k))*sin(sph_phi)* &
+                                    (5._wp*cos(sph_phi)**2 - 1._wp)
+                            elseif (beta == 2._wp) then
+                                H = 25e-2_wp*sqrt(105._wp/(2._wp*pi))*exp(2._wp*cmplx_i*z_cc(k))* &
                                     sin(sph_phi)**2*cos(sph_phi)
-                            elseif (beta == 3d0) then
-                                H = -125d-3*sqrt(35d0/pi)*exp(3d0*cmplx_i*z_cc(k))*sin(sph_phi)**3d0
+                            elseif (beta == 3._wp) then
+                                H = -125e-3_wp*sqrt(35._wp/pi)*exp(3._wp*cmplx_i*z_cc(k))*sin(sph_phi)**3._wp
                             end if
-                        elseif (epsilon == 4d0) then
-                            if (beta == 0d0) then
-                                H = 3d0/16d0*sqrt(1d0/pi)*(35d0*cos(sph_phi)**4d0 - &
-                                                           3d1*cos(sph_phi)**2 + 3d0)
-                            elseif (beta == 1d0) then
-                                H = -3d0/8d0*sqrt(5d0/pi)*exp(cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)*(7d0*cos(sph_phi)**3d0 - 3d0*cos(sph_phi))
-                            elseif (beta == 2d0) then
-                                H = 3d0/8d0*sqrt(5d0/(2d0*pi))*exp(2d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**2*(7d0*cos(sph_phi)**2 - 1d0)
-                            elseif (beta == 3d0) then
-                                H = -3d0/8d0*sqrt(35d0/pi)*exp(3d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**3d0*cos(sph_phi)
-                            elseif (beta == 4d0) then
-                                H = 3d0/16d0*sqrt(35d0/(2d0*pi))*exp(4d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**4d0
+                        elseif (epsilon == 4._wp) then
+                            if (beta == 0._wp) then
+                                H = 3._wp/16._wp*sqrt(1._wp/pi)*(35._wp*cos(sph_phi)**4._wp - &
+                                                                 3e1_wp*cos(sph_phi)**2 + 3._wp)
+                            elseif (beta == 1._wp) then
+                                H = -3._wp/8._wp*sqrt(5._wp/pi)*exp(cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)*(7._wp*cos(sph_phi)**3._wp - 3._wp*cos(sph_phi))
+                            elseif (beta == 2._wp) then
+                                H = 3._wp/8._wp*sqrt(5._wp/(2._wp*pi))*exp(2._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**2*(7._wp*cos(sph_phi)**2 - 1._wp)
+                            elseif (beta == 3._wp) then
+                                H = -3._wp/8._wp*sqrt(35._wp/pi)*exp(3._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**3._wp*cos(sph_phi)
+                            elseif (beta == 4._wp) then
+                                H = 3._wp/16._wp*sqrt(35._wp/(2._wp*pi))*exp(4._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**4._wp
                             end if
-                        elseif (epsilon == 5d0) then
-                            if (beta == 0d0) then
-                                H = 1d0/16d0*sqrt(11d0/pi)*(63d0*cos(sph_phi)**5d0 - &
-                                                            7d1*cos(sph_phi)**3d0 + 15d0*cos(sph_phi))
-                            elseif (beta == 1d0) then
-                                H = -1d0/16d0*sqrt(165d0/(2d0*pi))*exp(cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)*(21d0*cos(sph_phi)**4d0 - 14d0*cos(sph_phi)**2 + 1d0)
-                            elseif (beta == 2d0) then
-                                H = 125d-3*sqrt(1155d0/(2d0*pi))*exp(2d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**2*(3d0*cos(sph_phi)**3d0 - cos(sph_phi))
-                            elseif (beta == 3d0) then
-                                H = -1d0/32d0*sqrt(385d0/pi)*exp(3d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**3d0*(9d0*cos(sph_phi)**2 - 1d0)
-                            elseif (beta == 4d0) then
-                                H = 3d0/16d0*sqrt(385d0/(2d0*pi))*exp(4d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**4d0*cos(sph_phi)
-                            elseif (beta == 5d0) then
-                                H = -3d0/32d0*sqrt(77d0/pi)*exp(5d0*cmplx_i*z_cc(k))* &
-                                    sin(sph_phi)**5d0
+                        elseif (epsilon == 5._wp) then
+                            if (beta == 0._wp) then
+                                H = 1._wp/16._wp*sqrt(11._wp/pi)*(63._wp*cos(sph_phi)**5._wp - &
+                                                                  7e1_wp*cos(sph_phi)**3._wp + 15._wp*cos(sph_phi))
+                            elseif (beta == 1._wp) then
+                                H = -1._wp/16._wp*sqrt(165._wp/(2._wp*pi))*exp(cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)*(21._wp*cos(sph_phi)**4._wp - 14._wp*cos(sph_phi)**2 + 1._wp)
+                            elseif (beta == 2._wp) then
+                                H = 125e-3_wp*sqrt(1155._wp/(2._wp*pi))*exp(2._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**2*(3._wp*cos(sph_phi)**3._wp - cos(sph_phi))
+                            elseif (beta == 3._wp) then
+                                H = -1._wp/32._wp*sqrt(385._wp/pi)*exp(3._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**3._wp*(9._wp*cos(sph_phi)**2 - 1._wp)
+                            elseif (beta == 4._wp) then
+                                H = 3._wp/16._wp*sqrt(385._wp/(2._wp*pi))*exp(4._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**4._wp*cos(sph_phi)
+                            elseif (beta == 5._wp) then
+                                H = -3._wp/32._wp*sqrt(77._wp/pi)*exp(5._wp*cmplx_i*z_cc(k))* &
+                                    sin(sph_phi)**5._wp
                             end if
                         end if
 
-                        q_prim_vf(adv_idx%beg)%sf(i, j, k) = 1d0 - abs(real(H, kind(0d0)))
+                        q_prim_vf(adv_idx%beg)%sf(i, j, k) = 1._wp - abs(real(H, wp))
 
                     end if
 
@@ -1547,9 +1547,9 @@ contains
 
         ! Generic loop iterators
         integer :: i, j, k !< generic loop iterators
-        real(kind(0d0)) :: radius
+        real(wp) :: radius
 
-        real(kind(0d0)) :: radius_pressure, pressure_bubble, pressure_inf !<
+        real(wp) :: radius_pressure, pressure_bubble, pressure_inf !<
             !! Variables to initialize the pressure field that corresponds to the
             !! bubble-collapse test case found in Tiwari et al. (2013)
 
@@ -1572,7 +1572,7 @@ contains
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smoothing of the spherical patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the sphere covers a particular cell in the domain
         ! and verifying whether the current patch has permission to write to
@@ -1612,7 +1612,7 @@ contains
                                            (sqrt((x_cc(i) - x_centroid)**2 &
                                                  + (cart_y - y_centroid)**2 &
                                                  + (cart_z - z_centroid)**2) &
-                                            - radius))*(-0.5d0) + 0.5d0
+                                            - radius))*(-0.5_wp) + 0.5_wp
                             end if
                         end if
                     end if
@@ -1662,18 +1662,18 @@ contains
 
         ! Computing the beginning and the end x-, y- and z-coordinates of
         ! the cuboid based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
-        y_boundary%beg = y_centroid - 0.5d0*length_y
-        y_boundary%end = y_centroid + 0.5d0*length_y
-        z_boundary%beg = z_centroid - 0.5d0*length_z
-        z_boundary%end = z_centroid + 0.5d0*length_z
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
+        y_boundary%beg = y_centroid - 0.5_wp*length_y
+        y_boundary%end = y_centroid + 0.5_wp*length_y
+        z_boundary%beg = z_centroid - 0.5_wp*length_z
+        z_boundary%end = z_centroid + 0.5_wp*length_z
 
         ! Since the cuboidal patch does not allow for its boundaries to get
         ! smoothed out, the pseudo volume fraction is set to 1 to make sure
         ! that only the current patch contributes to the fluid state in the
         ! cells that this patch covers.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the cuboid covers a particular cell in the domain
         ! and verifying whether the current patch has permission to write to
@@ -1709,7 +1709,7 @@ contains
                                 @:analytical()
 
                                 ! Updating the patch identities bookkeeping variable
-                                if (1d0 - eta < 1d-16) patch_id_fp(i, j, k) = patch_id
+                                if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, k) = patch_id
 
                             end if
                         end if
@@ -1740,7 +1740,7 @@ contains
         logical, optional, intent(in) :: ib   !< True if this patch is an immersed boundary
 
         integer :: i, j, k !< Generic loop iterators
-        real(kind(0d0)) :: radius
+        real(wp) :: radius
 
         ! Transferring the cylindrical patch's centroid, length, radius,
         ! smoothing patch identity and smoothing coefficient information
@@ -1767,17 +1767,17 @@ contains
 
         ! Computing the beginning and the end x-, y- and z-coordinates of
         ! the cylinder based on its centroid and lengths
-        x_boundary%beg = x_centroid - 0.5d0*length_x
-        x_boundary%end = x_centroid + 0.5d0*length_x
-        y_boundary%beg = y_centroid - 0.5d0*length_y
-        y_boundary%end = y_centroid + 0.5d0*length_y
-        z_boundary%beg = z_centroid - 0.5d0*length_z
-        z_boundary%end = z_centroid + 0.5d0*length_z
+        x_boundary%beg = x_centroid - 0.5_wp*length_x
+        x_boundary%end = x_centroid + 0.5_wp*length_x
+        y_boundary%beg = y_centroid - 0.5_wp*length_y
+        y_boundary%end = y_centroid + 0.5_wp*length_y
+        z_boundary%beg = z_centroid - 0.5_wp*length_z
+        z_boundary%end = z_centroid + 0.5_wp*length_z
 
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smearing of the cylindrical patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the cylinder covers a particular cell in the
         ! domain and verifying whether the current patch has the permission
@@ -1825,7 +1825,7 @@ contains
                                 @:analytical()
 
                                 ! Updating the patch identities bookkeeping variable
-                                if (1d0 - eta < 1d-16) patch_id_fp(i, j, k) = patch_id
+                                if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, k) = patch_id
                             end if
 
                             if (patch_icpp(patch_id)%smoothen) then
@@ -1833,17 +1833,17 @@ contains
                                     eta = tanh(smooth_coeff/min(dy, dz)* &
                                                (sqrt((cart_y - y_centroid)**2 &
                                                      + (cart_z - z_centroid)**2) &
-                                                - radius))*(-0.5d0) + 0.5d0
+                                                - radius))*(-0.5_wp) + 0.5_wp
                                 elseif (.not. f_is_default(length_y)) then
                                     eta = tanh(smooth_coeff/min(dx, dz)* &
                                                (sqrt((x_cc(i) - x_centroid)**2 &
                                                      + (cart_z - z_centroid)**2) &
-                                                - radius))*(-0.5d0) + 0.5d0
+                                                - radius))*(-0.5_wp) + 0.5_wp
                                 else
                                     eta = tanh(smooth_coeff/min(dx, dy)* &
                                                (sqrt((x_cc(i) - x_centroid)**2 &
                                                      + (cart_y - y_centroid)**2) &
-                                                - radius))*(-0.5d0) + 0.5d0
+                                                - radius))*(-0.5_wp) + 0.5_wp
                                 end if
                             end if
                         end if
@@ -1871,7 +1871,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: q_prim_vf
 
         integer :: i, j, k !< Generic loop iterators
-        real(kind(0d0)) :: a, b, c, d
+        real(wp) :: a, b, c, d
 
         ! Transferring the centroid information of the plane to be swept
         x_centroid = patch_icpp(patch_id)%x_centroid
@@ -1889,7 +1889,7 @@ contains
         ! Initializing the pseudo volume fraction value to 1. The value will
         ! be modified as the patch is laid out on the grid, but only in the
         ! case that smearing of the sweep plane patch's boundary is enabled.
-        eta = 1d0
+        eta = 1._wp
 
         ! Checking whether the region swept by the plane covers a particular
         ! cell in the domain and verifying whether the current patch has the
@@ -1907,14 +1907,14 @@ contains
                     end if
 
                     if (patch_icpp(patch_id)%smoothen) then
-                        eta = 5d-1 + 5d-1*tanh(smooth_coeff/min(dx, dy, dz) &
-                                               *(a*x_cc(i) + &
-                                                 b*cart_y + &
-                                                 c*cart_z + d) &
-                                               /sqrt(a**2 + b**2 + c**2))
+                        eta = 5e-1_wp + 5e-1_wp*tanh(smooth_coeff/min(dx, dy, dz) &
+                                                     *(a*x_cc(i) + &
+                                                       b*cart_y + &
+                                                       c*cart_z + d) &
+                                                     /sqrt(a**2 + b**2 + c**2))
                     end if
 
-                    if ((a*x_cc(i) + b*cart_y + c*cart_z + d >= 0d0 &
+                    if ((a*x_cc(i) + b*cart_y + c*cart_z + d >= 0._wp &
                          .and. &
                          patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, k))) &
                         .or. &
@@ -1927,7 +1927,7 @@ contains
                         @:analytical()
 
                         ! Updating the patch identities bookkeeping variable
-                        if (1d0 - eta < 1d-16) patch_id_fp(i, j, k) = patch_id
+                        if (1._wp - eta < 1e-16_wp) patch_id_fp(i, j, k) = patch_id
                     end if
 
                 end do
@@ -1953,11 +1953,11 @@ contains
         type(levelset_field), optional, intent(inout) :: STL_levelset !< Levelset determined by models
         type(levelset_norm_field), optional, intent(inout) :: STL_levelset_norm !< Levelset_norm determined by models
         logical, optional, intent(in) :: ib   !< True if this patch is an immersed boundary
-        real(kind(0d0)) :: normals(1:3) !< Boundary normal buffer
+        real(wp) :: normals(1:3) !< Boundary normal buffer
         integer :: boundary_vertex_count, boundary_edge_count, total_vertices !< Boundary vertex
-        real(kind(0d0)), allocatable, dimension(:, :, :) :: boundary_v !< Boundary vertex buffer
-        real(kind(0d0)), allocatable, dimension(:, :) :: interpolated_boundary_v !< Interpolated vertex buffer
-        real(kind(0d0)) :: distance !< Levelset distance buffer
+        real(wp), allocatable, dimension(:, :, :) :: boundary_v !< Boundary vertex buffer
+        real(wp), allocatable, dimension(:, :) :: interpolated_boundary_v !< Interpolated vertex buffer
+        real(wp) :: distance !< Levelset distance buffer
         logical :: interpolate !< Logical variable to determine whether or not the model should be interpolated
 
         integer :: i, j, k !< Generic loop iterators
@@ -1968,7 +1968,7 @@ contains
 
         t_vec3 :: point
 
-        real(kind(0d0)) :: grid_mm(1:3, 1:2)
+        real(wp) :: grid_mm(1:3, 1:2)
 
         integer :: cell_num
         integer :: ncells
@@ -2044,23 +2044,23 @@ contains
 
         if (proc_rank == 0) then
             write (*, "(A, 3(2X, F20.10))") "    > Model:  Min:", bbox%min(1:3)
-            write (*, "(A, 3(2X, F20.10))") "    >         Cen:", (bbox%min(1:3) + bbox%max(1:3))/2d0
+            write (*, "(A, 3(2X, F20.10))") "    >         Cen:", (bbox%min(1:3) + bbox%max(1:3))/2._wp
             write (*, "(A, 3(2X, F20.10))") "    >         Max:", bbox%max(1:3)
 
             !call s_model_write("__out__.stl", model)
             !call s_model_write("__out__.obj", model)
 
-            grid_mm(1, :) = (/minval(x_cc) - 0d5*dx, maxval(x_cc) + 0d5*dx/)
-            grid_mm(2, :) = (/minval(y_cc) - 0d5*dy, maxval(y_cc) + 0d5*dy/)
+            grid_mm(1, :) = (/minval(x_cc) - 0e5_wp*dx, maxval(x_cc) + 0e5_wp*dx/)
+            grid_mm(2, :) = (/minval(y_cc) - 0e5_wp*dy, maxval(y_cc) + 0e5_wp*dy/)
 
             if (p > 0) then
-                grid_mm(3, :) = (/minval(z_cc) - 0d5*dz, maxval(z_cc) + 0d5*dz/)
+                grid_mm(3, :) = (/minval(z_cc) - 0e5_wp*dz, maxval(z_cc) + 0e5_wp*dz/)
             else
-                grid_mm(3, :) = (/0d0, 0d0/)
+                grid_mm(3, :) = (/0._wp, 0._wp/)
             end if
 
             write (*, "(A, 3(2X, F20.10))") "    > Domain: Min:", grid_mm(:, 1)
-            write (*, "(A, 3(2X, F20.10))") "    >         Cen:", (grid_mm(:, 1) + grid_mm(:, 2))/2d0
+            write (*, "(A, 3(2X, F20.10))") "    >         Cen:", (grid_mm(:, 1) + grid_mm(:, 2))/2._wp
             write (*, "(A, 3(2X, F20.10))") "    >         Max:", grid_mm(:, 2)
         end if
 
@@ -2074,7 +2074,7 @@ contains
                             nint(100*real(cell_num)/ncells), "%"
                     end if
 
-                    point = (/x_cc(i), y_cc(j), 0d0/)
+                    point = (/x_cc(i), y_cc(j), 0._wp/)
                     if (p > 0) then
                         point(3) = z_cc(k)
                     end if
@@ -2164,13 +2164,13 @@ contains
                     else
                         if (patch_icpp(patch_id)%smoothen) then
                             if (eta > patch_icpp(patch_id)%model_threshold) then
-                                eta = 1d0
+                                eta = 1._wp
                             end if
                         else
                             if (eta > patch_icpp(patch_id)%model_threshold) then
-                                eta = 1d0
+                                eta = 1._wp
                             else
-                                eta = 0d0
+                                eta = 0._wp
                             end if
                         end if
                         call s_assign_patch_primitive_variables(patch_id, i, j, k, &
@@ -2194,7 +2194,7 @@ contains
     subroutine s_convert_cylindrical_to_cartesian_coord(cyl_y, cyl_z)
         !$acc routine seq
 
-        real(kind(0d0)), intent(in) :: cyl_y, cyl_z
+        real(wp), intent(in) :: cyl_y, cyl_z
 
         cart_y = cyl_y*sin(cyl_z)
         cart_z = cyl_y*cos(cyl_z)
@@ -2217,7 +2217,7 @@ contains
     subroutine s_convert_cylindrical_to_spherical_coord(cyl_x, cyl_y)
         !$acc routine seq
 
-        real(kind(0d0)), intent(IN) :: cyl_x, cyl_y
+        real(wp), intent(IN) :: cyl_x, cyl_y
 
         sph_phi = atan(cyl_y/cyl_x)
 
@@ -2229,13 +2229,13 @@ contains
     !! @param a Starting position
     function f_r(myth, offset, a)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: myth, offset, a
-        real(kind(0d0)) :: b
-        real(kind(0d0)) :: f_r
+        real(wp), intent(in) :: myth, offset, a
+        real(wp) :: b
+        real(wp) :: f_r
 
         !r(th) = a + b*th
 
-        b = 2.d0*a/(2.d0*pi)
+        b = 2._wp*a/(2._wp*pi)
         f_r = a + b*myth + offset
     end function f_r
 
diff --git a/src/pre_process/m_perturbation.fpp b/src/pre_process/m_perturbation.fpp
index 0247043dc..8137365d2 100644
--- a/src/pre_process/m_perturbation.fpp
+++ b/src/pre_process/m_perturbation.fpp
@@ -54,9 +54,9 @@ contains
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
         integer :: i, j, k, l !< generic loop operators
 
-        real(kind(0d0)) :: perturb_alpha
-        real(kind(0d0)) :: alpha_unadv
-        real(kind(0d0)) :: rand_real
+        real(wp) :: perturb_alpha
+        real(wp) :: alpha_unadv
+        real(wp) :: rand_real
         call random_seed()
 
         do k = 0, p
@@ -67,8 +67,8 @@ contains
                     perturb_alpha = q_prim_vf(E_idx + perturb_sph_fluid)%sf(i, j, k)
 
                     ! Perturb partial density fields to match perturbed volume fraction fields
-                    !    IF ((perturb_alpha >= 25d-2) .AND. (perturb_alpha <= 75d-2)) THEN
-                    if ((perturb_alpha /= 0d0) .and. (perturb_alpha /= 1d0)) then
+                    !    IF ((perturb_alpha >= 25e-2_wp) .AND. (perturb_alpha <= 75e-2_wp)) THEN
+                    if ((perturb_alpha /= 0._wp) .and. (perturb_alpha /= 1._wp)) then
 
                         ! Derive new partial densities
                         do l = 1, num_fluids
@@ -86,8 +86,8 @@ contains
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
         integer :: i, j, k, l !<  generic loop iterators
 
-        real(kind(0d0)) :: perturb_alpha
-        real(kind(0d0)) :: rand_real
+        real(wp) :: perturb_alpha
+        real(wp) :: rand_real
         call random_seed()
 
         ! Perturb partial density or velocity of surrounding flow by some random small amount of noise
@@ -97,10 +97,10 @@ contains
                     perturb_alpha = q_prim_vf(E_idx + perturb_flow_fluid)%sf(i, j, k)
                     call random_number(rand_real)
                     rand_real = rand_real*perturb_flow_mag
-                    q_prim_vf(mom_idx%beg)%sf(i, j, k) = (1.d0 + rand_real)*q_prim_vf(mom_idx%beg)%sf(i, j, k)
+                    q_prim_vf(mom_idx%beg)%sf(i, j, k) = (1._wp + rand_real)*q_prim_vf(mom_idx%beg)%sf(i, j, k)
                     q_prim_vf(mom_idx%end)%sf(i, j, k) = rand_real*q_prim_vf(mom_idx%beg)%sf(i, j, k)
                     if (bubbles) then
-                        q_prim_vf(alf_idx)%sf(i, j, k) = (1.d0 + rand_real)*q_prim_vf(alf_idx)%sf(i, j, k)
+                        q_prim_vf(alf_idx)%sf(i, j, k) = (1._wp + rand_real)*q_prim_vf(alf_idx)%sf(i, j, k)
                     end if
                 end do
             end do
@@ -116,41 +116,41 @@ contains
         !!              (2,2), (2,-2), (1,1), (1,-1) areadded on top of 2D waves.
     subroutine s_superposition_instability_wave(q_prim_vf)
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(mixlayer_nvar, 0:m, 0:n, 0:p) :: wave, wave1, wave2, wave_tmp
-        real(kind(0d0)) :: uratio, Ldomain
+        real(wp), dimension(mixlayer_nvar, 0:m, 0:n, 0:p) :: wave, wave1, wave2, wave_tmp
+        real(wp) :: uratio, Ldomain
         integer :: i, j, k, q
 
-        uratio = 1d0/patch_icpp(1)%vel(1)
+        uratio = 1._wp/patch_icpp(1)%vel(1)
         Ldomain = mixlayer_domain*patch_icpp(1)%length_y
 
-        wave = 0d0
-        wave1 = 0d0
-        wave2 = 0d0
+        wave = 0._wp
+        wave1 = 0._wp
+        wave2 = 0._wp
 
         ! Compute 2D waves
-        call s_instability_wave(2*pi*4.0/Ldomain, 0d0, wave_tmp, 0d0)
+        call s_instability_wave(2*pi*4.0_wp/Ldomain, 0._wp, wave_tmp, 0._wp)
         wave1 = wave1 + wave_tmp
-        call s_instability_wave(2*pi*2.0/Ldomain, 0d0, wave_tmp, 0d0)
+        call s_instability_wave(2*pi*2.0_wp/Ldomain, 0._wp, wave_tmp, 0._wp)
         wave1 = wave1 + wave_tmp
-        call s_instability_wave(2*pi*1.0/Ldomain, 0d0, wave_tmp, 0d0)
+        call s_instability_wave(2*pi*1.0_wp/Ldomain, 0._wp, wave_tmp, 0._wp)
         wave1 = wave1 + wave_tmp
-        wave = wave1*0.05
+        wave = wave1*0.05_wp
 
         if (p > 0) then
             ! Compute 3D waves with phase shifts.
-            call s_instability_wave(2*pi*4.0/Ldomain, 2*pi*4.0/Ldomain, wave_tmp, 2*pi*11d0/31d0)
+            call s_instability_wave(2*pi*4.0_wp/Ldomain, 2*pi*4.0_wp/Ldomain, wave_tmp, 2*pi*11._wp/31._wp)
             wave2 = wave2 + wave_tmp
-            call s_instability_wave(2*pi*2.0/Ldomain, 2*pi*2.0/Ldomain, wave_tmp, 2*pi*13d0/31d0)
+            call s_instability_wave(2*pi*2.0_wp/Ldomain, 2*pi*2.0_wp/Ldomain, wave_tmp, 2*pi*13._wp/31._wp)
             wave2 = wave2 + wave_tmp
-            call s_instability_wave(2*pi*1.0/Ldomain, 2*pi*1.0/Ldomain, wave_tmp, 2*pi*17d0/31d0)
+            call s_instability_wave(2*pi*1.0_wp/Ldomain, 2*pi*1.0_wp/Ldomain, wave_tmp, 2*pi*17._wp/31._wp)
             wave2 = wave2 + wave_tmp
-            call s_instability_wave(2*pi*4.0/Ldomain, -2*pi*4.0/Ldomain, wave_tmp, 2*pi*19d0/31d0)
+            call s_instability_wave(2*pi*4.0_wp/Ldomain, -2*pi*4.0_wp/Ldomain, wave_tmp, 2*pi*19._wp/31._wp)
             wave2 = wave2 + wave_tmp
-            call s_instability_wave(2*pi*2.0/Ldomain, -2*pi*2.0/Ldomain, wave_tmp, 2*pi*23d0/31d0)
+            call s_instability_wave(2*pi*2.0_wp/Ldomain, -2*pi*2.0_wp/Ldomain, wave_tmp, 2*pi*23._wp/31._wp)
             wave2 = wave2 + wave_tmp
-            call s_instability_wave(2*pi*1.0/Ldomain, -2*pi*1.0/Ldomain, wave_tmp, 2*pi*29d0/31d0)
+            call s_instability_wave(2*pi*1.0_wp/Ldomain, -2*pi*1.0_wp/Ldomain, wave_tmp, 2*pi*29._wp/31._wp)
             wave2 = wave2 + wave_tmp
-            wave = wave + 0.15*wave2
+            wave = wave + 0.15_wp*wave2
         end if
 
         ! Superpose velocity perturbuations (instability waves) to the velocity field
@@ -178,22 +178,22 @@ contains
 
     !>  This subroutine computes equilibrium bubble radius of the perturbed pressure field
     subroutine s_compute_equilibrium_state(fP, fR0, fR)
-        real(kind(0d0)), intent(in) :: fP, fR0
-        real(kind(0d0)), intent(inout) :: fR
-        real(kind(0d0)) :: f0, f1
-        real(kind(0d0)) :: gam_b
+        real(wp), intent(in) :: fP, fR0
+        real(wp), intent(inout) :: fR
+        real(wp) :: f0, f1
+        real(wp) :: gam_b
         integer :: ii, jj
 
-        gam_b = 1d0 + 1d0/fluid_pp(num_fluids + 1)%gamma
+        gam_b = 1._wp + 1._wp/fluid_pp(num_fluids + 1)%gamma
 
         ! Loop
         ii = 1
         do while (.true.)
 
-            f0 = (Ca + 2d0/Web)*(fR0/fR)**(3d0*gam_b) - 2d0/(Web*fR) + 1d0 - Ca - fP
-            f1 = -3d0*gam_b*(Ca + 2d0/Web)*(fR0/fR)**(3d0*gam_b + 1d0) + 2d0/(Web*fR**2d0)
+            f0 = (Ca + 2._wp/Web)*(fR0/fR)**(3._wp*gam_b) - 2._wp/(Web*fR) + 1._wp - Ca - fP
+            f1 = -3._wp*gam_b*(Ca + 2._wp/Web)*(fR0/fR)**(3._wp*gam_b + 1._wp) + 2._wp/(Web*fR**2._wp)
 
-            if (abs(f0) <= 1e-10) then
+            if (abs(f0) <= 1e-10_wp) then
                 ! Converged
                 exit
             else
@@ -205,7 +205,7 @@ contains
             if (ieee_is_nan(f0) .or. &
                 ieee_is_nan(f1) .or. &
                 ii > 1000 .or. &
-                fR < 0d0) then
+                fR < 0._wp) then
 
                 print *, "Failed to compute equilibrium radius"
 
@@ -224,31 +224,31 @@ contains
         !!              Euler equations with parallel mean flow assumption
         !!              (See Sandham 1989 PhD thesis for details).
     subroutine s_instability_wave(alpha, beta, wave, shift)
-        real(kind(0d0)), intent(in) :: alpha, beta !<  spatial wavenumbers
-        real(kind(0d0)), dimension(mixlayer_nvar, 0:m, 0:n, 0:p), intent(inout) :: wave !< instability wave
-        real(kind(0d0)) :: shift !< phase shift
-        real(kind(0d0)), dimension(0:nbp - 1) :: u_mean !<  mean density and velocity profiles
-        real(kind(0d0)) :: rho_mean, p_mean !< mean density and pressure
-        real(kind(0d0)), dimension(0:nbp - 1, 0:nbp - 1) :: d !< differential operator in y dir
-        real(kind(0d0)) :: gam, pi_inf, mach, c1, adv
-        real(kind(0d0)) :: xratio, uratio
+        real(wp), intent(in) :: alpha, beta !<  spatial wavenumbers
+        real(wp), dimension(mixlayer_nvar, 0:m, 0:n, 0:p), intent(inout) :: wave !< instability wave
+        real(wp) :: shift !< phase shift
+        real(wp), dimension(0:nbp - 1) :: u_mean !<  mean density and velocity profiles
+        real(wp) :: rho_mean, p_mean !< mean density and pressure
+        real(wp), dimension(0:nbp - 1, 0:nbp - 1) :: d !< differential operator in y dir
+        real(wp) :: gam, pi_inf, mach, c1, adv
+        real(wp) :: xratio, uratio
         integer :: i, j !<  generic loop iterators
 
         xratio = mixlayer_vel_coef
-        uratio = 1d0/patch_icpp(1)%vel(1)
+        uratio = 1._wp/patch_icpp(1)%vel(1)
 
         ! Set fluid flow properties
         if (bubbles) then
             adv = patch_icpp(1)%alpha(num_fluids)
         else
-            adv = 0d0
+            adv = 0._wp
         end if
-        gam = 1d0 + 1d0/fluid_pp(1)%gamma
-        pi_inf = fluid_pp(1)%pi_inf*(gam - 1d0)/gam*uratio**2
+        gam = 1._wp + 1._wp/fluid_pp(1)%gamma
+        pi_inf = fluid_pp(1)%pi_inf*(gam - 1._wp)/gam*uratio**2
         rho_mean = patch_icpp(1)%alpha_rho(1)
         p_mean = patch_icpp(1)%pres*uratio**2
-        c1 = sqrt((gam*(p_mean + pi_inf))/(rho_mean*(1d0 - adv)))
-        mach = 1d0/c1
+        c1 = sqrt((gam*(p_mean + pi_inf))/(rho_mean*(1._wp - adv)))
+        mach = 1._wp/c1
 
         ! Assign mean profiles
         do j = 0, n + 1
@@ -257,15 +257,15 @@ contains
 
         ! Compute differential operator in y-dir
         ! based on 2nd order central difference
-        d = 0d0
-        d(0, 0) = -1d0/((y_cb(0) - y_cb(-1))*xratio)
-        d(0, 1) = 1d0/((y_cb(0) - y_cb(-1))*xratio)
+        d = 0._wp
+        d(0, 0) = -1._wp/((y_cb(0) - y_cb(-1))*xratio)
+        d(0, 1) = 1._wp/((y_cb(0) - y_cb(-1))*xratio)
         do j = 1, n
-            d(j, j - 1) = -1d0/((y_cb(j) - y_cb(j - 2))*xratio)
-            d(j, j + 1) = 1d0/((y_cb(j) - y_cb(j - 2))*xratio)
+            d(j, j - 1) = -1._wp/((y_cb(j) - y_cb(j - 2))*xratio)
+            d(j, j + 1) = 1._wp/((y_cb(j) - y_cb(j - 2))*xratio)
         end do
-        d(n + 1, n) = -1d0/((y_cb(n) - y_cb(n - 1))*xratio)
-        d(n + 1, n + 1) = 1d0/((y_cb(n) - y_cb(n - 1))*xratio)
+        d(n + 1, n) = -1._wp/((y_cb(n) - y_cb(n - 1))*xratio)
+        d(n + 1, n + 1) = 1._wp/((y_cb(n) - y_cb(n - 1))*xratio)
 
         ! Compute
         call s_solve_linear_system(alpha, beta, u_mean, rho_mean, p_mean, d, gam, pi_inf, mach, wave, shift)
@@ -276,21 +276,21 @@ contains
         !!              generate instability waves for the given set of spatial
         !!              wave numbers and phase shift.
     subroutine s_solve_linear_system(alpha, beta, u_mean, rho_mean, p_mean, d, gam, pi_inf, mach, wave, shift)
-        real(kind(0d0)), intent(in) :: alpha, beta !<  spatial wavenumbers
-        real(kind(0d0)), dimension(0:nbp - 1), intent(in) :: u_mean !<  mean velocity profiles
-        real(kind(0d0)), intent(in) :: rho_mean, p_mean !< mean density and pressure
-        real(kind(0d0)), dimension(0:nbp - 1, 0:nbp - 1), intent(in) :: d !< differential operator in y dir
-        real(kind(0d0)), intent(in) :: gam, pi_inf, mach, shift
-        real(kind(0d0)), dimension(mixlayer_nvar, 0:m, 0:n, 0:p), intent(inout) :: wave
-
-        real(kind(0d0)), dimension(0:nbp - 1) :: drho_mean, du_mean !< y-derivatives of mean profiles
-        real(kind(0d0)), dimension(0:mixlayer_nvar*nbp - 1, 0:mixlayer_nvar*nbp - 1) :: ar, ai    !< matrices for eigenvalue problem
-        real(kind(0d0)), dimension(0:mixlayer_nvar*nbp - 1, 0:mixlayer_nvar*nbp - 1) :: br, bi, ci !< matrices for eigenvalue problem
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1) :: hr, hi    !< matrices for eigenvalue problem
-
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1) :: zr, zi !< eigenvectors
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1) :: wr, wi !< eigenvalues
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1) :: fv1, fv2, fv3 !< temporary memory
+        real(wp), intent(in) :: alpha, beta !<  spatial wavenumbers
+        real(wp), dimension(0:nbp - 1), intent(in) :: u_mean !<  mean velocity profiles
+        real(wp), intent(in) :: rho_mean, p_mean !< mean density and pressure
+        real(wp), dimension(0:nbp - 1, 0:nbp - 1), intent(in) :: d !< differential operator in y dir
+        real(wp), intent(in) :: gam, pi_inf, mach, shift
+        real(wp), dimension(mixlayer_nvar, 0:m, 0:n, 0:p), intent(inout) :: wave
+
+        real(wp), dimension(0:nbp - 1) :: drho_mean, du_mean !< y-derivatives of mean profiles
+        real(wp), dimension(0:mixlayer_nvar*nbp - 1, 0:mixlayer_nvar*nbp - 1) :: ar, ai    !< matrices for eigenvalue problem
+        real(wp), dimension(0:mixlayer_nvar*nbp - 1, 0:mixlayer_nvar*nbp - 1) :: br, bi, ci !< matrices for eigenvalue problem
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1) :: hr, hi    !< matrices for eigenvalue problem
+
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1) :: zr, zi !< eigenvectors
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1) :: wr, wi !< eigenvalues
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1) :: fv1, fv2, fv3 !< temporary memory
 
         integer :: ierr
         integer :: i, j, k, l !<  generic loop iterators
@@ -301,7 +301,7 @@ contains
             drho_mean(j) = 0
             du_mean(j) = 0
             do k = 0, nbp - 1
-                drho_mean(j) = 0d0
+                drho_mean(j) = 0._wp
                 du_mean(j) = du_mean(j) + d(j, k)*u_mean(k)
             end do
         end do
@@ -310,9 +310,9 @@ contains
         ! systems of equation (i.e. we are going to solve x for Ax = lambda x).
         ! Here, B includes components of A without differential operator, and
         ! C includes components of A with differential operator.
-        br = 0d0
-        bi = 0d0
-        ci = 0d0
+        br = 0._wp
+        bi = 0._wp
+        ci = 0._wp
         do j = 0, nbp - 1
             ii = mixlayer_var(1); jj = mixlayer_var(1); br((ii - 1)*nbp + j, (jj - 1)*nbp + j) = alpha*u_mean(j); 
             ii = mixlayer_var(1); jj = mixlayer_var(2); br((ii - 1)*nbp + j, (jj - 1)*nbp + j) = alpha*rho_mean; 
@@ -353,12 +353,12 @@ contains
     !> This subroutine applies non-reflecting subsonic buffer boundary condition
         !!              to the linear system of equations (i.e. matrix A).
     subroutine s_instability_nonreflecting_subsonic_buffer_bc(ar, ai, hr, hi, rho_mean, mach)
-        real(kind(0d0)), dimension(0:mixlayer_nvar*nbp - 1, 0:mixlayer_nvar*nbp - 1), intent(inout) :: ar, ai    !< matrices for eigenvalue problem
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1), intent(out) :: hr, hi    !< matrices for eigenvalue problem
-        real(kind(0d0)), intent(in) :: rho_mean !<  mean density profiles
-        real(kind(0d0)), intent(in) :: mach
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - 1, 0:mixlayer_nvar*n - 1) :: fr, fi    !< matrices for eigenvalue problem
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - 1) :: gr, gi    !< matrices for eigenvalue problem
+        real(wp), dimension(0:mixlayer_nvar*nbp - 1, 0:mixlayer_nvar*nbp - 1), intent(inout) :: ar, ai    !< matrices for eigenvalue problem
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1), intent(out) :: hr, hi    !< matrices for eigenvalue problem
+        real(wp), intent(in) :: rho_mean !<  mean density profiles
+        real(wp), intent(in) :: mach
+        real(wp), dimension(0:mixlayer_nvar*n - 1, 0:mixlayer_nvar*n - 1) :: fr, fi    !< matrices for eigenvalue problem
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - 1) :: gr, gi    !< matrices for eigenvalue problem
         integer :: i, j, k, l, ii, jj
 
         ! Condition 1: v = 0 at BC - no action required here
@@ -424,8 +424,8 @@ contains
         end do
 
         ! Remove unnecessary rows of the matrix A (rho, u, v, w, p at the boundaries)
-        fr = 0d0
-        fi = 0d0
+        fr = 0._wp
+        fi = 0._wp
         do ii = 1, mixlayer_nvar
             do jj = 1, mixlayer_nvar
                 do k = 0, n - 1
@@ -437,8 +437,8 @@ contains
             end do
         end do
 
-        gr = 0d0
-        gi = 0d0
+        gr = 0._wp
+        gi = 0._wp
         do ii = 1, mixlayer_nvar
             do j = 0, mixlayer_nvar*n - 1
                 if (ii <= mixlayer_var(2)) then
@@ -460,8 +460,8 @@ contains
             end do
         end do
 
-        hr = 0d0
-        hi = 0d0
+        hr = 0._wp
+        hi = 0._wp
         do i = 0, mixlayer_nvar*n - n_bc_skip - 1
             do jj = 1, mixlayer_nvar
                 if (jj <= mixlayer_var(2)) then
@@ -489,17 +489,17 @@ contains
         !!              eigenvalue and corresponding eigenvector among the
         !!              given set of eigenvalues and eigenvectors.
     subroutine s_generate_wave(wr, wi, zr, zi, rho_mean, mach, alpha, beta, wave, shift)
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1), intent(in) :: wr, wi !< eigenvalues
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1), intent(in) :: zr, zi !< eigenvectors
-        real(kind(0d0)), intent(in) :: rho_mean
-        real(kind(0d0)), dimension(mixlayer_nvar, 0:m, 0:n, 0:p), intent(inout) :: wave
-        real(kind(0d0)), intent(in) :: alpha, beta, mach, shift
-        real(kind(0d0)), dimension(0:mixlayer_nvar*n - n_bc_skip - 1) :: vr, vi, vnr, vni !< most unstable eigenvector
-        real(kind(0d0)), dimension(0:mixlayer_nvar*nbp - 1) :: xbr, xbi !< eigenvectors
-        real(kind(0d0)), dimension(0:mixlayer_nvar*(nbp - 1) - 1) :: xcr, xci !< eigenvectors
-        real(kind(0d0)) :: ang, norm
-        real(kind(0d0)) :: tr, ti, cr, ci !< temporary memory
-        real(kind(0d0)) :: xratio
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1), intent(in) :: wr, wi !< eigenvalues
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1, 0:mixlayer_nvar*n - n_bc_skip - 1), intent(in) :: zr, zi !< eigenvectors
+        real(wp), intent(in) :: rho_mean
+        real(wp), dimension(mixlayer_nvar, 0:m, 0:n, 0:p), intent(inout) :: wave
+        real(wp), intent(in) :: alpha, beta, mach, shift
+        real(wp), dimension(0:mixlayer_nvar*n - n_bc_skip - 1) :: vr, vi, vnr, vni !< most unstable eigenvector
+        real(wp), dimension(0:mixlayer_nvar*nbp - 1) :: xbr, xbi !< eigenvectors
+        real(wp), dimension(0:mixlayer_nvar*(nbp - 1) - 1) :: xcr, xci !< eigenvectors
+        real(wp) :: ang, norm
+        real(wp) :: tr, ti, cr, ci !< temporary memory
+        real(wp) :: xratio
         integer idx
         integer i, j, k
 
@@ -516,11 +516,11 @@ contains
         vi = zi(:, k)
 
         ! Normalize the eigenvector by its component with the largest modulus.
-        norm = 0d0
+        norm = 0._wp
         do i = 0, mixlayer_nvar*n - n_bc_skip - 1
-            if (dsqrt(vr(i)**2 + vi(i)**2) > norm) then
+            if (sqrt(vr(i)**2 + vi(i)**2) > norm) then
                 idx = i
-                norm = dsqrt(vr(i)**2 + vi(i)**2)
+                norm = sqrt(vr(i)**2 + vi(i)**2)
             end if
         end do
 
@@ -533,8 +533,8 @@ contains
         end do
 
         ! Reassign missing values at boundaries based on the boundary condition
-        xbr = 0d0
-        xbi = 0d0
+        xbr = 0._wp
+        xbi = 0._wp
         do i = 1, mixlayer_nvar
             if (i <= mixlayer_var(2)) then
                 do k = 0, n - 1
@@ -579,12 +579,12 @@ contains
         xbi(mixlayer_var(4)*nbp + nbp - 1) = xbi(mixlayer_var(4)*nbp + n) - xbi(mixlayer_var(2)*nbp + n)*rho_mean/mach
 
         ! Compute average to get cell-centered values
-        xcr = 0d0
-        xci = 0d0
+        xcr = 0._wp
+        xci = 0._wp
         do i = 1, mixlayer_nvar
             do k = 0, n
-                xcr((i - 1)*(nbp - 1) + k) = 5d-1*(xbr((i - 1)*nbp + k) + xbr((i - 1)*nbp + k + 1))
-                xci((i - 1)*(nbp - 1) + k) = 5d-1*(xbi((i - 1)*nbp + k) + xbi((i - 1)*nbp + k + 1))
+                xcr((i - 1)*(nbp - 1) + k) = 5e-1_wp*(xbr((i - 1)*nbp + k) + xbr((i - 1)*nbp + k + 1))
+                xci((i - 1)*(nbp - 1) + k) = 5e-1_wp*(xbi((i - 1)*nbp + k) + xbi((i - 1)*nbp + k + 1))
             end do
         end do
 
diff --git a/src/pre_process/m_start_up.fpp b/src/pre_process/m_start_up.fpp
index b1766418b..ba6c0b7fc 100644
--- a/src/pre_process/m_start_up.fpp
+++ b/src/pre_process/m_start_up.fpp
@@ -263,7 +263,7 @@ contains
         end if
 
         ! Computing cell-center locations
-        x_cc(0:m) = (x_cb(0:m) + x_cb(-1:(m - 1)))/2d0
+        x_cc(0:m) = (x_cb(0:m) + x_cb(-1:(m - 1)))/2._wp
 
         ! Computing minimum cell-width
         dx = minval(x_cb(0:m) - x_cb(-1:m - 1))
@@ -295,7 +295,7 @@ contains
             end if
 
             ! Computing cell-center locations
-            y_cc(0:n) = (y_cb(0:n) + y_cb(-1:(n - 1)))/2d0
+            y_cc(0:n) = (y_cb(0:n) + y_cb(-1:(n - 1)))/2._wp
 
             ! Computing minimum cell-width
             dy = minval(y_cb(0:n) - y_cb(-1:n - 1))
@@ -327,7 +327,7 @@ contains
                 end if
 
                 ! Computing cell-center locations
-                z_cc(0:p) = (z_cb(0:p) + z_cb(-1:(p - 1)))/2d0
+                z_cc(0:p) = (z_cb(0:p) + z_cb(-1:(p - 1)))/2._wp
 
                 ! Computing minimum cell-width
                 dz = minval(z_cb(0:p) - z_cb(-1:p - 1))
@@ -364,7 +364,7 @@ contains
 
         ! Cell-boundary Data Consistency Check in x-direction ==============
 
-        if (any(x_cb(0:m) - x_cb(-1:m - 1) <= 0d0)) then
+        if (any(x_cb(0:m) - x_cb(-1:m - 1) <= 0._wp)) then
             call s_mpi_abort('x_cb.dat in '//trim(t_step_dir)// &
                              ' contains non-positive cell-spacings. Exiting ...')
         end if
@@ -375,7 +375,7 @@ contains
 
         if (n > 0) then
 
-            if (any(y_cb(0:n) - y_cb(-1:n - 1) <= 0d0)) then
+            if (any(y_cb(0:n) - y_cb(-1:n - 1) <= 0._wp)) then
                 call s_mpi_abort('y_cb.dat in '//trim(t_step_dir)// &
                                  ' contains non-positive cell-spacings. '// &
                                  'Exiting ...')
@@ -387,7 +387,7 @@ contains
 
             if (p > 0) then
 
-                if (any(z_cb(0:p) - z_cb(-1:p - 1) <= 0d0)) then
+                if (any(z_cb(0:p) - z_cb(-1:p - 1) <= 0._wp)) then
                     call s_mpi_abort('z_cb.dat in '//trim(t_step_dir)// &
                                      ' contains non-positive cell-spacings'// &
                                      ' .Exiting ...')
@@ -420,7 +420,7 @@ contains
         ! Generic string used to store the address of a particular file
 
         character(LEN= &
-                  int(floor(log10(real(sys_size, kind(0d0))))) + 1) :: file_num !<
+                  int(floor(log10(real(sys_size, wp)))) + 1) :: file_num !<
             !! Used to store the variable position, in character form, of the
             !! currently manipulated conservative variable file
 
@@ -544,7 +544,7 @@ contains
 
 #ifdef MFC_MPI
 
-        real(kind(0d0)), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb
+        real(wp), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb
 
         integer :: ifile, ierr, data_size
         integer, dimension(MPI_STATUS_SIZE) :: status
@@ -563,7 +563,7 @@ contains
         if (file_exist) then
             data_size = m_glb + 2
             call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-            call MPI_FILE_READ_ALL(ifile, x_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+            call MPI_FILE_READ_ALL(ifile, x_cb_glb, data_size, mpi_p, status, ierr)
             call MPI_FILE_CLOSE(ifile, ierr)
         else
             call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting... ')
@@ -572,7 +572,7 @@ contains
         ! Assigning local cell boundary locations
         x_cb(-1:m) = x_cb_glb((start_idx(1) - 1):(start_idx(1) + m))
         ! Computing cell center locations
-        x_cc(0:m) = (x_cb(0:m) + x_cb(-1:(m - 1)))/2d0
+        x_cc(0:m) = (x_cb(0:m) + x_cb(-1:(m - 1)))/2._wp
         ! Computing minimum cell width
         dx = minval(x_cb(0:m) - x_cb(-1:(m - 1)))
         if (num_procs > 1) call s_mpi_reduce_min(dx)
@@ -588,7 +588,7 @@ contains
             if (file_exist) then
                 data_size = n_glb + 2
                 call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-                call MPI_FILE_READ_ALL(ifile, y_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                call MPI_FILE_READ_ALL(ifile, y_cb_glb, data_size, mpi_p, status, ierr)
                 call MPI_FILE_CLOSE(ifile, ierr)
             else
                 call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting... ')
@@ -597,7 +597,7 @@ contains
             ! Assigning local cell boundary locations
             y_cb(-1:n) = y_cb_glb((start_idx(2) - 1):(start_idx(2) + n))
             ! Computing cell center locations
-            y_cc(0:n) = (y_cb(0:n) + y_cb(-1:(n - 1)))/2d0
+            y_cc(0:n) = (y_cb(0:n) + y_cb(-1:(n - 1)))/2._wp
             ! Computing minimum cell width
             dy = minval(y_cb(0:n) - y_cb(-1:(n - 1)))
             if (num_procs > 1) call s_mpi_reduce_min(dy)
@@ -613,7 +613,7 @@ contains
                 if (file_exist) then
                     data_size = p_glb + 2
                     call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-                    call MPI_FILE_READ_ALL(ifile, z_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                    call MPI_FILE_READ_ALL(ifile, z_cb_glb, data_size, mpi_p, status, ierr)
                     call MPI_FILE_CLOSE(ifile, ierr)
                 else
                     call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting... ')
@@ -622,7 +622,7 @@ contains
                 ! Assigning local cell boundary locations
                 z_cb(-1:p) = z_cb_glb((start_idx(3) - 1):(start_idx(3) + p))
                 ! Computing cell center locations
-                z_cc(0:p) = (z_cb(0:p) + z_cb(-1:(p - 1)))/2d0
+                z_cc(0:p) = (z_cb(0:p) + z_cb(-1:(p - 1)))/2._wp
                 ! Computing minimum cell width
                 dz = minval(z_cb(0:p) - z_cb(-1:(p - 1)))
                 if (num_procs > 1) call s_mpi_reduce_min(dz)
@@ -695,8 +695,8 @@ contains
             m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
             n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
             p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-            WP_MOK = int(8d0, MPI_OFFSET_KIND)
-            MOK = int(1d0, MPI_OFFSET_KIND)
+            WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+            MOK = int(1._wp, MPI_OFFSET_KIND)
             str_MOK = int(name_len, MPI_OFFSET_KIND)
             NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -707,10 +707,10 @@ contains
                 ! Initial displacement to skip at beginning of file
                 disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                        'native', mpi_info_int, ierr)
                 call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                   MPI_DOUBLE_PRECISION, status, ierr)
+                                   mpi_p, status, ierr)
             end do
 
             if (qbmm .and. .not. polytropic) then
@@ -720,10 +720,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                       MPI_DOUBLE_PRECISION, status, ierr)
+                                       mpi_p, status, ierr)
                 end do
             end if
 
@@ -778,9 +778,9 @@ contains
         end if
         !Initialize pb based on surface tension for qbmm (polytropic)
         if (qbmm .and. polytropic .and. (.not. f_is_default(Web))) then
-            pb0 = pref + 2d0*fluid_pp(1)%ss/(R0*R0ref)
+            pb0 = pref + 2._wp*fluid_pp(1)%ss/(R0*R0ref)
             pb0 = pb0/pref
-            pref = 1d0
+            pref = 1._wp
         end if
         call s_initialize_data_output_module()
         call s_initialize_variables_conversion_module()
@@ -829,9 +829,9 @@ contains
 
     subroutine s_apply_initial_condition(start, finish, proc_time, time_avg, time_final, file_exists)
 
-        real(kind(0d0)), intent(inout) :: start, finish
-        real(kind(0d0)), dimension(:), intent(inout) :: proc_time
-        real(kind(0d0)), intent(inout) :: time_avg, time_final
+        real(wp), intent(inout) :: start, finish
+        real(wp), dimension(:), intent(inout) :: proc_time
+        real(wp), intent(inout) :: time_avg, time_final
         logical, intent(inout) :: file_exists
 
         ! Setting up the grid and the initial condition. If the grid is read in from
@@ -866,8 +866,8 @@ contains
 
     subroutine s_save_data(proc_time, time_avg, time_final, file_exists)
 
-        real(kind(0d0)), dimension(:), intent(inout) :: proc_time
-        real(kind(0d0)), intent(inout) :: time_avg, time_final
+        real(wp), dimension(:), intent(inout) :: proc_time
+        real(wp), intent(inout) :: time_avg, time_final
         logical, intent(inout) :: file_exists
 
         call s_mpi_barrier()
@@ -877,7 +877,7 @@ contains
         end if
 
         if (proc_rank == 0) then
-            time_final = 0d0
+            time_final = 0._wp
             if (num_procs == 1) then
                 time_final = time_avg
                 print *, "Elapsed Time", time_final
diff --git a/src/pre_process/p_main.f90 b/src/pre_process/p_main.f90
index 544c0311a..0bda585c0 100644
--- a/src/pre_process/p_main.f90
+++ b/src/pre_process/p_main.f90
@@ -18,8 +18,8 @@ program p_main
 
     integer :: i
     logical :: file_exists
-    real(kind(0d0)) :: start, finish, time_avg, time_final
-    real(kind(0d0)), allocatable, dimension(:) :: proc_time
+    real(wp) :: start, finish, time_avg, time_final
+    real(wp), allocatable, dimension(:) :: proc_time
 
     call random_seed()
 
diff --git a/src/simulation/include/inline_riemann.fpp b/src/simulation/include/inline_riemann.fpp
index 1af67bfb4..513c8c8c5 100644
--- a/src/simulation/include/inline_riemann.fpp
+++ b/src/simulation/include/inline_riemann.fpp
@@ -1,25 +1,26 @@
 #:def arithmetic_avg()
-    rho_avg = 5d-1*(rho_L + rho_R)
-    vel_avg_rms = 0d0
+    rho_avg = 5e-1_wp*(rho_L + rho_R)
+    vel_avg_rms = 0._wp
     !$acc loop seq
     do i = 1, num_dims
-        vel_avg_rms = vel_avg_rms + (5d-1*(vel_L(i) + vel_R(i)))**2d0
+        vel_avg_rms = vel_avg_rms + (5e-1_wp*(vel_L(i) + vel_R(i)))**2._wp
     end do
 
-    H_avg = 5d-1*(H_L + H_R)
-    gamma_avg = 5d-1*(gamma_L + gamma_R)
+    H_avg = 5e-1_wp*(H_L + H_R)
+    gamma_avg = 5e-1_wp*(gamma_L + gamma_R)
 
 #:enddef arithmetic_avg
 
 #:def roe_avg()
 
     rho_avg = sqrt(rho_L*rho_R)
-    vel_avg_rms = 0d0
+
+    vel_avg_rms = 0._wp
 
     !$acc loop seq
     do i = 1, num_dims
-        vel_avg_rms = vel_avg_rms + (sqrt(rho_L)*vel_L(i) + sqrt(rho_R)*vel_R(i))**2d0/ &
-                      (sqrt(rho_L) + sqrt(rho_R))**2d0
+        vel_avg_rms = vel_avg_rms + (sqrt(rho_L)*vel_L(i) + sqrt(rho_R)*vel_R(i))**2._wp/ &
+                      (sqrt(rho_L) + sqrt(rho_R))**2._wp
     end do
 
     H_avg = (sqrt(rho_L)*H_L + sqrt(rho_R)*H_R)/ &
@@ -28,11 +29,11 @@
     gamma_avg = (sqrt(rho_L)*gamma_L + sqrt(rho_R)*gamma_R)/ &
                 (sqrt(rho_L) + sqrt(rho_R))
 
-    vel_avg_rms = (sqrt(rho_L)*vel_L(1) + sqrt(rho_R)*vel_R(1))**2d0/ &
-                  (sqrt(rho_L) + sqrt(rho_R))**2d0
+    vel_avg_rms = (sqrt(rho_L)*vel_L(1) + sqrt(rho_R)*vel_R(1))**2._wp/ &
+                  (sqrt(rho_L) + sqrt(rho_R))**2._wp
 
     if (chemistry) then
-        eps = 0.001d0
+        eps = 0.001_wp
         call get_species_enthalpies_rt(T_L, h_iL)
         call get_species_enthalpies_rt(T_R, h_iR)
 
@@ -47,8 +48,8 @@
 
         if (abs(T_L - T_R) < eps) then
             ! Case when T_L and T_R are very close
-            Cp_avg = sum(Yi_avg(:)*(0.5d0*Cp_iL(i) + 0.5d0*Cp_iR(:))*gas_constant/mol_weights(:))
-            Cv_avg = sum(Yi_avg(:)*((0.5d0*Cp_iL(i) + 0.5d0*Cp_iR(:))*gas_constant/mol_weights(:) - gas_constant/mol_weights(:)))
+            Cp_avg = sum(Yi_avg(:)*(0.5_wp*Cp_iL(i) + 0.5_wp*Cp_iR(:))*gas_constant/mol_weights(:))
+            Cv_avg = sum(Yi_avg(:)*((0.5_wp*Cp_iL(i) + 0.5_wp*Cp_iR(:))*gas_constant/mol_weights(:) - gas_constant/mol_weights(:)))
         else
             ! Normal calculation when T_L and T_R are sufficiently different
             Cp_avg = sum(Yi_avg(:)*(h_iR(:) - h_iL(:))/(T_R - T_L))
@@ -57,7 +58,7 @@
 
         gamma_avg = Cp_avg/Cv_avg
 
-        Phi_avg(:) = (gamma_avg - 1.d0)*(vel_avg_rms/2.0d0 - h_avg_2(:)) + gamma_avg*gas_constant/mol_weights(:)*T_avg
+        Phi_avg(:) = (gamma_avg - 1._wp)*(vel_avg_rms/2.0_wp - h_avg_2(:)) + gamma_avg*gas_constant/mol_weights(:)*T_avg
         c_sum_Yi_Phi = sum(Yi_avg(:)*Phi_avg(:))
     end if
 
@@ -77,17 +78,17 @@
 
 #:def compute_low_Mach_correction()
 
-    zcoef = min(1d0, max(vel_L_rms**5d-1/c_L, vel_R_rms**5d-1/c_R))
-    pcorr = 0d0
+    zcoef = min(1._wp, max(vel_L_rms**5e-1_wp/c_L, vel_R_rms**5e-1_wp/c_R))
+    pcorr = 0._wp
 
     if (low_Mach == 1) then
         pcorr = rho_L*rho_R* &
                 (s_L - vel_L(dir_idx(1)))*(s_R - vel_R(dir_idx(1)))*(vel_R(dir_idx(1)) - vel_L(dir_idx(1)))/ &
                 (rho_R*(s_R - vel_R(dir_idx(1))) - rho_L*(s_L - vel_L(dir_idx(1))))* &
-                (zcoef - 1d0)
+                (zcoef - 1._wp)
     else if (low_Mach == 2) then
-        vel_L_tmp = 5d-1*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + zcoef*(vel_L(dir_idx(1)) - vel_R(dir_idx(1))))
-        vel_R_tmp = 5d-1*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + zcoef*(vel_R(dir_idx(1)) - vel_L(dir_idx(1))))
+        vel_L_tmp = 5e-1_wp*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + zcoef*(vel_L(dir_idx(1)) - vel_R(dir_idx(1))))
+        vel_R_tmp = 5e-1_wp*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + zcoef*(vel_R(dir_idx(1)) - vel_L(dir_idx(1))))
         vel_L(dir_idx(1)) = vel_L_tmp
         vel_R(dir_idx(1)) = vel_R_tmp
     end if
diff --git a/src/simulation/m_acoustic_src.fpp b/src/simulation/m_acoustic_src.fpp
index 7879390bf..2af0dd672 100644
--- a/src/simulation/m_acoustic_src.fpp
+++ b/src/simulation/m_acoustic_src.fpp
@@ -29,19 +29,19 @@ module m_acoustic_src
     logical, allocatable, dimension(:) :: dipole
     !$acc declare create(dipole)
 
-    real(kind(0d0)), allocatable, target, dimension(:, :) :: loc_acoustic
+    real(wp), allocatable, target, dimension(:, :) :: loc_acoustic
     !$acc declare create(loc_acoustic)
 
-    real(kind(0d0)), allocatable, dimension(:) :: mag, length, height, wavelength, frequency, gauss_sigma_dist, gauss_sigma_time, npulse, dir, delay
+    real(wp), allocatable, dimension(:) :: mag, length, height, wavelength, frequency, gauss_sigma_dist, gauss_sigma_time, npulse, dir, delay
     !$acc declare create(mag, length, height, wavelength, frequency, gauss_sigma_dist, gauss_sigma_time, npulse, dir, delay)
 
-    real(kind(0d0)), allocatable, dimension(:) :: foc_length, aperture
+    real(wp), allocatable, dimension(:) :: foc_length, aperture
     !$acc declare create(foc_length, aperture)
 
-    real(kind(0d0)), allocatable, dimension(:) :: element_spacing_angle, element_polygon_ratio, rotate_angle
+    real(wp), allocatable, dimension(:) :: element_spacing_angle, element_polygon_ratio, rotate_angle
     !$acc declare create(element_spacing_angle, element_polygon_ratio, rotate_angle)
 
-    real(kind(0d0)), allocatable, dimension(:) :: bb_bandwidth, bb_lowest_freq
+    real(wp), allocatable, dimension(:) :: bb_bandwidth, bb_lowest_freq
     !$acc declare create(bb_bandwidth, bb_lowest_freq)
 
     integer, allocatable, dimension(:) :: num_elements, element_on, bb_num_freq
@@ -49,8 +49,8 @@ module m_acoustic_src
 
     !> @name Acoustic source terms
     !> @{
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: mass_src, e_src
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: mom_src
+    real(wp), allocatable, dimension(:, :, :) :: mass_src, e_src
+    real(wp), allocatable, dimension(:, :, :, :) :: mom_src
     !> @}
     !$acc declare create(mass_src, e_src, mom_src)
 
@@ -99,12 +99,12 @@ contains
                 element_on(i) = acoustic(i)%element_on
             end if
             if (f_is_default(acoustic(i)%rotate_angle)) then
-                rotate_angle(i) = 0d0
+                rotate_angle(i) = 0._wp
             else
                 rotate_angle(i) = acoustic(i)%rotate_angle
             end if
             if (f_is_default(acoustic(i)%delay)) then ! m_checker guarantees acoustic(i)%delay is set for pulse = 2 (Gaussian)
-                delay(i) = 0d0 ! Defaults to zero for sine and square waves
+                delay(i) = 0._wp ! Defaults to zero for sine and square waves
             else
                 delay(i) = acoustic(i)%delay
             end if
@@ -138,17 +138,17 @@ contains
 
         integer, intent(in) :: t_step
 
-        real(kind(0d0)) :: myalpha(num_fluids), myalpha_rho(num_fluids)
-        real(kind(0d0)) :: myRho, B_tait
-        real(kind(0d0)) :: sim_time, c, small_gamma
-        real(kind(0d0)) :: frequency_local, gauss_sigma_time_local
-        real(kind(0d0)) :: mass_src_diff, mom_src_diff
-        real(kind(0d0)) :: source_temporal
-        real(kind(0d0)) :: period_BB !< period of each sine wave in broadband source
-        real(kind(0d0)) :: sl_BB !< spectral level at each frequency
-        real(kind(0d0)) :: ffre_BB !< source term corresponding to each frequency
-        real(kind(0d0)) :: sum_BB !< total source term for the broadband wave
-        real(kind(0d0)), allocatable, dimension(:) :: phi_rn !< random phase shift for each frequency
+        real(wp) :: myalpha(num_fluids), myalpha_rho(num_fluids)
+        real(wp) :: myRho, B_tait
+        real(wp) :: sim_time, c, small_gamma
+        real(wp) :: frequency_local, gauss_sigma_time_local
+        real(wp) :: mass_src_diff, mom_src_diff
+        real(wp) :: source_temporal
+        real(wp) :: period_BB !< period of each sine wave in broadband source
+        real(wp) :: sl_BB !< spectral level at each frequency
+        real(wp) :: ffre_BB !< source term corresponding to each frequency
+        real(wp) :: sum_BB !< total source term for the broadband wave
+        real(wp), allocatable, dimension(:) :: phi_rn !< random phase shift for each frequency
 
         integer :: i, j, k, l, q !< generic loop variables
         integer :: ai !< acoustic source index
@@ -164,11 +164,11 @@ contains
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    mass_src(j, k, l) = 0d0
-                    mom_src(1, j, k, l) = 0d0
-                    e_src(j, k, l) = 0d0
-                    if (n > 0) mom_src(2, j, k, l) = 0d0
-                    if (p > 0) mom_src(3, j, k, l) = 0d0
+                    mass_src(j, k, l) = 0._wp
+                    mom_src(1, j, k, l) = 0._wp
+                    e_src(j, k, l) = 0._wp
+                    if (n > 0) mom_src(2, j, k, l) = 0._wp
+                    if (p > 0) mom_src(3, j, k, l) = 0._wp
                 end do
             end do
         end do
@@ -185,10 +185,10 @@ contains
             num_points = source_spatials_num_points(ai) ! Use scalar to force firstprivate to prevent GPU bug
 
             ! Calculate the broadband source
-            period_BB = 0d0
-            sl_BB = 0d0
-            ffre_BB = 0d0
-            sum_BB = 0d0
+            period_BB = 0._wp
+            sl_BB = 0._wp
+            ffre_BB = 0._wp
+            sum_BB = 0._wp
 
             ! Allocate buffers for random phase shift
             allocate (phi_rn(1:bb_num_freq(ai)))
@@ -202,11 +202,11 @@ contains
             !$acc loop reduction(+:sum_BB)
             do k = 1, bb_num_freq(ai)
                 ! Acoustic period of the wave at each discrete frequency
-                period_BB = 1d0/(bb_lowest_freq(ai) + k*bb_bandwidth(ai))
+                period_BB = 1._wp/(bb_lowest_freq(ai) + k*bb_bandwidth(ai))
                 ! Spectral level at each frequency
                 sl_BB = broadband_spectral_level_constant*mag(ai) + k*mag(ai)/broadband_spectral_level_growth_rate
                 ! Source term corresponding to each frequencies
-                ffre_BB = dsqrt((2d0*sl_BB*bb_bandwidth(ai)))*cos((sim_time)*2d0*pi/period_BB + 2d0*pi*phi_rn(k))
+                ffre_BB = sqrt((2._wp*sl_BB*bb_bandwidth(ai)))*cos((sim_time)*2._wp*pi/period_BB + 2._wp*pi*phi_rn(k))
                 ! Sum up the source term of each frequency to obtain the total source term for broadband wave
                 sum_BB = sum_BB + ffre_BB
             end do
@@ -220,9 +220,9 @@ contains
                 l = source_spatials(ai)%coord(3, i)
 
                 ! Compute speed of sound
-                myRho = 0d0
-                B_tait = 0d0
-                small_gamma = 0d0
+                myRho = 0._wp
+                B_tait = 0._wp
+                small_gamma = 0._wp
 
                 !$acc loop
                 do q = 1, num_fluids
@@ -254,8 +254,8 @@ contains
                     end do
                 end if
 
-                small_gamma = 1d0/small_gamma + 1d0
-                c = dsqrt(small_gamma*(q_prim_vf(E_idx)%sf(j, k, l) + ((small_gamma - 1d0)/small_gamma)*B_tait)/myRho)
+                small_gamma = 1._wp/small_gamma + 1._wp
+                c = sqrt(small_gamma*(q_prim_vf(E_idx)%sf(j, k, l) + ((small_gamma - 1._wp)/small_gamma)*B_tait)/myRho)
 
                 ! Wavelength to frequency conversion
                 if (pulse(ai) == 1 .or. pulse(ai) == 3) frequency_local = f_frequency_local(freq_conv_flag, ai, c)
@@ -266,13 +266,13 @@ contains
                 mom_src_diff = source_temporal*source_spatials(ai)%val(i)
 
                 if (dipole(ai)) then ! Double amplitude & No momentum source term (only works for Planar)
-                    mass_src(j, k, l) = mass_src(j, k, l) + 2d0*mom_src_diff/c
-                    if (model_eqns /= 4) E_src(j, k, l) = E_src(j, k, l) + 2d0*mom_src_diff*c/(small_gamma - 1d0)
+                    mass_src(j, k, l) = mass_src(j, k, l) + 2._wp*mom_src_diff/c
+                    if (model_eqns /= 4) E_src(j, k, l) = E_src(j, k, l) + 2._wp*mom_src_diff*c/(small_gamma - 1._wp)
                     cycle
                 end if
 
                 if (n == 0) then ! 1D
-                    mom_src(1, j, k, l) = mom_src(1, j, k, l) + mom_src_diff*sign(1d0, dir(ai)) ! Left or right-going wave
+                    mom_src(1, j, k, l) = mom_src(1, j, k, l) + mom_src_diff*sign(1._wp, dir(ai)) ! Left or right-going wave
 
                 elseif (p == 0) then ! 2D
                     if (support(ai) < 5) then ! Planar
@@ -306,7 +306,7 @@ contains
 
                 ! Update energy source term
                 if (model_eqns /= 4) then
-                    E_src(j, k, l) = E_src(j, k, l) + mass_src_diff*c**2d0/(small_gamma - 1d0)
+                    E_src(j, k, l) = E_src(j, k, l) + mass_src_diff*c**2._wp/(small_gamma - 1._wp)
                 end if
 
             end do
@@ -342,55 +342,55 @@ contains
     subroutine s_source_temporal(sim_time, c, ai, term_index, frequency_local, gauss_sigma_time_local, source, sum_BB)
         !$acc routine seq
         integer, intent(in) :: ai, term_index
-        real(kind(0d0)), intent(in) :: sim_time, c, sum_BB
-        real(kind(0d0)), intent(in) :: frequency_local, gauss_sigma_time_local
-        real(kind(0d0)), intent(out) :: source
+        real(wp), intent(in) :: sim_time, c, sum_BB
+        real(wp), intent(in) :: frequency_local, gauss_sigma_time_local
+        real(wp), intent(out) :: source
 
-        real(kind(0d0)) :: omega ! angular frequency
-        real(kind(0d0)) :: sine_wave ! sine function for square wave
-        real(kind(0d0)) :: foc_length_factor ! Scale amplitude with radius for spherical support
+        real(wp) :: omega ! angular frequency
+        real(wp) :: sine_wave ! sine function for square wave
+        real(wp) :: foc_length_factor ! Scale amplitude with radius for spherical support
         ! i.e. Spherical support -> 1/r scaling; Cylindrical support -> 1/sqrt(r) [empirical correction: ^-0.5 -> ^-0.85]
         integer, parameter :: mass_label = 1
 
         if (n == 0) then
-            foc_length_factor = 1d0
+            foc_length_factor = 1._wp
         elseif (p == 0 .and. (.not. cyl_coord)) then ! 2D axisymmetric case is physically 3D
-            foc_length_factor = foc_length(ai)**(-0.85d0); ! Empirical correction
+            foc_length_factor = foc_length(ai)**(-0.85_wp); ! Empirical correction
         else
             foc_length_factor = 1/foc_length(ai); 
         end if
 
-        source = 0d0
+        source = 0._wp
 
         if (pulse(ai) == 1) then ! Sine wave
             if ((sim_time - delay(ai))*frequency_local > npulse(ai)) return
 
-            omega = 2d0*pi*frequency_local
+            omega = 2._wp*pi*frequency_local
             source = mag(ai)*sin((sim_time - delay(ai))*omega)
 
             if (term_index == mass_label) then
-                source = source/c + foc_length_factor*mag(ai)*(cos((sim_time - delay(ai))*omega) - 1d0)/omega
+                source = source/c + foc_length_factor*mag(ai)*(cos((sim_time - delay(ai))*omega) - 1._wp)/omega
             end if
 
         elseif (pulse(ai) == 2) then ! Gaussian pulse
-            source = mag(ai)*dexp(-0.5d0*((sim_time - delay(ai))**2d0)/(gauss_sigma_time_local**2d0))
+            source = mag(ai)*exp(-0.5_wp*((sim_time - delay(ai))**2._wp)/(gauss_sigma_time_local**2._wp))
 
             if (term_index == mass_label) then
                 source = source/c - &
-                         foc_length_factor*mag(ai)*dsqrt(pi/2)*gauss_sigma_time_local* &
-                         (erf((sim_time - delay(ai))/(dsqrt(2d0)*gauss_sigma_time_local)) + 1)
+                         foc_length_factor*mag(ai)*sqrt(pi/2)*gauss_sigma_time_local* &
+                         (erf((sim_time - delay(ai))/(sqrt(2._wp)*gauss_sigma_time_local)) + 1)
             end if
 
         elseif (pulse(ai) == 3) then ! Square wave
             if ((sim_time - delay(ai))*frequency_local > npulse(ai)) return
 
-            omega = 2d0*pi*frequency_local
+            omega = 2._wp*pi*frequency_local
             sine_wave = sin((sim_time - delay(ai))*omega)
-            source = mag(ai)*sign(1d0, sine_wave)
+            source = mag(ai)*sign(1._wp, sine_wave)
 
             ! Prevent max-norm differences due to compilers to pass CI
-            if (abs(sine_wave) < 1d-2) then
-                source = mag(ai)*sine_wave*1d2
+            if (abs(sine_wave) < 1e-2_wp) then
+                source = mag(ai)*sine_wave*1e2_wp
             end if
 
         elseif (pulse(ai) == 4) then ! Broadband wave
@@ -403,8 +403,8 @@ contains
         integer :: j, k, l, ai
         integer :: count
         integer :: dim
-        real(kind(0d0)) :: source_spatial, angle, xyz_to_r_ratios(3)
-        real(kind(0d0)), parameter :: threshold = 1d-10
+        real(wp) :: source_spatial, angle, xyz_to_r_ratios(3)
+        real(wp), parameter :: threshold = 1e-10_wp
 
         if (n == 0) then
             dim = 1
@@ -500,10 +500,10 @@ contains
     !! @param xyz_to_r_ratios Ratios of the [xyz]-component of the source term to the magnitude (for 3D)
     subroutine s_source_spatial(j, k, l, loc, ai, source, angle, xyz_to_r_ratios)
         integer, intent(in) :: j, k, l, ai
-        real(kind(0d0)), dimension(3), intent(in) :: loc
-        real(kind(0d0)), intent(out) :: source, angle, xyz_to_r_ratios(3)
+        real(wp), dimension(3), intent(in) :: loc
+        real(wp), intent(out) :: source, angle, xyz_to_r_ratios(3)
 
-        real(kind(0d0)) :: sig, r(3)
+        real(wp) :: sig, r(3)
 
         ! Calculate sig spatial support width
         if (n == 0) then
@@ -536,22 +536,22 @@ contains
     !! @param source Source term amplitude
     subroutine s_source_spatial_planar(ai, sig, r, source)
         integer, intent(in) :: ai
-        real(kind(0d0)), intent(in) :: sig, r(3)
-        real(kind(0d0)), intent(out) :: source
+        real(wp), intent(in) :: sig, r(3)
+        real(wp), intent(out) :: source
 
-        real(kind(0d0)) :: dist
+        real(wp) :: dist
 
-        source = 0d0
+        source = 0._wp
 
         if (support(ai) == 1) then ! 1D
-            source = 1d0/(dsqrt(2d0*pi)*sig/2d0)*dexp(-0.5d0*(r(1)/(sig/2d0))**2d0)
+            source = 1._wp/(sqrt(2._wp*pi)*sig/2._wp)*exp(-0.5_wp*(r(1)/(sig/2._wp))**2._wp)
 
         elseif (support(ai) == 2 .or. support(ai) == 3) then ! 2D or 3D
             ! If we let unit vector e = (cos(dir), sin(dir)),
             dist = r(1)*cos(dir(ai)) + r(2)*sin(dir(ai)) ! dot(r,e)
-            if ((r(1) - dist*cos(dir(ai)))**2d0 + (r(2) - dist*sin(dir(ai)))**2d0 < 0.25d0*length(ai)**2d0) then ! |r - dist*e| < length/2
-                if (support(ai) /= 3 .or. abs(r(3)) < 0.25d0*height(ai)) then ! additional height constraint for 3D
-                    source = 1d0/(dsqrt(2d0*pi)*sig/2d0)*dexp(-0.5d0*(dist/(sig/2d0))**2d0)
+            if ((r(1) - dist*cos(dir(ai)))**2._wp + (r(2) - dist*sin(dir(ai)))**2._wp < 0.25_wp*length(ai)**2._wp) then ! |r - dist*e| < length/2
+                if (support(ai) /= 3 .or. abs(r(3)) < 0.25_wp*height(ai)) then ! additional height constraint for 3D
+                    source = 1._wp/(sqrt(2._wp*pi)*sig/2._wp)*exp(-0.5_wp*(dist/(sig/2._wp))**2._wp)
                 end if
             end if
         end if
@@ -566,34 +566,34 @@ contains
     !! @param xyz_to_r_ratios Ratios of the [xyz]-component of the source term to the magnitude (for 3D)
     subroutine s_source_spatial_transducer(ai, sig, r, source, angle, xyz_to_r_ratios)
         integer, intent(in) :: ai
-        real(kind(0d0)), intent(in) :: sig, r(3)
-        real(kind(0d0)), intent(out) :: source, angle, xyz_to_r_ratios(3)
+        real(wp), intent(in) :: sig, r(3)
+        real(wp), intent(out) :: source, angle, xyz_to_r_ratios(3)
 
-        real(kind(0d0)) :: current_angle, angle_half_aperture, dist, norm
+        real(wp) :: current_angle, angle_half_aperture, dist, norm
 
-        source = 0d0 ! If not affected by transducer
-        angle = 0d0
-        xyz_to_r_ratios = 0d0
+        source = 0._wp ! If not affected by transducer
+        angle = 0._wp
+        xyz_to_r_ratios = 0._wp
 
         if (support(ai) == 5 .or. support(ai) == 6) then ! 2D or 2D axisymmetric
             current_angle = -atan(r(2)/(foc_length(ai) - r(1)))
-            angle_half_aperture = asin((aperture(ai)/2d0)/(foc_length(ai)))
+            angle_half_aperture = asin((aperture(ai)/2._wp)/(foc_length(ai)))
 
             if (abs(current_angle) < angle_half_aperture .and. r(1) < foc_length(ai)) then
-                dist = foc_length(ai) - dsqrt(r(2)**2d0 + (foc_length(ai) - r(1))**2d0)
-                source = 1d0/(dsqrt(2d0*pi)*sig/2d0)*dexp(-0.5d0*(dist/(sig/2d0))**2d0)
+                dist = foc_length(ai) - sqrt(r(2)**2._wp + (foc_length(ai) - r(1))**2._wp)
+                source = 1._wp/(sqrt(2._wp*pi)*sig/2._wp)*exp(-0.5_wp*(dist/(sig/2._wp))**2._wp)
                 angle = -atan(r(2)/(foc_length(ai) - r(1)))
             end if
 
         elseif (support(ai) == 7) then ! 3D
-            current_angle = -atan(dsqrt(r(2)**2 + r(3)**2)/(foc_length(ai) - r(1)))
-            angle_half_aperture = asin((aperture(ai)/2d0)/(foc_length(ai)))
+            current_angle = -atan(sqrt(r(2)**2 + r(3)**2)/(foc_length(ai) - r(1)))
+            angle_half_aperture = asin((aperture(ai)/2._wp)/(foc_length(ai)))
 
             if (abs(current_angle) < angle_half_aperture .and. r(1) < foc_length(ai)) then
-                dist = foc_length(ai) - dsqrt(r(2)**2d0 + r(3)**2d0 + (foc_length(ai) - r(1))**2d0)
-                source = 1d0/(dsqrt(2d0*pi)*sig/2d0)*dexp(-0.5d0*(dist/(sig/2d0))**2d0)
+                dist = foc_length(ai) - sqrt(r(2)**2._wp + r(3)**2._wp + (foc_length(ai) - r(1))**2._wp)
+                source = 1._wp/(sqrt(2._wp*pi)*sig/2._wp)*exp(-0.5_wp*(dist/(sig/2._wp))**2._wp)
 
-                norm = dsqrt(r(2)**2d0 + r(3)**2d0 + (foc_length(ai) - r(1))**2d0)
+                norm = sqrt(r(2)**2._wp + r(3)**2._wp + (foc_length(ai) - r(1))**2._wp)
                 xyz_to_r_ratios(1) = -(r(1) - foc_length(ai))/norm
                 xyz_to_r_ratios(2) = -r(2)/norm
                 xyz_to_r_ratios(3) = -r(3)/norm
@@ -611,14 +611,14 @@ contains
     !! @param xyz_to_r_ratios Ratios of the [xyz]-component of the source term to the magnitude (for 3D)
     subroutine s_source_spatial_transducer_array(ai, sig, r, source, angle, xyz_to_r_ratios)
         integer, intent(in) :: ai
-        real(kind(0d0)), intent(in) :: sig, r(3)
-        real(kind(0d0)), intent(out) :: source, angle, xyz_to_r_ratios(3)
+        real(wp), intent(in) :: sig, r(3)
+        real(wp), intent(out) :: source, angle, xyz_to_r_ratios(3)
 
         integer :: elem, elem_min, elem_max
-        real(kind(0d0)) :: current_angle, angle_half_aperture, angle_per_elem, dist
-        real(kind(0d0)) :: angle_min, angle_max, norm
-        real(kind(0d0)) :: poly_side_length, aperture_element_3D, angle_elem
-        real(kind(0d0)) :: x2, y2, z2, x3, y3, z3, C, f, half_apert, dist_interp_to_elem_center
+        real(wp) :: current_angle, angle_half_aperture, angle_per_elem, dist
+        real(wp) :: angle_min, angle_max, norm
+        real(wp) :: poly_side_length, aperture_element_3D, angle_elem
+        real(wp) :: x2, y2, z2, x3, y3, z3, C, f, half_apert, dist_interp_to_elem_center
 
         if (element_on(ai) == 0) then ! Full transducer
             elem_min = 1
@@ -628,22 +628,22 @@ contains
             elem_max = element_on(ai)
         end if
 
-        source = 0d0 ! If not affected by any transducer element
-        angle = 0d0
-        xyz_to_r_ratios = 0d0
+        source = 0._wp ! If not affected by any transducer element
+        angle = 0._wp
+        xyz_to_r_ratios = 0._wp
 
         if (support(ai) == 9 .or. support(ai) == 10) then ! 2D or 2D axisymmetric
             current_angle = -atan(r(2)/(foc_length(ai) - r(1)))
-            angle_half_aperture = asin((aperture(ai)/2d0)/(foc_length(ai)))
-            angle_per_elem = (2d0*angle_half_aperture - (num_elements(ai) - 1d0)*element_spacing_angle(ai))/num_elements(ai)
-            dist = foc_length(ai) - dsqrt(r(2)**2d0 + (foc_length(ai) - r(1))**2d0)
+            angle_half_aperture = asin((aperture(ai)/2._wp)/(foc_length(ai)))
+            angle_per_elem = (2._wp*angle_half_aperture - (num_elements(ai) - 1._wp)*element_spacing_angle(ai))/num_elements(ai)
+            dist = foc_length(ai) - sqrt(r(2)**2._wp + (foc_length(ai) - r(1))**2._wp)
 
             do elem = elem_min, elem_max
-                angle_max = angle_half_aperture - (element_spacing_angle(ai) + angle_per_elem)*(elem - 1d0)
+                angle_max = angle_half_aperture - (element_spacing_angle(ai) + angle_per_elem)*(elem - 1._wp)
                 angle_min = angle_max - angle_per_elem
 
                 if (current_angle > angle_min .and. current_angle < angle_max .and. r(1) < foc_length(ai)) then
-                    source = dexp(-0.5d0*(dist/(sig/2d0))**2d0)/(dsqrt(2d0*pi)*sig/2d0)
+                    source = exp(-0.5_wp*(dist/(sig/2._wp))**2._wp)/(sqrt(2._wp*pi)*sig/2._wp)
                     angle = current_angle
                     exit ! Assume elements don't overlap
                 end if
@@ -653,29 +653,29 @@ contains
             poly_side_length = aperture(ai)*sin(pi/num_elements(ai))
             aperture_element_3D = poly_side_length*element_polygon_ratio(ai)
             f = foc_length(ai)
-            half_apert = aperture(ai)/2d0
+            half_apert = aperture(ai)/2._wp
 
             do elem = elem_min, elem_max
-                angle_elem = 2d0*pi*real(elem, kind(0d0))/real(num_elements(ai), kind(0d0)) + rotate_angle(ai)
+                angle_elem = 2._wp*pi*real(elem, wp)/real(num_elements(ai), wp) + rotate_angle(ai)
 
                 ! Point 2 is the elem center
-                x2 = f - dsqrt(f**2 - half_apert**2)
+                x2 = f - sqrt(f**2 - half_apert**2)
                 y2 = half_apert*cos(angle_elem)
                 z2 = half_apert*sin(angle_elem)
 
                 ! Construct a plane normal to the line from the focal point to the elem center,
                 ! Point 3 is the intercept of the plane and the line from the focal point to the current location
-                C = f**2d0/((r(1) - f)*(x2 - f) + r(2)*y2 + r(3)*z2) ! Constant for intermediate step
+                C = f**2._wp/((r(1) - f)*(x2 - f) + r(2)*y2 + r(3)*z2) ! Constant for intermediate step
                 x3 = C*(r(1) - f) + f
                 y3 = C*r(2)
                 z3 = C*r(3)
 
-                dist_interp_to_elem_center = dsqrt((x2 - x3)**2d0 + (y2 - y3)**2d0 + (z2 - z3)**2d0)
-                if ((dist_interp_to_elem_center < aperture_element_3D/2d0) .and. (r(1) < f)) then
-                    dist = dsqrt((x3 - r(1))**2d0 + (y3 - r(2))**2d0 + (z3 - r(3))**2d0)
-                    source = dexp(-0.5d0*(dist/(sig/2d0))**2d0)/(dsqrt(2d0*pi)*sig/2d0)
+                dist_interp_to_elem_center = sqrt((x2 - x3)**2._wp + (y2 - y3)**2._wp + (z2 - z3)**2._wp)
+                if ((dist_interp_to_elem_center < aperture_element_3D/2._wp) .and. (r(1) < f)) then
+                    dist = sqrt((x3 - r(1))**2._wp + (y3 - r(2))**2._wp + (z3 - r(3))**2._wp)
+                    source = exp(-0.5_wp*(dist/(sig/2._wp))**2._wp)/(sqrt(2._wp*pi)*sig/2._wp)
 
-                    norm = dsqrt(r(2)**2d0 + r(3)**2d0 + (f - r(1))**2d0)
+                    norm = sqrt(r(2)**2._wp + r(3)**2._wp + (f - r(1))**2._wp)
                     xyz_to_r_ratios(1) = -(r(1) - f)/norm
                     xyz_to_r_ratios(2) = -r(2)/norm
                     xyz_to_r_ratios(3) = -r(3)/norm
@@ -695,8 +695,8 @@ contains
         !$acc routine seq
         logical, intent(in) :: freq_conv_flag
         integer, intent(in) :: ai
-        real(kind(0d0)), intent(in) :: c
-        real(kind(0d0)) :: f_frequency_local
+        real(wp), intent(in) :: c
+        real(wp) :: f_frequency_local
 
         if (freq_conv_flag) then
             f_frequency_local = c/wavelength(ai)
@@ -714,8 +714,8 @@ contains
         !$acc routine seq
         logical, intent(in) :: gauss_conv_flag
         integer, intent(in) :: ai
-        real(kind(0d0)), intent(in) :: c
-        real(kind(0d0)) :: f_gauss_sigma_time_local
+        real(wp), intent(in) :: c
+        real(wp) :: f_gauss_sigma_time_local
 
         if (gauss_conv_flag) then
             f_gauss_sigma_time_local = gauss_sigma_dist(ai)/c
diff --git a/src/simulation/m_body_forces.fpp b/src/simulation/m_body_forces.fpp
index 7368fc046..9892e48f4 100644
--- a/src/simulation/m_body_forces.fpp
+++ b/src/simulation/m_body_forces.fpp
@@ -24,7 +24,7 @@ module m_body_forces
               s_initialize_body_forces_module, &
               s_finalize_body_forces_module
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: rhoM
+    real(wp), allocatable, dimension(:, :, :) :: rhoM
     !$acc declare create(rhoM)
 
 contains
@@ -58,7 +58,7 @@ contains
     !> This subroutine computes the acceleration at time t
     subroutine s_compute_acceleration(t)
 
-        real(kind(0d0)), intent(in) :: t
+        real(wp), intent(in) :: t
 
         if (m > 0) then
             accel_bf(1) = g_x + k_x*sin(w_x*t - p_x)
@@ -86,7 +86,7 @@ contains
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    rhoM(j, k, l) = 0d0
+                    rhoM(j, k, l) = 0._wp
                     do i = 1, num_fluids
                         rhoM(j, k, l) = rhoM(j, k, l) + &
                                         q_cons_vf(contxb + i - 1)%sf(j, k, l)
@@ -117,7 +117,7 @@ contains
             do l = 0, p
                 do k = 0, n
                     do j = 0, m
-                        rhs_vf(i)%sf(j, k, l) = 0d0
+                        rhs_vf(i)%sf(j, k, l) = 0._wp
                     end do
                 end do
             end do
diff --git a/src/simulation/m_boundary_conditions.fpp b/src/simulation/m_boundary_conditions.fpp
index 266be8ed0..a15b14447 100644
--- a/src/simulation/m_boundary_conditions.fpp
+++ b/src/simulation/m_boundary_conditions.fpp
@@ -30,7 +30,7 @@ contains
     subroutine s_populate_variables_buffers(q_prim_vf, pb, mv)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
 
         integer :: bc_loc, bc_dir
 
@@ -217,7 +217,7 @@ contains
     subroutine s_ghost_cell_extrapolation(q_prim_vf, pb, mv, bc_dir, bc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
         integer :: j, k, l, q, i
 
@@ -328,7 +328,7 @@ contains
     subroutine s_symmetry(q_prim_vf, pb, mv, bc_dir, bc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
 
         integer :: j, k, l, q, i
@@ -610,7 +610,7 @@ contains
     subroutine s_periodic(q_prim_vf, pb, mv, bc_dir, bc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
 
         integer :: j, k, l, q, i
@@ -830,7 +830,7 @@ contains
     subroutine s_axis(q_prim_vf, pb, mv, bc_dir, bc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
 
         integer :: j, k, l, q, i
@@ -903,7 +903,7 @@ contains
     subroutine s_slip_wall(q_prim_vf, pb, mv, bc_dir, bc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
 
         integer :: j, k, l, q, i
@@ -920,7 +920,7 @@ contains
                             do j = 1, buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(-j, k, l) = &
-                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2d0*bc_x%vb1
+                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2._wp*bc_x%vb1
                                 else
                                     q_prim_vf(i)%sf(-j, k, l) = &
                                         q_prim_vf(i)%sf(0, k, l)
@@ -939,7 +939,7 @@ contains
                             do j = 1, buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(m + j, k, l) = &
-                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2d0*bc_x%ve1
+                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2._wp*bc_x%ve1
                                 else
                                     q_prim_vf(i)%sf(m + j, k, l) = &
                                         q_prim_vf(i)%sf(m, k, l)
@@ -963,7 +963,7 @@ contains
                             do l = -buff_size, m + buff_size
                                 if (i == momxb + 1) then
                                     q_prim_vf(i)%sf(l, -j, k) = &
-                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2d0*bc_y%vb2
+                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2._wp*bc_y%vb2
                                 else
                                     q_prim_vf(i)%sf(l, -j, k) = &
                                         q_prim_vf(i)%sf(l, 0, k)
@@ -982,7 +982,7 @@ contains
                             do l = -buff_size, m + buff_size
                                 if (i == momxb + 1) then
                                     q_prim_vf(i)%sf(l, n + j, k) = &
-                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2d0*bc_y%ve2
+                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2._wp*bc_y%ve2
                                 else
                                     q_prim_vf(i)%sf(l, n + j, k) = &
                                         q_prim_vf(i)%sf(l, n, k)
@@ -1006,7 +1006,7 @@ contains
                             do k = -buff_size, m + buff_size
                                 if (i == momxe) then
                                     q_prim_vf(i)%sf(k, l, -j) = &
-                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2d0*bc_z%vb3
+                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2._wp*bc_z%vb3
                                 else
                                     q_prim_vf(i)%sf(k, l, -j) = &
                                         q_prim_vf(i)%sf(k, l, 0)
@@ -1025,7 +1025,7 @@ contains
                             do k = -buff_size, m + buff_size
                                 if (i == momxe) then
                                     q_prim_vf(i)%sf(k, l, p + j) = &
-                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2d0*bc_z%ve3
+                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2._wp*bc_z%ve3
                                 else
                                     q_prim_vf(i)%sf(k, l, p + j) = &
                                         q_prim_vf(i)%sf(k, l, p)
@@ -1045,7 +1045,7 @@ contains
     subroutine s_no_slip_wall(q_prim_vf, pb, mv, bc_dir, bc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
 
         integer :: j, k, l, q, i
@@ -1062,13 +1062,13 @@ contains
                             do j = 1, buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(-j, k, l) = &
-                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2d0*bc_x%vb1
+                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2._wp*bc_x%vb1
                                 elseif (i == momxb + 1 .and. num_dims > 1) then
                                     q_prim_vf(i)%sf(-j, k, l) = &
-                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2d0*bc_x%vb2
+                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2._wp*bc_x%vb2
                                 elseif (i == momxb + 2 .and. num_dims > 2) then
                                     q_prim_vf(i)%sf(-j, k, l) = &
-                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2d0*bc_x%vb3
+                                        -q_prim_vf(i)%sf(j - 1, k, l) + 2._wp*bc_x%vb3
                                 else
                                     q_prim_vf(i)%sf(-j, k, l) = &
                                         q_prim_vf(i)%sf(0, k, l)
@@ -1087,13 +1087,13 @@ contains
                             do j = 1, buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(m + j, k, l) = &
-                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2d0*bc_x%ve1
+                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2._wp*bc_x%ve1
                                 elseif (i == momxb + 1 .and. num_dims > 1) then
                                     q_prim_vf(i)%sf(m + j, k, l) = &
-                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2d0*bc_x%ve2
+                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2._wp*bc_x%ve2
                                 elseif (i == momxb + 2 .and. num_dims > 2) then
                                     q_prim_vf(i)%sf(m + j, k, l) = &
-                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2d0*bc_x%ve3
+                                        -q_prim_vf(i)%sf(m - (j - 1), k, l) + 2._wp*bc_x%ve3
                                 else
                                     q_prim_vf(i)%sf(m + j, k, l) = &
                                         q_prim_vf(i)%sf(m, k, l)
@@ -1117,13 +1117,13 @@ contains
                             do l = -buff_size, m + buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(l, -j, k) = &
-                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2d0*bc_y%vb1
+                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2._wp*bc_y%vb1
                                 elseif (i == momxb + 1 .and. num_dims > 1) then
                                     q_prim_vf(i)%sf(l, -j, k) = &
-                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2d0*bc_y%vb2
+                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2._wp*bc_y%vb2
                                 elseif (i == momxb + 2 .and. num_dims > 2) then
                                     q_prim_vf(i)%sf(l, -j, k) = &
-                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2d0*bc_y%vb3
+                                        -q_prim_vf(i)%sf(l, j - 1, k) + 2._wp*bc_y%vb3
                                 else
                                     q_prim_vf(i)%sf(l, -j, k) = &
                                         q_prim_vf(i)%sf(l, 0, k)
@@ -1142,13 +1142,13 @@ contains
                             do l = -buff_size, m + buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(l, n + j, k) = &
-                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2d0*bc_y%ve1
+                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2._wp*bc_y%ve1
                                 elseif (i == momxb + 1 .and. num_dims > 1) then
                                     q_prim_vf(i)%sf(l, n + j, k) = &
-                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2d0*bc_y%ve2
+                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2._wp*bc_y%ve2
                                 elseif (i == momxb + 2 .and. num_dims > 2) then
                                     q_prim_vf(i)%sf(l, n + j, k) = &
-                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2d0*bc_y%ve3
+                                        -q_prim_vf(i)%sf(l, n - (j - 1), k) + 2._wp*bc_y%ve3
                                 else
                                     q_prim_vf(i)%sf(l, n + j, k) = &
                                         q_prim_vf(i)%sf(l, n, k)
@@ -1172,13 +1172,13 @@ contains
                             do k = -buff_size, m + buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(k, l, -j) = &
-                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2d0*bc_z%vb1
+                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2._wp*bc_z%vb1
                                 elseif (i == momxb + 1 .and. num_dims > 1) then
                                     q_prim_vf(i)%sf(k, l, -j) = &
-                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2d0*bc_z%vb2
+                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2._wp*bc_z%vb2
                                 elseif (i == momxb + 2 .and. num_dims > 2) then
                                     q_prim_vf(i)%sf(k, l, -j) = &
-                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2d0*bc_z%vb3
+                                        -q_prim_vf(i)%sf(k, l, j - 1) + 2._wp*bc_z%vb3
                                 else
                                     q_prim_vf(i)%sf(k, l, -j) = &
                                         q_prim_vf(i)%sf(k, l, 0)
@@ -1197,13 +1197,13 @@ contains
                             do k = -buff_size, m + buff_size
                                 if (i == momxb) then
                                     q_prim_vf(i)%sf(k, l, p + j) = &
-                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2d0*bc_z%ve1
+                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2._wp*bc_z%ve1
                                 elseif (i == momxb + 1 .and. num_dims > 1) then
                                     q_prim_vf(i)%sf(k, l, p + j) = &
-                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2d0*bc_z%ve2
+                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2._wp*bc_z%ve2
                                 elseif (i == momxb + 2 .and. num_dims > 2) then
                                     q_prim_vf(i)%sf(k, l, p + j) = &
-                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2d0*bc_z%ve3
+                                        -q_prim_vf(i)%sf(k, l, p - (j - 1)) + 2._wp*bc_z%ve3
                                 else
                                     q_prim_vf(i)%sf(k, l, p + j) = &
                                         q_prim_vf(i)%sf(k, l, p)
@@ -1222,7 +1222,7 @@ contains
 
     subroutine s_qbmm_extrapolation(pb, mv, bc_dir, bc_loc)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: bc_dir, bc_loc
 
         integer :: j, k, l, q, i
diff --git a/src/simulation/m_bubbles.fpp b/src/simulation/m_bubbles.fpp
index b0027f42c..4beb03352 100644
--- a/src/simulation/m_bubbles.fpp
+++ b/src/simulation/m_bubbles.fpp
@@ -21,13 +21,13 @@ module m_bubbles
 
     implicit none
 
-    real(kind(0.d0)) :: chi_vw  !< Bubble wall properties (Ando 2010)
-    real(kind(0.d0)) :: k_mw    !< Bubble wall properties (Ando 2010)
-    real(kind(0.d0)) :: rho_mw  !< Bubble wall properties (Ando 2010)
+    real(wp) :: chi_vw  !< Bubble wall properties (Ando 2010)
+    real(wp) :: k_mw    !< Bubble wall properties (Ando 2010)
+    real(wp) :: rho_mw  !< Bubble wall properties (Ando 2010)
     !$acc declare create(chi_vw, k_mw, rho_mw)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: bub_adv_src
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: bub_r_src, bub_v_src, bub_p_src, bub_m_src
+    real(wp), allocatable, dimension(:, :, :) :: bub_adv_src
+    real(wp), allocatable, dimension(:, :, :, :) :: bub_r_src, bub_v_src, bub_p_src, bub_m_src
     !$acc declare create(bub_adv_src, bub_r_src, bub_v_src, bub_p_src, bub_m_src)
 
     type(scalar_field) :: divu !< matrix for div(u)
@@ -78,19 +78,19 @@ contains
         !! @param q_cons_vf is the conservative variable
     subroutine s_comp_alpha_from_n(q_cons_vf)
         type(scalar_field), dimension(sys_size), intent(inout) :: q_cons_vf
-        real(kind(0d0)) :: nR3bar
-        integer(kind(0d0)) :: i, j, k, l
+        real(wp) :: nR3bar
+        integer(wp) :: i, j, k, l
 
         !$acc parallel loop collapse(3) gang vector default(present)
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    nR3bar = 0d0
+                    nR3bar = 0._wp
                     !$acc loop seq
                     do i = 1, nb
-                        nR3bar = nR3bar + weight(i)*(q_cons_vf(rs(i))%sf(j, k, l))**3d0
+                        nR3bar = nR3bar + weight(i)*(q_cons_vf(rs(i))%sf(j, k, l))**3._wp
                     end do
-                    q_cons_vf(alf_idx)%sf(j, k, l) = (4d0*pi*nR3bar)/(3d0*q_cons_vf(n_idx)%sf(j, k, l)**2d0)
+                    q_cons_vf(alf_idx)%sf(j, k, l) = (4._wp*pi*nR3bar)/(3._wp*q_cons_vf(n_idx)%sf(j, k, l)**2._wp)
                 end do
             end do
         end do
@@ -111,10 +111,10 @@ contains
                 do l = 0, p
                     do k = 0, n
                         do j = 0, m
-                            divu%sf(j, k, l) = 0d0
+                            divu%sf(j, k, l) = 0._wp
                             divu%sf(j, k, l) = &
-                                5d-1/dx(j)*(q_prim_vf(contxe + idir)%sf(j + 1, k, l) - &
-                                            q_prim_vf(contxe + idir)%sf(j - 1, k, l))
+                                5e-1_wp/dx(j)*(q_prim_vf(contxe + idir)%sf(j + 1, k, l) - &
+                                               q_prim_vf(contxe + idir)%sf(j - 1, k, l))
 
                         end do
                     end do
@@ -128,8 +128,8 @@ contains
                 do k = 0, n
                     do j = 0, m
                         divu%sf(j, k, l) = divu%sf(j, k, l) + &
-                                           5d-1/dy(k)*(q_prim_vf(contxe + idir)%sf(j, k + 1, l) - &
-                                                       q_prim_vf(contxe + idir)%sf(j, k - 1, l))
+                                           5e-1_wp/dy(k)*(q_prim_vf(contxe + idir)%sf(j, k + 1, l) - &
+                                                          q_prim_vf(contxe + idir)%sf(j, k - 1, l))
 
                     end do
                 end do
@@ -142,8 +142,8 @@ contains
                 do k = 0, n
                     do j = 0, m
                         divu%sf(j, k, l) = divu%sf(j, k, l) + &
-                                           5d-1/dz(l)*(q_prim_vf(contxe + idir)%sf(j, k, l + 1) - &
-                                                       q_prim_vf(contxe + idir)%sf(j, k, l - 1))
+                                           5e-1_wp/dz(l)*(q_prim_vf(contxe + idir)%sf(j, k, l + 1) - &
+                                                          q_prim_vf(contxe + idir)%sf(j, k, l - 1))
 
                     end do
                 end do
@@ -163,32 +163,33 @@ contains
         integer, intent(in) :: t_step
         type(scalar_field), dimension(sys_size), intent(inout) :: rhs_vf
 
-        real(kind(0d0)) :: rddot
-        real(kind(0d0)) :: pb, mv, vflux, pbdot
-        real(kind(0d0)) :: n_tait, B_tait
-        real(kind(0d0)), dimension(nb) :: Rtmp, Vtmp
-        real(kind(0d0)) :: myR, myV, alf, myP, myRho, R2Vav, R3
-        real(kind(0d0)), dimension(num_fluids) :: myalpha, myalpha_rho
-        real(kind(0d0)) :: nbub !< Bubble number density
+        real(wp) :: rddot
+        real(wp) :: pb, mv, vflux, pbdot
+        real(wp) :: n_tait, B_tait
+        real(wp), dimension(nb) :: Rtmp, Vtmp
+        real(wp) :: myR, myV, alf, myP, myRho, R2Vav, R3
+        real(wp), dimension(num_fluids) :: myalpha, myalpha_rho
+        real(wp) :: nbub !< Bubble number density
+
         integer :: i, j, k, l, q, ii !< Loop variables
 
-        real(kind(0d0)) :: err1, err2, err3, err4, err5 !< Error estimates for adaptive time stepping
-        real(kind(0d0)) :: t_new !< Updated time step size
-        real(kind(0d0)) :: h !< Time step size
-        real(kind(0d0)), dimension(4) :: myR_tmp1, myV_tmp1, myR_tmp2, myV_tmp2 !< Bubble radius, radial velocity, and radial acceleration for the inner loop
+        real(wp) :: err1, err2, err3, err4, err5 !< Error estimates for adaptive time stepping
+        real(wp) :: t_new !< Updated time step size
+        real(wp) :: h !< Time step size
+        real(wp), dimension(4) :: myR_tmp1, myV_tmp1, myR_tmp2, myV_tmp2 !< Bubble radius, radial velocity, and radial acceleration for the inner loop
 
         !$acc parallel loop collapse(3) gang vector default(present)
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    bub_adv_src(j, k, l) = 0d0
+                    bub_adv_src(j, k, l) = 0._wp
 
                     !$acc loop seq
                     do q = 1, nb
-                        bub_r_src(j, k, l, q) = 0d0
-                        bub_v_src(j, k, l, q) = 0d0
-                        bub_p_src(j, k, l, q) = 0d0
-                        bub_m_src(j, k, l, q) = 0d0
+                        bub_r_src(j, k, l, q) = 0._wp
+                        bub_v_src(j, k, l, q) = 0._wp
+                        bub_p_src(j, k, l, q) = 0._wp
+                        bub_m_src(j, k, l, q) = 0._wp
                     end do
                 end do
             end do
@@ -208,25 +209,25 @@ contains
                             Vtmp(q) = q_prim_vf(vs(q))%sf(j, k, l)
                         end do
 
-                        R3 = 0d0
+                        R3 = 0._wp
 
                         !$acc loop seq
                         do q = 1, nb
-                            R3 = R3 + weight(q)*Rtmp(q)**3.d0
+                            R3 = R3 + weight(q)*Rtmp(q)**3._wp
                         end do
 
-                        nbub = (3.d0/(4.d0*pi))*q_prim_vf(alf_idx)%sf(j, k, l)/R3
+                        nbub = (3._wp/(4._wp*pi))*q_prim_vf(alf_idx)%sf(j, k, l)/R3
                     end if
 
                     if (.not. adap_dt) then
-                        R2Vav = 0d0
+                        R2Vav = 0._wp
 
                         !$acc loop seq
                         do q = 1, nb
-                            R2Vav = R2Vav + weight(q)*Rtmp(q)**2.d0*Vtmp(q)
+                            R2Vav = R2Vav + weight(q)*Rtmp(q)**2._wp*Vtmp(q)
                         end do
 
-                        bub_adv_src(j, k, l) = 4.d0*pi*nbub*R2Vav
+                        bub_adv_src(j, k, l) = 4._wp*pi*nbub*R2Vav
                     end if
 
                     !$acc loop seq
@@ -238,9 +239,9 @@ contains
                             myalpha(ii) = q_cons_vf(advxb + ii - 1)%sf(j, k, l)
                         end do
 
-                        myRho = 0d0
-                        n_tait = 0d0
-                        B_tait = 0d0
+                        myRho = 0._wp
+                        n_tait = 0._wp
+                        B_tait = 0._wp
 
                         if (mpp_lim .and. (num_fluids > 2)) then
                             !$acc loop seq
@@ -262,7 +263,7 @@ contains
                             B_tait = pi_infs(1)/pi_fac
                         end if
 
-                        n_tait = 1.d0/n_tait + 1.d0 !make this the usual little 'gamma'
+                        n_tait = 1._wp/n_tait + 1._wp !make this the usual little 'gamma'
                         B_tait = B_tait*(n_tait - 1)/n_tait ! make this the usual pi_inf
 
                         myRho = q_prim_vf(1)%sf(j, k, l)
@@ -279,9 +280,9 @@ contains
                             pbdot = f_bpres_dot(vflux, myR, myV, pb, mv, q)
 
                             bub_p_src(j, k, l, q) = nbub*pbdot
-                            bub_m_src(j, k, l, q) = nbub*vflux*4.d0*pi*(myR**2.d0)
+                            bub_m_src(j, k, l, q) = nbub*vflux*4._wp*pi*(myR**2._wp)
                         else
-                            pb = 0d0; mv = 0d0; vflux = 0d0; pbdot = 0d0
+                            pb = 0._wp; mv = 0._wp; vflux = 0._wp; pbdot = 0._wp
                         end if
 
                         ! Adaptive time stepping
@@ -292,10 +293,10 @@ contains
                                                       bub_adv_src(j, k, l), divu%sf(j, k, l), h)
 
                             ! Advancing one step
-                            t_new = 0d0
+                            t_new = 0._wp
                             do while (.true.)
-                                if (t_new + h > 0.5d0*dt) then
-                                    h = 0.5d0*dt - t_new
+                                if (t_new + h > 0.5_wp*dt) then
+                                    h = 0.5_wp*dt - t_new
                                 end if
 
                                 ! Advancing one sub-step
@@ -309,26 +310,26 @@ contains
                                     ! Advance one sub-step by advancing two half steps
                                     call s_advance_substep(myRho, myP, myR, myV, R0(q), &
                                                            pb, pbdot, alf, n_tait, B_tait, &
-                                                           bub_adv_src(j, k, l), divu%sf(j, k, l), 0.5d0*h, &
+                                                           bub_adv_src(j, k, l), divu%sf(j, k, l), 0.5_wp*h, &
                                                            myR_tmp2, myV_tmp2, err2)
 
                                     call s_advance_substep(myRho, myP, myR_tmp2(4), myV_tmp2(4), R0(q), &
                                                            pb, pbdot, alf, n_tait, B_tait, &
-                                                           bub_adv_src(j, k, l), divu%sf(j, k, l), 0.5d0*h, &
+                                                           bub_adv_src(j, k, l), divu%sf(j, k, l), 0.5_wp*h, &
                                                            myR_tmp2, myV_tmp2, err3)
 
                                     err4 = abs((myR_tmp1(4) - myR_tmp2(4))/myR_tmp1(4))
                                     err5 = abs((myV_tmp1(4) - myV_tmp2(4))/myV_tmp1(4))
-                                    if (abs(myV_tmp1(4)) < 1e-12) err5 = 0d0
+                                    if (abs(myV_tmp1(4)) < 1e-12_wp) err5 = 0._wp
 
                                     ! Determine acceptance/rejection and update step size
                                     !   Rule 1: err1, err2, err3 < tol
-                                    !   Rule 2: myR_tmp1(4) > 0d0
+                                    !   Rule 2: myR_tmp1(4) > 0._wp
                                     !   Rule 3: abs((myR_tmp1(4) - myR_tmp2(4))/myR) < tol
                                     !   Rule 4: abs((myV_tmp1(4) - myV_tmp2(4))/myV) < tol
-                                    if ((err1 <= 1d-4) .and. (err2 <= 1d-4) .and. (err3 <= 1d-4) &
-                                        .and. (err4 < 1d-4) .and. (err5 < 1d-4) &
-                                        .and. myR_tmp1(4) > 0d0) then
+                                    if ((err1 <= 1e-4_wp) .and. (err2 <= 1e-4_wp) .and. (err3 <= 1e-4_wp) &
+                                        .and. (err4 < 1e-4_wp) .and. (err5 < 1e-4_wp) &
+                                        .and. myR_tmp1(4) > 0._wp) then
 
                                         ! Accepted. Finalize the sub-step
                                         t_new = t_new + h
@@ -338,22 +339,22 @@ contains
                                         myV = myV_tmp1(4)
 
                                         ! Update step size for the next sub-step
-                                        h = h*min(2d0, max(0.5d0, (1d-4/err1)**(1d0/3d0)))
+                                        h = h*min(2._wp, max(0.5_wp, (1e-4_wp/err1)**(1._wp/3._wp)))
 
                                         exit
                                     else
                                         ! Rejected. Update step size for the next try on sub-step
-                                        if (err2 <= 1d-4) then
-                                            h = 0.5d0*h
+                                        if (err2 <= 1e-4_wp) then
+                                            h = 0.5_wp*h
                                         else
-                                            h = 0.25d0*h
+                                            h = 0.25_wp*h
                                         end if
 
                                     end if
                                 end do
 
                                 ! Exit the loop if the final time reached dt
-                                if (t_new == 0.5d0*dt) exit
+                                if (t_new == 0.5_wp*dt) exit
 
                             end do
 
@@ -368,13 +369,13 @@ contains
                             bub_r_src(j, k, l, q) = q_cons_vf(vs(q))%sf(j, k, l)
                         end if
 
-                        if (alf < 1.d-11) then
-                            bub_adv_src(j, k, l) = 0d0
-                            bub_r_src(j, k, l, q) = 0d0
-                            bub_v_src(j, k, l, q) = 0d0
+                        if (alf < 1.e-11_wp) then
+                            bub_adv_src(j, k, l) = 0._wp
+                            bub_r_src(j, k, l, q) = 0._wp
+                            bub_v_src(j, k, l, q) = 0._wp
                             if (.not. polytropic) then
-                                bub_p_src(j, k, l, q) = 0d0
-                                bub_m_src(j, k, l, q) = 0d0
+                                bub_p_src(j, k, l, q) = 0._wp
+                                bub_m_src(j, k, l, q) = 0._wp
                             end if
                         end if
                     end do
@@ -424,13 +425,13 @@ contains
     subroutine s_initialize_adap_dt(fRho, fP, fR, fV, fR0, fpb, fpbdot, alf, &
                                     fntait, fBtait, f_bub_adv_src, f_divu, h)
         !$acc routine seq
-        real(kind(0d0)), intent(IN) :: fRho, fP, fR, fV, fR0, fpb, fpbdot, alf
-        real(kind(0d0)), intent(IN) :: fntait, fBtait, f_bub_adv_src, f_divu
-        real(kind(0d0)), intent(out) :: h
+        real(wp), intent(IN) :: fRho, fP, fR, fV, fR0, fpb, fpbdot, alf
+        real(wp), intent(IN) :: fntait, fBtait, f_bub_adv_src, f_divu
+        real(wp), intent(out) :: h
 
-        real(kind(0d0)) :: h0, h1 !< Time step size
-        real(kind(0d0)) :: d0, d1, d2 !< norms
-        real(kind(0d0)), dimension(2) :: myR_tmp, myV_tmp, myA_tmp !< Bubble radius, radial velocity, and radial acceleration
+        real(wp) :: h0, h1 !< Time step size
+        real(wp) :: d0, d1, d2 !< norms
+        real(wp), dimension(2) :: myR_tmp, myV_tmp, myA_tmp !< Bubble radius, radial velocity, and radial acceleration
 
         ! Determine the starting time step
         ! Evaluate f(x0,y0)
@@ -441,12 +442,12 @@ contains
                              f_bub_adv_src, f_divu)
 
         ! Compute d0 = ||y0|| and d1 = ||f(x0,y0)||
-        d0 = DSQRT((myR_tmp(1)**2d0 + myV_tmp(1)**2d0)/2d0)
-        d1 = DSQRT((myV_tmp(1)**2d0 + myA_tmp(1)**2d0)/2d0)
-        if (d0 < 1d-5 .or. d1 < 1d-5) then
-            h0 = 1d-6
+        d0 = sqrt((myR_tmp(1)**2._wp + myV_tmp(1)**2._wp)/2._wp)
+        d1 = sqrt((myV_tmp(1)**2._wp + myA_tmp(1)**2._wp)/2._wp)
+        if (d0 < 1e-5_wp .or. d1 < 1e-5_wp) then
+            h0 = 1e-6_wp
         else
-            h0 = 1d-2*(d0/d1)
+            h0 = 1e-2_wp*(d0/d1)
         end if
 
         ! Evaluate f(x0+h0,y0+h0*f(x0,y0))
@@ -457,18 +458,18 @@ contains
                              f_bub_adv_src, f_divu)
 
         ! Compute d2 = ||f(x0+h0,y0+h0*f(x0,y0))-f(x0,y0)||/h0
-        d2 = DSQRT(((myV_tmp(2) - myV_tmp(1))**2d0 + (myA_tmp(2) - myA_tmp(1))**2d0)/2d0)/h0
+        d2 = sqrt(((myV_tmp(2) - myV_tmp(1))**2._wp + (myA_tmp(2) - myA_tmp(1))**2._wp)/2._wp)/h0
 
         ! Set h1 = (0.01/max(d1,d2))^{1/(p+1)}
-        !      if max(d1,d2) < 1e-15, h1 = max(1e-6, h0*1e-3)
-        if (max(d1, d2) < 1d-15) then
-            h1 = max(1d-6, h0*1d-3)
+        !      if max(d1,d2) < 1e-15_wp, h1 = max(1e-6_wp, h0*1e-3_wp)
+        if (max(d1, d2) < 1e-15_wp) then
+            h1 = max(1e-6_wp, h0*1e-3_wp)
         else
-            h1 = (1d-2/max(d1, d2))**(1d0/3d0)
+            h1 = (1e-2_wp/max(d1, d2))**(1._wp/3._wp)
         end if
 
         ! Set h = min(100*h0,h1)
-        h = min(100d0*h0, h1)
+        h = min(100._wp*h0, h1)
 
     end subroutine s_initialize_adap_dt
 
@@ -493,12 +494,12 @@ contains
                                  fntait, fBtait, f_bub_adv_src, f_divu, h, &
                                  myR_tmp, myV_tmp, err)
         !$acc routine seq
-        real(kind(0d0)), intent(IN) :: fRho, fP, fR, fV, fR0, fpb, fpbdot, alf
-        real(kind(0d0)), intent(IN) :: fntait, fBtait, f_bub_adv_src, f_divu, h
-        real(kind(0d0)), dimension(4), intent(OUT) :: myR_tmp, myV_tmp
-        real(kind(0d0)), dimension(4) :: myA_tmp
-        real(kind(0d0)), intent(OUT) :: err
-        real(kind(0d0)) :: err_R, err_V
+        real(wp), intent(IN) :: fRho, fP, fR, fV, fR0, fpb, fpbdot, alf
+        real(wp), intent(IN) :: fntait, fBtait, f_bub_adv_src, f_divu, h
+        real(wp), dimension(4), intent(OUT) :: myR_tmp, myV_tmp
+        real(wp), dimension(4) :: myA_tmp
+        real(wp), intent(OUT) :: err
+        real(wp) :: err_R, err_V
 
         ! Stage 0
         myR_tmp(1) = fR
@@ -515,25 +516,25 @@ contains
                              f_bub_adv_src, f_divu)
 
         ! Stage 2
-        myR_tmp(3) = myR_tmp(1) + (h/4d0)*(myV_tmp(1) + myV_tmp(2))
-        myV_tmp(3) = myV_tmp(1) + (h/4d0)*(myA_tmp(1) + myA_tmp(2))
+        myR_tmp(3) = myR_tmp(1) + (h/4._wp)*(myV_tmp(1) + myV_tmp(2))
+        myV_tmp(3) = myV_tmp(1) + (h/4._wp)*(myA_tmp(1) + myA_tmp(2))
         myA_tmp(3) = f_rddot(fRho, fP, myR_tmp(3), myV_tmp(3), fR0, &
                              fpb, fpbdot, alf, fntait, fBtait, &
                              f_bub_adv_src, f_divu)
 
         ! Stage 3
-        myR_tmp(4) = myR_tmp(1) + (h/6d0)*(myV_tmp(1) + myV_tmp(2) + 4d0*myV_tmp(3))
-        myV_tmp(4) = myV_tmp(1) + (h/6d0)*(myA_tmp(1) + myA_tmp(2) + 4d0*myA_tmp(3))
+        myR_tmp(4) = myR_tmp(1) + (h/6._wp)*(myV_tmp(1) + myV_tmp(2) + 4._wp*myV_tmp(3))
+        myV_tmp(4) = myV_tmp(1) + (h/6._wp)*(myA_tmp(1) + myA_tmp(2) + 4._wp*myA_tmp(3))
         myA_tmp(4) = f_rddot(fRho, fP, myR_tmp(4), myV_tmp(4), fR0, &
                              fpb, fpbdot, alf, fntait, fBtait, &
                              f_bub_adv_src, f_divu)
 
         ! Estimate error
-        err_R = (-5d0*h/24d0)*(myV_tmp(2) + myV_tmp(3) - 2d0*myV_tmp(4)) &
+        err_R = (-5._wp*h/24._wp)*(myV_tmp(2) + myV_tmp(3) - 2._wp*myV_tmp(4)) &
                 /max(abs(myR_tmp(1)), abs(myR_tmp(4)))
-        err_V = (-5d0*h/24d0)*(myA_tmp(2) + myA_tmp(3) - 2d0*myA_tmp(4)) &
+        err_V = (-5._wp*h/24._wp)*(myA_tmp(2) + myA_tmp(3) - 2._wp*myA_tmp(4)) &
                 /max(abs(myV_tmp(1)), abs(myV_tmp(4)))
-        err = DSQRT((err_R**2d0 + err_V**2d0)/2d0)
+        err = sqrt((err_R**2._wp + err_V**2._wp)/2._wp)
 
     end subroutine s_advance_substep
 
@@ -544,14 +545,14 @@ contains
         !!  @param fpb Internal bubble pressure
     function f_cpbw(fR0, fR, fV, fpb)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fR0, fR, fV, fpb
+        real(wp), intent(in) :: fR0, fR, fV, fpb
 
-        real(kind(0d0)) :: f_cpbw
+        real(wp) :: f_cpbw
 
         if (polytropic) then
-            f_cpbw = (Ca + 2.d0/Web/fR0)*((fR0/fR)**(3.d0*gam)) - Ca - 4.d0*Re_inv*fV/fR - 2.d0/(fR*Web)
+            f_cpbw = (Ca + 2._wp/Web/fR0)*((fR0/fR)**(3._wp*gam)) - Ca - 4._wp*Re_inv*fV/fR - 2._wp/(fR*Web)
         else
-            f_cpbw = fpb - 1.d0 - 4.d0*Re_inv*fV/fR - 2.d0/(fR*Web)
+            f_cpbw = fpb - 1._wp - 4._wp*Re_inv*fV/fR - 2._wp/(fR*Web)
         end if
 
     end function f_cpbw
@@ -563,16 +564,16 @@ contains
         !!  @param fBtait Tait EOS parameter
     function f_H(fCpbw, fCpinf, fntait, fBtait)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fCpbw, fCpinf, fntait, fBtait
+        real(wp), intent(in) :: fCpbw, fCpinf, fntait, fBtait
 
-        real(kind(0d0)) :: tmp1, tmp2, tmp3
-        real(kind(0d0)) :: f_H
+        real(wp) :: tmp1, tmp2, tmp3
+        real(wp) :: f_H
 
-        tmp1 = (fntait - 1.d0)/fntait
-        tmp2 = (fCpbw/(1.d0 + fBtait) + 1.d0)**tmp1
-        tmp3 = (fCpinf/(1.d0 + fBtait) + 1.d0)**tmp1
+        tmp1 = (fntait - 1._wp)/fntait
+        tmp2 = (fCpbw/(1._wp + fBtait) + 1._wp)**tmp1
+        tmp3 = (fCpinf/(1._wp + fBtait) + 1._wp)**tmp1
 
-        f_H = (tmp2 - tmp3)*fntait*(1.d0 + fBtait)/(fntait - 1.d0)
+        f_H = (tmp2 - tmp3)*fntait*(1._wp + fBtait)/(fntait - 1._wp)
 
     end function f_H
 
@@ -583,16 +584,16 @@ contains
         !! @param fH Bubble enthalpy
     function f_cgas(fCpinf, fntait, fBtait, fH)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fCpinf, fntait, fBtait, fH
+        real(wp), intent(in) :: fCpinf, fntait, fBtait, fH
 
-        real(kind(0d0)) :: tmp
-        real(kind(0d0)) :: f_cgas
+        real(wp) :: tmp
+        real(wp) :: f_cgas
 
         ! get sound speed for Gilmore equations "C" -> c_gas
-        tmp = (fCpinf/(1.d0 + fBtait) + 1.d0)**((fntait - 1.d0)/fntait)
-        tmp = fntait*(1.d0 + fBtait)*tmp
+        tmp = (fCpinf/(1._wp + fBtait) + 1._wp)**((fntait - 1._wp)/fntait)
+        tmp = fntait*(1._wp + fBtait)*tmp
 
-        f_cgas = dsqrt(tmp + (fntait - 1.d0)*fH)
+        f_cgas = sqrt(tmp + (fntait - 1._wp)*fH)
 
     end function f_cgas
 
@@ -606,17 +607,17 @@ contains
         !!  @param divu Divergence of velocity
     function f_cpinfdot(fRho, fP, falf, fntait, fBtait, advsrc, divu)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fRho, fP, falf, fntait, fBtait, advsrc, divu
+        real(wp), intent(in) :: fRho, fP, falf, fntait, fBtait, advsrc, divu
 
-        real(kind(0d0)) :: c2_liquid
-        real(kind(0d0)) :: f_cpinfdot
+        real(wp) :: c2_liquid
+        real(wp) :: f_cpinfdot
 
         ! get sound speed squared for liquid (only needed for pbdot)
         ! c_l^2 = gam (p+B) / (rho*(1-alf))
         if (mpp_lim) then
             c2_liquid = fntait*(fP + fBtait)/fRho
         else
-            c2_liquid = fntait*(fP + fBtait)/(fRho*(1.d0 - falf))
+            c2_liquid = fntait*(fP + fBtait)/(fRho*(1._wp - falf))
         end if
 
         ! \dot{Cp_inf} = rho sound^2 (alf_src - divu)
@@ -636,30 +637,30 @@ contains
         !!  @param fpbdot Time derivative of the internal bubble pressure
     function f_Hdot(fCpbw, fCpinf, fCpinf_dot, fntait, fBtait, fR, fV, fR0, fpbdot)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fCpbw, fCpinf, fCpinf_dot, fntait, fBtait
-        real(kind(0d0)), intent(in) :: fR, fV, fR0, fpbdot
+        real(wp), intent(in) :: fCpbw, fCpinf, fCpinf_dot, fntait, fBtait
+        real(wp), intent(in) :: fR, fV, fR0, fpbdot
 
-        real(kind(0d0)) :: tmp1, tmp2
-        real(kind(0d0)) :: f_Hdot
+        real(wp) :: tmp1, tmp2
+        real(wp) :: f_Hdot
 
         if (polytropic) then
-            tmp1 = (fR0/fR)**(3.d0*gam)
-            tmp1 = -3.d0*gam*(Ca + 2d0/Web/fR0)*tmp1*fV/fR
+            tmp1 = (fR0/fR)**(3._wp*gam)
+            tmp1 = -3._wp*gam*(Ca + 2._wp/Web/fR0)*tmp1*fV/fR
         else
             tmp1 = fpbdot
         end if
-        tmp2 = (2.d0/Web + 4.d0*Re_inv*fV)*fV/(fR**2.d0)
+        tmp2 = (2._wp/Web + 4._wp*Re_inv*fV)*fV/(fR**2._wp)
 
         f_Hdot = &
-            (fCpbw/(1.d0 + fBtait) + 1.d0)**(-1.d0/fntait)*(tmp1 + tmp2) &
-            - (fCpinf/(1.d0 + fBtait) + 1.d0)**(-1.d0/fntait)*fCpinf_dot
+            (fCpbw/(1._wp + fBtait) + 1._wp)**(-1._wp/fntait)*(tmp1 + tmp2) &
+            - (fCpinf/(1._wp + fBtait) + 1._wp)**(-1._wp/fntait)*fCpinf_dot
 
         ! Hdot = (Cpbw/(1+B) + 1)^(-1/n_tait)*(-3 gam)*(R0/R)^(3gam) V/R
-        !f_Hdot = ((fCpbw/(1d0+fBtait)+1.d0)**(-1.d0/fntait))*(-3.d0)*gam * &
-        !            ( (fR0/fR)**(3.d0*gam ))*(fV/fR)
+        !f_Hdot = ((fCpbw/(1._wp+fBtait)+1._wp)**(-1._wp/fntait))*(-3._wp)*gam * &
+        !            ( (fR0/fR)**(3._wp*gam ))*(fV/fR)
 
         ! Hdot = Hdot - (Cpinf/(1+B) + 1)^(-1/n_tait) Cpinfdot
-        !f_Hdot = f_Hdot - ((fCpinf/(1.d0+fBtait)+1.d0)**(-1.d0/fntait))*fCpinf_dot
+        !f_Hdot = f_Hdot - ((fCpinf/(1._wp+fBtait)+1._wp)**(-1._wp/fntait))*fCpinf_dot
 
     end function f_Hdot
 
@@ -678,11 +679,11 @@ contains
         !!  @param f_divu Divergence of velocity
     function f_rddot(fRho, fP, fR, fV, fR0, fpb, fpbdot, alf, fntait, fBtait, f_bub_adv_src, f_divu)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fRho, fP, fR, fV, fR0, fpb, fpbdot, alf
-        real(kind(0d0)), intent(in) :: fntait, fBtait, f_bub_adv_src, f_divu
+        real(wp), intent(in) :: fRho, fP, fR, fV, fR0, fpb, fpbdot, alf
+        real(wp), intent(in) :: fntait, fBtait, f_bub_adv_src, f_divu
 
-        real(kind(0d0)) :: fCpbw, fCpinf, fCpinf_dot, fH, fHdot, c_gas, c_liquid
-        real(kind(0d0)) :: f_rddot
+        real(wp) :: fCpbw, fCpinf, fCpinf_dot, fH, fHdot, c_gas, c_liquid
+        real(wp) :: f_rddot
 
         if (bubble_model == 1) then
             ! Gilmore bubbles
@@ -697,7 +698,7 @@ contains
             ! Keller-Miksis bubbles
             fCpinf = fP
             fCpbw = f_cpbw_KM(fR0, fR, fV, fpb)
-            c_liquid = dsqrt(fntait*(fP + fBtait)/(fRho*(1.d0 - alf)))
+            c_liquid = sqrt(fntait*(fP + fBtait)/(fRho*(1._wp - alf)))
             f_rddot = f_rddot_KM(fpbdot, fCpinf, fCpbw, fRho, fR, fV, fR0, c_liquid)
         else if (bubble_model == 3) then
             ! Rayleigh-Plesset bubbles
@@ -716,15 +717,15 @@ contains
         !!  @param fCpbw Boundary wall pressure
     function f_rddot_RP(fCp, fRho, fR, fV, fR0, fCpbw)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fCp, fRho, fR, fV, fR0, fCpbw
+        real(wp), intent(in) :: fCp, fRho, fR, fV, fR0, fCpbw
 
-        real(kind(0d0)) :: f_rddot_RP
+        real(wp) :: f_rddot_RP
 
             !! rddot = (1/r) (  -3/2 rdot^2 + ((r0/r)^3\gamma - Cp)/rho )
             !! rddot = (1/r) (  -3/2 rdot^2 + (tmp1 - Cp)/rho )
             !! rddot = (1/r) (  tmp2 )
 
-        f_rddot_RP = (-1.5d0*(fV**2d0) + (fCpbw - fCp)/fRho)/fR
+        f_rddot_RP = (-1.5_wp*(fV**2._wp) + (fCpbw - fCp)/fRho)/fR
 
     end function f_rddot_RP
 
@@ -739,19 +740,19 @@ contains
         !!  @param fBtait Tait EOS parameter
     function f_rddot_G(fCpbw, fR, fV, fH, fHdot, fcgas, fntait, fBtait)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fCpbw, fR, fV, fH, fHdot
-        real(kind(0d0)), intent(in) :: fcgas, fntait, fBtait
+        real(wp), intent(in) :: fCpbw, fR, fV, fH, fHdot
+        real(wp), intent(in) :: fcgas, fntait, fBtait
 
-        real(kind(0d0)) :: tmp1, tmp2, tmp3
-        real(kind(0d0)) :: f_rddot_G
+        real(wp) :: tmp1, tmp2, tmp3
+        real(wp) :: f_rddot_G
 
         tmp1 = fV/fcgas
-        tmp2 = 1.d0 + 4.d0*Re_inv/fcgas/fR*(fCpbw/(1.d0 + fBtait) + 1.d0) &
-               **(-1.d0/fntait)
-        tmp3 = 1.5d0*fV**2d0*(tmp1/3.d0 - 1.d0) + fH*(1.d0 + tmp1) &
-               + fR*fHdot*(1.d0 - tmp1)/fcgas
+        tmp2 = 1._wp + 4._wp*Re_inv/fcgas/fR*(fCpbw/(1._wp + fBtait) + 1._wp) &
+               **(-1._wp/fntait)
+        tmp3 = 1.5_wp*fV**2._wp*(tmp1/3._wp - 1._wp) + fH*(1._wp + tmp1) &
+               + fR*fHdot*(1._wp - tmp1)/fcgas
 
-        f_rddot_G = tmp3/(fR*(1.d0 - tmp1)*tmp2)
+        f_rddot_G = tmp3/(fR*(1._wp - tmp1)*tmp2)
 
     end function f_rddot_G
 
@@ -762,20 +763,20 @@ contains
         !!  @param fpb Internal bubble pressure
     function f_cpbw_KM(fR0, fR, fV, fpb)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fR0, fR, fV, fpb
+        real(wp), intent(in) :: fR0, fR, fV, fpb
 
-        real(kind(0d0)) :: f_cpbw_KM
+        real(wp) :: f_cpbw_KM
 
         if (polytropic) then
-            f_cpbw_KM = Ca*((fR0/fR)**(3.d0*gam)) - Ca + 1d0
+            f_cpbw_KM = Ca*((fR0/fR)**(3._wp*gam)) - Ca + 1._wp
             if (.not. f_is_default(Web)) f_cpbw_KM = f_cpbw_KM + &
-                                                     (2.d0/(Web*fR0))*((fR0/fR)**(3.d0*gam))
+                                                     (2._wp/(Web*fR0))*((fR0/fR)**(3._wp*gam))
         else
             f_cpbw_KM = fpb
         end if
 
-        if (.not. f_is_default(Web)) f_cpbw_KM = f_cpbw_KM - 2.d0/(fR*Web)
-        if (.not. f_is_default(Re_inv)) f_cpbw_KM = f_cpbw_KM - 4.d0*Re_inv*fV/fR
+        if (.not. f_is_default(Web)) f_cpbw_KM = f_cpbw_KM - 2._wp/(fR*Web)
+        if (.not. f_is_default(Re_inv)) f_cpbw_KM = f_cpbw_KM - 4._wp*Re_inv*fV/fR
 
     end function f_cpbw_KM
 
@@ -790,32 +791,32 @@ contains
         !!  @param fC Current sound speed
     function f_rddot_KM(fpbdot, fCp, fCpbw, fRho, fR, fV, fR0, fC)
         !$acc routine seq
-        real(kind(0d0)), intent(in) :: fpbdot, fCp, fCpbw
-        real(kind(0d0)), intent(in) :: fRho, fR, fV, fR0, fC
+        real(wp), intent(in) :: fpbdot, fCp, fCpbw
+        real(wp), intent(in) :: fRho, fR, fV, fR0, fC
 
-        real(kind(0d0)) :: tmp1, tmp2, cdot_star
-        real(kind(0d0)) :: f_rddot_KM
+        real(wp) :: tmp1, tmp2, cdot_star
+        real(wp) :: f_rddot_KM
 
         if (polytropic) then
-            cdot_star = -3d0*gam*Ca*((fR0/fR)**(3d0*gam))*fV/fR
+            cdot_star = -3._wp*gam*Ca*((fR0/fR)**(3._wp*gam))*fV/fR
             if (.not. f_is_default(Web)) cdot_star = cdot_star - &
-                                                     3d0*gam*(2d0/(Web*fR0))*((fR0/fR)**(3d0*gam))*fV/fR
+                                                     3._wp*gam*(2._wp/(Web*fR0))*((fR0/fR)**(3._wp*gam))*fV/fR
         else
             cdot_star = fpbdot
         end if
 
-        if (.not. f_is_default(Web)) cdot_star = cdot_star + (2d0/Web)*fV/(fR**2d0)
-        if (.not. f_is_default(Re_inv)) cdot_star = cdot_star + 4d0*Re_inv*((fV/fR)**2d0)
+        if (.not. f_is_default(Web)) cdot_star = cdot_star + (2._wp/Web)*fV/(fR**2._wp)
+        if (.not. f_is_default(Re_inv)) cdot_star = cdot_star + 4._wp*Re_inv*((fV/fR)**2._wp)
 
         tmp1 = fV/fC
-        tmp2 = 1.5d0*(fV**2d0)*(tmp1/3d0 - 1d0) + &
-               (1d0 + tmp1)*(fCpbw - fCp)/fRho + &
+        tmp2 = 1.5_wp*(fV**2._wp)*(tmp1/3._wp - 1._wp) + &
+               (1._wp + tmp1)*(fCpbw - fCp)/fRho + &
                cdot_star*fR/(fRho*fC)
 
         if (f_is_default(Re_inv)) then
-            f_rddot_KM = tmp2/(fR*(1d0 - tmp1))
+            f_rddot_KM = tmp2/(fR*(1._wp - tmp1))
         else
-            f_rddot_KM = tmp2/(fR*(1d0 - tmp1) + 4d0*Re_inv/(fRho*fC))
+            f_rddot_KM = tmp2/(fR*(1._wp - tmp1) + 4._wp*Re_inv/(fRho*fC))
         end if
 
     end function f_rddot_KM
@@ -825,17 +826,17 @@ contains
         !!  @param iR0 Current bubble size index
     subroutine s_bwproperty(pb, iR0)
         !$acc routine seq
-        real(kind(0.d0)), intent(in) :: pb
+        real(wp), intent(in) :: pb
         integer, intent(in) :: iR0
 
-        real(kind(0.d0)) :: x_vw
+        real(wp) :: x_vw
 
         ! mass fraction of vapor
-        chi_vw = 1.d0/(1.d0 + R_v/R_n*(pb/pv - 1.d0))
+        chi_vw = 1._wp/(1._wp + R_v/R_n*(pb/pv - 1._wp))
         ! mole fraction of vapor & thermal conductivity of gas mixture
         x_vw = M_n*chi_vw/(M_v + (M_n - M_v)*chi_vw)
-        k_mw = x_vw*k_v(iR0)/(x_vw + (1.d0 - x_vw)*phi_vn) &
-               + (1.d0 - x_vw)*k_n(iR0)/(x_vw*phi_nv + 1.d0 - x_vw)
+        k_mw = x_vw*k_v(iR0)/(x_vw + (1._wp - x_vw)*phi_vn) &
+               + (1._wp - x_vw)*k_n(iR0)/(x_vw*phi_nv + 1._wp - x_vw)
         ! gas mixture density
         rho_mw = pv/(chi_vw*R_v*Tw)
 
@@ -848,20 +849,20 @@ contains
         !!  @param iR0 Bubble size index
     function f_vflux(fR, fV, fmass_v, iR0)
         !$acc routine seq
-        real(kind(0.d0)), intent(in) :: fR
-        real(kind(0.d0)), intent(in) :: fV
-        real(kind(0.d0)), intent(in) :: fmass_v
+        real(wp), intent(in) :: fR
+        real(wp), intent(in) :: fV
+        real(wp), intent(in) :: fmass_v
         integer, intent(in) :: iR0
 
-        real(kind(0.d0)) :: chi_bar
-        real(kind(0.d0)) :: grad_chi
-        real(kind(0.d0)) :: f_vflux
+        real(wp) :: chi_bar
+        real(wp) :: grad_chi
+        real(wp) :: f_vflux
 
         if (thermal == 3) then !transfer
             ! constant transfer model
             chi_bar = fmass_v/(fmass_v + mass_n0(iR0))
             grad_chi = -Re_trans_c(iR0)*(chi_bar - chi_vw)
-            f_vflux = rho_mw*grad_chi/Pe_c/(1.d0 - chi_vw)/fR
+            f_vflux = rho_mw*grad_chi/Pe_c/(1._wp - chi_vw)/fR
         else
             ! polytropic
             f_vflux = pv*fV/(R_v*Tw)
@@ -879,25 +880,25 @@ contains
         !!  @param iR0 Bubble size index
     function f_bpres_dot(fvflux, fR, fV, fpb, fmass_v, iR0)
         !$acc routine seq
-        real(kind(0.d0)), intent(in) :: fvflux
-        real(kind(0.d0)), intent(in) :: fR
-        real(kind(0.d0)), intent(in) :: fV
-        real(kind(0.d0)), intent(in) :: fpb
-        real(kind(0.d0)), intent(in) :: fmass_v
+        real(wp), intent(in) :: fvflux
+        real(wp), intent(in) :: fR
+        real(wp), intent(in) :: fV
+        real(wp), intent(in) :: fpb
+        real(wp), intent(in) :: fmass_v
         integer, intent(in) :: iR0
 
-        real(kind(0.d0)) :: T_bar
-        real(kind(0.d0)) :: grad_T
-        real(kind(0.d0)) :: f_bpres_dot
+        real(wp) :: T_bar
+        real(wp) :: grad_T
+        real(wp) :: f_bpres_dot
 
         if (thermal == 3) then
             T_bar = Tw*(fpb/pb0(iR0))*(fR/R0(iR0))**3 &
                     *(mass_n0(iR0) + mass_v0(iR0))/(mass_n0(iR0) + fmass_v)
             grad_T = -Re_trans_T(iR0)*(T_bar - Tw)
-            f_bpres_dot = 3.d0*gamma_m*(-fV*fpb + fvflux*R_v*Tw &
-                                        + pb0(iR0)*k_mw*grad_T/Pe_T(iR0)/fR)/fR
+            f_bpres_dot = 3._wp*gamma_m*(-fV*fpb + fvflux*R_v*Tw &
+                                         + pb0(iR0)*k_mw*grad_T/Pe_T(iR0)/fR)/fR
         else
-            f_bpres_dot = -3.d0*gamma_m*fV/fR*(fpb - pv)
+            f_bpres_dot = -3._wp*gamma_m*fV/fR*(fpb - pv)
         end if
 
     end function f_bpres_dot
diff --git a/src/simulation/m_cbc.fpp b/src/simulation/m_cbc.fpp
index 2ab816965..d888a3f91 100644
--- a/src/simulation/m_cbc.fpp
+++ b/src/simulation/m_cbc.fpp
@@ -40,18 +40,18 @@ module m_cbc
     !! q_prim_vf in the coordinate direction normal to the domain boundary along
     !! which the CBC is applied.
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: q_prim_rsx_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: q_prim_rsy_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: q_prim_rsz_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: q_prim_rsx_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: q_prim_rsy_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: q_prim_rsz_vf
 
     type(scalar_field), allocatable, dimension(:) :: F_rs_vf, F_src_rs_vf !<
 
     !! Cell-average fluxes (src - source). These are directly determined from the
     !! cell-average primitive variables, q_prims_rs_vf, and not a Riemann solver.
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: F_rsx_vf, F_src_rsx_vf !<
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: F_rsy_vf, F_src_rsy_vf !<
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: F_rsz_vf, F_src_rsz_vf !<
+    real(wp), allocatable, dimension(:, :, :, :) :: F_rsx_vf, F_src_rsx_vf !<
+    real(wp), allocatable, dimension(:, :, :, :) :: F_rsy_vf, F_src_rsy_vf !<
+    real(wp), allocatable, dimension(:, :, :, :) :: F_rsz_vf, F_src_rsz_vf !<
 
     !! There is a CCE bug that is causing some subset of these variables to interfere
     !! with variables of the same name in m_riemann_solvers.fpp, and giving this versions
@@ -59,34 +59,34 @@ module m_cbc
     !! in `acc declare create` clauses don't have this problem, so we still need to
     !! isolate this bug.
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_rsx_vf_l, flux_src_rsx_vf_l !<
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_rsy_vf_l, flux_src_rsy_vf_l
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_rsz_vf_l, flux_src_rsz_vf_l
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_rsx_vf_l, flux_src_rsx_vf_l !<
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_rsy_vf_l, flux_src_rsy_vf_l
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_rsz_vf_l, flux_src_rsz_vf_l
 
-    real(kind(0d0)) :: c           !< Cell averaged speed of sound
-    real(kind(0d0)), dimension(2) :: Re          !< Cell averaged Reynolds numbers
+    real(wp) :: c           !< Cell averaged speed of sound
+    real(wp), dimension(2) :: Re          !< Cell averaged Reynolds numbers
     !$acc declare create(c, Re)
 
-    real(kind(0d0)) :: dpres_ds !< Spatial derivatives in s-dir of pressure
+    real(wp) :: dpres_ds !< Spatial derivatives in s-dir of pressure
     !$acc declare create(dpres_ds)
 
-    real(kind(0d0)), allocatable, dimension(:) :: ds !< Cell-width distribution in the s-direction
+    real(wp), allocatable, dimension(:) :: ds !< Cell-width distribution in the s-direction
 
     ! CBC Coefficients =========================================================
 
-    real(kind(0d0)), allocatable, dimension(:, :) :: fd_coef_x !< Finite diff. coefficients x-dir
-    real(kind(0d0)), allocatable, dimension(:, :) :: fd_coef_y !< Finite diff. coefficients y-dir
-    real(kind(0d0)), allocatable, dimension(:, :) :: fd_coef_z !< Finite diff. coefficients z-dir
+    real(wp), allocatable, dimension(:, :) :: fd_coef_x !< Finite diff. coefficients x-dir
+    real(wp), allocatable, dimension(:, :) :: fd_coef_y !< Finite diff. coefficients y-dir
+    real(wp), allocatable, dimension(:, :) :: fd_coef_z !< Finite diff. coefficients z-dir
 
     !! The first dimension identifies the location of a coefficient in the FD
     !! formula, while the last dimension denotes the location of the CBC.
 
     ! Bug with NVHPC when using nullified pointers in a declare create
-    !    real(kind(0d0)), pointer, dimension(:, :) :: fd_coef => null()
+    !    real(wp), pointer, dimension(:, :) :: fd_coef => null()
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: pi_coef_x !< Polynomial interpolant coefficients in x-dir
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: pi_coef_y !< Polynomial interpolant coefficients in y-dir
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: pi_coef_z !< Polynomial interpolant coefficients in z-dir
+    real(wp), allocatable, dimension(:, :, :) :: pi_coef_x !< Polynomial interpolant coefficients in x-dir
+    real(wp), allocatable, dimension(:, :, :) :: pi_coef_y !< Polynomial interpolant coefficients in y-dir
+    real(wp), allocatable, dimension(:, :, :) :: pi_coef_z !< Polynomial interpolant coefficients in z-dir
 
     !! The first dimension of the array identifies the polynomial, the
     !! second dimension identifies the position of its coefficients and the last
@@ -106,9 +106,9 @@ module m_cbc
     !! inflow velocities, pressure, density and void fraction as well as
     !! outflow velocities and pressure
 
-    real(kind(0d0)), allocatable, dimension(:) :: pres_in, pres_out, Del_in, Del_out
-    real(kind(0d0)), allocatable, dimension(:, :) :: vel_in, vel_out
-    real(kind(0d0)), allocatable, dimension(:, :) :: alpha_rho_in, alpha_in
+    real(wp), allocatable, dimension(:) :: pres_in, pres_out, Del_in, Del_out
+    real(wp), allocatable, dimension(:, :) :: vel_in, vel_out
+    real(wp), allocatable, dimension(:, :) :: alpha_rho_in, alpha_in
     !$acc declare create(pres_in, pres_out, Del_in, Del_out)
     !$acc declare create(vel_in, vel_out)
     !$acc declare create(alpha_rho_in, alpha_in)
@@ -448,7 +448,7 @@ contains
         integer, intent(in) :: cbc_dir_in, cbc_loc_in
 
         ! Cell-boundary locations in the s-direction
-        real(kind(0d0)), dimension(0:buff_size + 1) :: s_cb
+        real(wp), dimension(0:buff_size + 1) :: s_cb
 
         ! Generic loop iterator
         integer :: i
@@ -457,7 +457,7 @@ contains
         call s_associate_cbc_coefficients_pointers(cbc_dir_in, cbc_loc_in)
 
         ! Determining the cell-boundary locations in the s-direction
-        s_cb(0) = 0d0
+        s_cb(0) = 0._wp
 
         do i = 0, buff_size
             s_cb(i + 1) = s_cb(i) + ds(i)
@@ -468,8 +468,8 @@ contains
             if (cbc_dir_in == ${CBC_DIR}$) then
                 if (weno_order == 1) then
 
-                    fd_coef_${XYZ}$ (:, cbc_loc_in) = 0d0
-                    fd_coef_${XYZ}$ (0, cbc_loc_in) = -2d0/(ds(0) + ds(1))
+                    fd_coef_${XYZ}$ (:, cbc_loc_in) = 0._wp
+                    fd_coef_${XYZ}$ (0, cbc_loc_in) = -2._wp/(ds(0) + ds(1))
                     fd_coef_${XYZ}$ (1, cbc_loc_in) = -fd_coef_${XYZ}$ (0, cbc_loc_in)
 
                     ! ==================================================================
@@ -477,10 +477,10 @@ contains
                     ! Computing CBC2 Coefficients ======================================
                 elseif (weno_order == 3) then
 
-                    fd_coef_${XYZ}$ (:, cbc_loc_in) = 0d0
-                    fd_coef_${XYZ}$ (0, cbc_loc_in) = -6d0/(3d0*ds(0) + 2d0*ds(1) - ds(2))
-                    fd_coef_${XYZ}$ (1, cbc_loc_in) = -4d0*fd_coef_${XYZ}$ (0, cbc_loc_in)/3d0
-                    fd_coef_${XYZ}$ (2, cbc_loc_in) = fd_coef_${XYZ}$ (0, cbc_loc_in)/3d0
+                    fd_coef_${XYZ}$ (:, cbc_loc_in) = 0._wp
+                    fd_coef_${XYZ}$ (0, cbc_loc_in) = -6._wp/(3._wp*ds(0) + 2._wp*ds(1) - ds(2))
+                    fd_coef_${XYZ}$ (1, cbc_loc_in) = -4._wp*fd_coef_${XYZ}$ (0, cbc_loc_in)/3._wp
+                    fd_coef_${XYZ}$ (2, cbc_loc_in) = fd_coef_${XYZ}$ (0, cbc_loc_in)/3._wp
 
                     pi_coef_${XYZ}$ (0, 0, cbc_loc_in) = (s_cb(0) - s_cb(1))/(s_cb(0) - s_cb(2))
 
@@ -489,14 +489,14 @@ contains
                     ! Computing CBC4 Coefficients ======================================
                 else
 
-                    fd_coef_${XYZ}$ (:, cbc_loc_in) = 0d0
-                    fd_coef_${XYZ}$ (0, cbc_loc_in) = -50d0/(25d0*ds(0) + 2d0*ds(1) &
-                                                             - 1d1*ds(2) + 1d1*ds(3) &
-                                                             - 3d0*ds(4))
-                    fd_coef_${XYZ}$ (1, cbc_loc_in) = -48d0*fd_coef_${XYZ}$ (0, cbc_loc_in)/25d0
-                    fd_coef_${XYZ}$ (2, cbc_loc_in) = 36d0*fd_coef_${XYZ}$ (0, cbc_loc_in)/25d0
-                    fd_coef_${XYZ}$ (3, cbc_loc_in) = -16d0*fd_coef_${XYZ}$ (0, cbc_loc_in)/25d0
-                    fd_coef_${XYZ}$ (4, cbc_loc_in) = 3d0*fd_coef_${XYZ}$ (0, cbc_loc_in)/25d0
+                    fd_coef_${XYZ}$ (:, cbc_loc_in) = 0._wp
+                    fd_coef_${XYZ}$ (0, cbc_loc_in) = -50._wp/(25._wp*ds(0) + 2._wp*ds(1) &
+                                                               - 1e1_wp*ds(2) + 1e1_wp*ds(3) &
+                                                               - 3._wp*ds(4))
+                    fd_coef_${XYZ}$ (1, cbc_loc_in) = -48._wp*fd_coef_${XYZ}$ (0, cbc_loc_in)/25._wp
+                    fd_coef_${XYZ}$ (2, cbc_loc_in) = 36._wp*fd_coef_${XYZ}$ (0, cbc_loc_in)/25._wp
+                    fd_coef_${XYZ}$ (3, cbc_loc_in) = -16._wp*fd_coef_${XYZ}$ (0, cbc_loc_in)/25._wp
+                    fd_coef_${XYZ}$ (4, cbc_loc_in) = 3._wp*fd_coef_${XYZ}$ (0, cbc_loc_in)/25._wp
 
                     pi_coef_${XYZ}$ (0, 0, cbc_loc_in) = &
                         ((s_cb(0) - s_cb(1))*(s_cb(1) - s_cb(2))* &
@@ -640,37 +640,38 @@ contains
         ! First-order time derivatives of the partial densities, density,
         ! velocity, pressure, advection variables, and the specific heat
         ! ratio and liquid stiffness functions
-        real(kind(0d0)), dimension(num_fluids) :: dalpha_rho_dt
-        real(kind(0d0)) :: drho_dt
-        real(kind(0d0)), dimension(num_dims) :: dvel_dt
-        real(kind(0d0)) :: dpres_dt
-        real(kind(0d0)), dimension(num_fluids) :: dadv_dt
-        real(kind(0d0)) :: dgamma_dt
-        real(kind(0d0)) :: dpi_inf_dt
-        real(kind(0d0)) :: dqv_dt
-        real(kind(0d0)), dimension(contxe) :: alpha_rho, dalpha_rho_ds, mf
-        real(kind(0d0)), dimension(2) :: Re_cbc
-        real(kind(0d0)), dimension(num_dims) :: vel, dvel_ds
-        real(kind(0d0)), dimension(num_fluids) :: adv, dadv_ds
-        real(kind(0d0)), dimension(sys_size) :: L
-        real(kind(0d0)), dimension(3) :: lambda
-        real(kind(0d0)), dimension(num_species) :: Y_s
-
-        real(kind(0d0)) :: rho         !< Cell averaged density
-        real(kind(0d0)) :: pres        !< Cell averaged pressure
-        real(kind(0d0)) :: E           !< Cell averaged energy
-        real(kind(0d0)) :: H           !< Cell averaged enthalpy
-        real(kind(0d0)) :: gamma       !< Cell averaged specific heat ratio
-        real(kind(0d0)) :: pi_inf      !< Cell averaged liquid stiffness
-        real(kind(0d0)) :: qv          !< Cell averaged fluid reference energy
-        real(kind(0d0)) :: c
-        real(kind(0d0)) :: Ma
-
-        real(kind(0d0)) :: vel_K_sum, vel_dv_dt_sum
+
+        real(wp), dimension(num_fluids) :: dalpha_rho_dt
+        real(wp) :: drho_dt
+        real(wp), dimension(num_dims) :: dvel_dt
+        real(wp) :: dpres_dt
+        real(wp), dimension(num_fluids) :: dadv_dt
+        real(wp) :: dgamma_dt
+        real(wp) :: dpi_inf_dt
+        real(wp) :: dqv_dt
+        real(wp), dimension(contxe) :: alpha_rho, dalpha_rho_ds, mf
+        real(wp), dimension(2) :: Re_cbc
+        real(wp), dimension(num_dims) :: vel, dvel_ds
+        real(wp), dimension(num_fluids) :: adv, dadv_ds
+        real(wp), dimension(sys_size) :: L
+        real(wp), dimension(3) :: lambda
+        real(wp), dimension(num_species) :: Y_s
+
+        real(wp) :: rho         !< Cell averaged density
+        real(wp) :: pres        !< Cell averaged pressure
+        real(wp) :: E           !< Cell averaged energy
+        real(wp) :: H           !< Cell averaged enthalpy
+        real(wp) :: gamma       !< Cell averaged specific heat ratio
+        real(wp) :: pi_inf      !< Cell averaged liquid stiffness
+        real(wp) :: qv          !< Cell averaged fluid reference energy
+        real(wp) :: c
+        real(wp) :: Ma
+
+        real(wp) :: vel_K_sum, vel_dv_dt_sum
 
         integer :: i, j, k, r, q !< Generic loop iterators
 
-        real(kind(0d0)) :: blkmod1, blkmod2 !< Fluid bulk modulus for Wood mixture sound speed
+        real(wp) :: blkmod1, blkmod2 !< Fluid bulk modulus for Wood mixture sound speed
 
         ! Reshaping of inputted data and association of the FD and PI
         ! coefficients, or CBC coefficients, respectively, hinging on
@@ -788,10 +789,10 @@ contains
                             vel(i) = q_prim_rs${XYZ}$_vf(0, k, r, contxe + i)
                         end do
 
-                        vel_K_sum = 0d0
+                        vel_K_sum = 0._wp
                         !$acc loop seq
                         do i = 1, num_dims
-                            vel_K_sum = vel_K_sum + vel(i)**2d0
+                            vel_K_sum = vel_K_sum + vel(i)**2._wp
                         end do
 
                         pres = q_prim_rs${XYZ}$_vf(0, k, r, E_idx)
@@ -812,29 +813,29 @@ contains
                             mf(i) = alpha_rho(i)/rho
                         end do
 
-                        E = gamma*pres + pi_inf + 5d-1*rho*vel_K_sum
+                        E = gamma*pres + pi_inf + 5e-1_wp*rho*vel_K_sum
                         H = (E + pres)/rho
 
                         ! Compute mixture sound speed
-                        call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, H, adv, vel_K_sum, 0d0, c)
+                        call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, H, adv, vel_K_sum, 0._wp, c)
                         ! ============================================================
 
                         ! First-Order Spatial Derivatives of Primitive Variables =====
 
                         !$acc loop seq
                         do i = 1, contxe
-                            dalpha_rho_ds(i) = 0d0
+                            dalpha_rho_ds(i) = 0._wp
                         end do
 
                         !$acc loop seq
                         do i = 1, num_dims
-                            dvel_ds(i) = 0d0
+                            dvel_ds(i) = 0._wp
                         end do
 
-                        dpres_ds = 0d0
+                        dpres_ds = 0._wp
                         !$acc loop seq
                         do i = 1, advxe - E_idx
-                            dadv_ds(i) = 0d0
+                            dadv_ds(i) = 0._wp
                         end do
 
                         !$acc loop seq
@@ -882,7 +883,7 @@ contains
                             if (bc_${XYZ}$%grcbc_in) then
                                 !$acc loop seq
                                 do i = 2, momxb
-                                    L(2) = c**3d0*Ma*(alpha_rho(i - 1) - alpha_rho_in(i - 1, ${CBC_DIR}$))/Del_in(${CBC_DIR}$) - c*Ma*(pres - pres_in(${CBC_DIR}$))/Del_in(${CBC_DIR}$)
+                                    L(2) = c**3._wp*Ma*(alpha_rho(i - 1) - alpha_rho_in(i - 1, ${CBC_DIR}$))/Del_in(${CBC_DIR}$) - c*Ma*(pres - pres_in(${CBC_DIR}$))/Del_in(${CBC_DIR}$)
                                 end do
                                 if (n > 0) then
                                     L(momxb + 1) = c*Ma*(vel(dir_idx(2)) - vel_in(${CBC_DIR}$, dir_idx(2)))/Del_in(${CBC_DIR}$)
@@ -894,17 +895,17 @@ contains
                                 do i = E_idx, advxe - 1
                                     L(i) = c*Ma*(adv(i + 1 - E_idx) - alpha_in(i + 1 - E_idx, ${CBC_DIR}$))/Del_in(${CBC_DIR}$)
                                 end do
-                                L(advxe) = rho*c**2d0*(1d0 + Ma)*(vel(dir_idx(1)) + vel_in(${CBC_DIR}$, dir_idx(1))*sign(1, cbc_loc))/Del_in(${CBC_DIR}$) + c*(1d0 + Ma)*(pres - pres_in(${CBC_DIR}$))/Del_in(${CBC_DIR}$)
+                                L(advxe) = rho*c**2._wp*(1._wp + Ma)*(vel(dir_idx(1)) + vel_in(${CBC_DIR}$, dir_idx(1))*sign(1, cbc_loc))/Del_in(${CBC_DIR}$) + c*(1._wp + Ma)*(pres - pres_in(${CBC_DIR}$))/Del_in(${CBC_DIR}$)
                             end if
                         else if ((cbc_loc == -1 .and. bc${XYZ}$b == -8) .or. (cbc_loc == 1 .and. bc${XYZ}$e == -8)) then
                             call s_compute_nonreflecting_subsonic_outflow_L(lambda, L, rho, c, mf, dalpha_rho_ds, dpres_ds, dvel_ds, dadv_ds)
                             ! Add GRCBC for Subsonic Outflow (Pressure)
                             if (bc_${XYZ}$%grcbc_out) then
-                                L(advxe) = c*(1d0 - Ma)*(pres - pres_out(${CBC_DIR}$))/Del_out(${CBC_DIR}$)
+                                L(advxe) = c*(1._wp - Ma)*(pres - pres_out(${CBC_DIR}$))/Del_out(${CBC_DIR}$)
 
                                 ! Add GRCBC for Subsonic Outflow (Normal Velocity)
                                 if (bc_${XYZ}$%grcbc_vel_out) then
-                                    L(advxe) = L(advxe) + rho*c**2d0*(1d0 - Ma)*(vel(dir_idx(1)) + vel_out(${CBC_DIR}$, dir_idx(1))*sign(1, cbc_loc))/Del_out(${CBC_DIR}$)
+                                    L(advxe) = L(advxe) + rho*c**2._wp*(1._wp - Ma)*(vel(dir_idx(1)) + vel_out(${CBC_DIR}$, dir_idx(1))*sign(1, cbc_loc))/Del_out(${CBC_DIR}$)
                                 end if
                             end if
                         else if ((cbc_loc == -1 .and. bc${XYZ}$b == -9) .or. (cbc_loc == 1 .and. bc${XYZ}$e == -9)) then
@@ -919,10 +920,10 @@ contains
 
                         ! Be careful about the cylindrical coordinate!
                         if (cyl_coord .and. cbc_dir == 2 .and. cbc_loc == 1) then
-                            dpres_dt = -5d-1*(L(advxe) + L(1)) + rho*c*c*vel(dir_idx(1)) &
+                            dpres_dt = -5e-1_wp*(L(advxe) + L(1)) + rho*c*c*vel(dir_idx(1)) &
                                        /y_cc(n)
                         else
-                            dpres_dt = -5d-1*(L(advxe) + L(1))
+                            dpres_dt = -5e-1_wp*(L(advxe) + L(1))
                         end if
 
                         !$acc loop seq
@@ -934,12 +935,12 @@ contains
                         !$acc loop seq
                         do i = 1, num_dims
                             dvel_dt(dir_idx(i)) = dir_flg(dir_idx(i))* &
-                                                  (L(1) - L(advxe))/(2d0*rho*c) + &
-                                                  (dir_flg(dir_idx(i)) - 1d0)* &
+                                                  (L(1) - L(advxe))/(2._wp*rho*c) + &
+                                                  (dir_flg(dir_idx(i)) - 1._wp)* &
                                                   L(momxb + i - 1)
                         end do
 
-                        vel_dv_dt_sum = 0d0
+                        vel_dv_dt_sum = 0._wp
                         !$acc loop seq
                         do i = 1, num_dims
                             vel_dv_dt_sum = vel_dv_dt_sum + vel(i)*dvel_dt(i)
@@ -958,7 +959,7 @@ contains
                             end do
                         end if
 
-                        drho_dt = 0d0; dgamma_dt = 0d0; dpi_inf_dt = 0d0; dqv_dt = 0d0
+                        drho_dt = 0._wp; dgamma_dt = 0._wp; dpi_inf_dt = 0._wp; dqv_dt = 0._wp
 
                         if (model_eqns == 1) then
                             drho_dt = dalpha_rho_dt(1)
@@ -995,19 +996,19 @@ contains
                                                                         + dpi_inf_dt &
                                                                         + dqv_dt &
                                                                         + rho*vel_dv_dt_sum &
-                                                                        + 5d-1*drho_dt*vel_K_sum)
+                                                                        + 5e-1_wp*drho_dt*vel_K_sum)
 
                         if (riemann_solver == 1) then
                             !$acc loop seq
                             do i = advxb, advxe
-                                flux_rs${XYZ}$_vf_l(-1, k, r, i) = 0d0
+                                flux_rs${XYZ}$_vf_l(-1, k, r, i) = 0._wp
                             end do
 
                             !$acc loop seq
                             do i = advxb, advxe
                                 flux_src_rs${XYZ}$_vf_l(-1, k, r, i) = &
-                                    1d0/max(abs(vel(dir_idx(1))), sgm_eps) &
-                                    *sign(1d0, vel(dir_idx(1))) &
+                                    1._wp/max(abs(vel(dir_idx(1))), sgm_eps) &
+                                    *sign(1._wp, vel(dir_idx(1))) &
                                     *(flux_rs${XYZ}$_vf_l(0, k, r, i) &
                                       + vel(dir_idx(1)) &
                                       *flux_src_rs${XYZ}$_vf_l(0, k, r, i) &
@@ -1077,13 +1078,13 @@ contains
 
         if (cbc_dir == 1) then
             is1%beg = 0; is1%end = buff_size; is2 = iy; is3 = iz
-            dir_idx = (/1, 2, 3/); dir_flg = (/1d0, 0d0, 0d0/)
+            dir_idx = (/1, 2, 3/); dir_flg = (/1._wp, 0._wp, 0._wp/)
         elseif (cbc_dir == 2) then
             is1%beg = 0; is1%end = buff_size; is2 = ix; is3 = iz
-            dir_idx = (/2, 1, 3/); dir_flg = (/0d0, 1d0, 0d0/)
+            dir_idx = (/2, 1, 3/); dir_flg = (/0._wp, 1._wp, 0._wp/)
         else
             is1%beg = 0; is1%end = buff_size; is2 = iy; is3 = ix
-            dir_idx = (/3, 1, 2/); dir_flg = (/0d0, 0d0, 1d0/)
+            dir_idx = (/3, 1, 2/); dir_flg = (/0._wp, 0._wp, 1._wp/)
         end if
 
         dj = max(0, cbc_loc)
@@ -1111,7 +1112,7 @@ contains
                     do j = 0, buff_size
                         q_prim_rsx_vf(j, k, r, momxb) = &
                             q_prim_vf(momxb)%sf(dj*(m - 2*j) + j, k, r)* &
-                            sign(1d0, -real(cbc_loc, kind(0d0)))
+                            sign(1._wp, -1._wp*cbc_loc)
                     end do
                 end do
             end do
@@ -1123,7 +1124,7 @@ contains
                         do j = -1, buff_size
                             flux_rsx_vf_l(j, k, r, i) = &
                                 flux_vf(i)%sf(dj*((m - 1) - 2*j) + j, k, r)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1158,7 +1159,7 @@ contains
                         do j = -1, buff_size
                             flux_src_rsx_vf_l(j, k, r, advxb) = &
                                 flux_src_vf(advxb)%sf(dj*((m - 1) - 2*j) + j, k, r)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1187,7 +1188,7 @@ contains
                     do j = 0, buff_size
                         q_prim_rsy_vf(j, k, r, momxb + 1) = &
                             q_prim_vf(momxb + 1)%sf(k, dj*(n - 2*j) + j, r)* &
-                            sign(1d0, -real(cbc_loc, kind(0d0)))
+                            sign(1._wp, -1._wp*cbc_loc)
                     end do
                 end do
             end do
@@ -1199,7 +1200,7 @@ contains
                         do j = -1, buff_size
                             flux_rsy_vf_l(j, k, r, i) = &
                                 flux_vf(i)%sf(k, dj*((n - 1) - 2*j) + j, r)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1234,7 +1235,7 @@ contains
                         do j = -1, buff_size
                             flux_src_rsy_vf_l(j, k, r, advxb) = &
                                 flux_src_vf(advxb)%sf(k, dj*((n - 1) - 2*j) + j, r)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1263,7 +1264,7 @@ contains
                     do j = 0, buff_size
                         q_prim_rsz_vf(j, k, r, momxe) = &
                             q_prim_vf(momxe)%sf(r, k, dj*(p - 2*j) + j)* &
-                            sign(1d0, -real(cbc_loc, kind(0d0)))
+                            sign(1._wp, -1._wp*cbc_loc)
                     end do
                 end do
             end do
@@ -1275,7 +1276,7 @@ contains
                         do j = -1, buff_size
                             flux_rsz_vf_l(j, k, r, i) = &
                                 flux_vf(i)%sf(r, k, dj*((p - 1) - 2*j) + j)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1310,7 +1311,7 @@ contains
                         do j = -1, buff_size
                             flux_src_rsz_vf_l(j, k, r, advxb) = &
                                 flux_src_vf(advxb)%sf(r, k, dj*((p - 1) - 2*j) + j)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1360,7 +1361,7 @@ contains
                         do j = -1, buff_size
                             flux_vf(i)%sf(dj*((m - 1) - 2*j) + j, k, r) = &
                                 flux_rsx_vf_l(j, k, r, i)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1394,7 +1395,7 @@ contains
                         do j = -1, buff_size
                             flux_src_vf(advxb)%sf(dj*((m - 1) - 2*j) + j, k, r) = &
                                 flux_src_rsx_vf_l(j, k, r, advxb)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1411,7 +1412,7 @@ contains
                         do j = -1, buff_size
                             flux_vf(i)%sf(k, dj*((n - 1) - 2*j) + j, r) = &
                                 flux_rsy_vf_l(j, k, r, i)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1446,7 +1447,7 @@ contains
                         do j = -1, buff_size
                             flux_src_vf(advxb)%sf(k, dj*((n - 1) - 2*j) + j, r) = &
                                 flux_src_rsy_vf_l(j, k, r, advxb)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1464,7 +1465,7 @@ contains
                         do j = -1, buff_size
                             flux_vf(i)%sf(r, k, dj*((p - 1) - 2*j) + j) = &
                                 flux_rsz_vf_l(j, k, r, i)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
@@ -1499,7 +1500,7 @@ contains
                         do j = -1, buff_size
                             flux_src_vf(advxb)%sf(r, k, dj*((p - 1) - 2*j) + j) = &
                                 flux_src_rsz_vf_l(j, k, r, advxb)* &
-                                sign(1d0, -real(cbc_loc, kind(0d0)))
+                                sign(1._wp, -1._wp*cbc_loc)
                         end do
                     end do
                 end do
diff --git a/src/simulation/m_checker.fpp b/src/simulation/m_checker.fpp
index d19a85f07..933f4e995 100644
--- a/src/simulation/m_checker.fpp
+++ b/src/simulation/m_checker.fpp
@@ -39,6 +39,7 @@ contains
         call s_check_inputs_body_forces
         call s_check_inputs_misc
         call s_check_inputs_grcbc
+        call s_check_inputs_geometry_precision
 
     end subroutine s_check_inputs
 
@@ -51,6 +52,7 @@ contains
 #ifndef MFC_cuTENSOR
         @:PROHIBIT(cu_tensor, "MFC was not built with the NVIDIA cuTENSOR library")
 #endif
+
     end subroutine s_check_inputs_compilers
 
     !> Checks constraints on WENO scheme parameters
@@ -66,13 +68,15 @@ contains
             "For 3D simulation, p must be greater than or equal to (num_stcls_min*weno_order - 1), whose value is "//trim(numStr))
         @:PROHIBIT(weno_order /= 1 .and. f_is_default(weno_eps), &
             "weno_order != 1, but weno_eps is not set. A typical value of weno_eps is 1e-6")
-        @:PROHIBIT(weno_eps <= 0d0, "weno_eps must be positive. A typical value of weno_eps is 1e-6")
-        @:PROHIBIT(wenoz .and. weno_order == 7 .and. f_is_default(wenoz_q), &
+
+        @:PROHIBIT(weno_eps <= 0._wp, "weno_eps must be positive. A typical value of weno_eps is 1e-6")
+        @:PROHIBIT(wenoz .and. weno_order == real(7, wp) .and. f_is_default(real(wenoz_q, wp)), &
             "wenoz is used at 7th order, but wenoz_q is not set. It should be either 2, 3, or 4")
-        @:PROHIBIT(wenoz .and. weno_order == 7 .and. .not. (f_approx_equal(wenoz_q, 2d0) .or. f_approx_equal(wenoz_q, 3d0) .or. f_approx_equal(wenoz_q, 4d0)), &
+        @:PROHIBIT(wenoz .and. weno_order == real(7, wp) .and. .not. (f_approx_equal(real(wenoz_q, wp), real(2, wp)) .or. &
+            f_approx_equal(real(wenoz_q, wp), real(3, wp)) .or. f_approx_equal(real(wenoz_q, wp), real(4, wp))), &
             "wenoz_q must be either 2, 3, or 4")
         @:PROHIBIT(teno .and. f_is_default(teno_CT), "teno is used, but teno_CT is not set. A typical value of teno_CT is 1e-6")
-        @:PROHIBIT(teno .and. teno_CT <= 0d0, "teno_CT must be positive. A typical value of teno_CT is 1e-6")
+        @:PROHIBIT(teno .and. teno_CT <= 0._wp, "teno_CT must be positive. A typical value of teno_CT is 1e-6")
         @:PROHIBIT(count([mapped_weno, wenoz, teno]) >= 2, "Only one of mapped_weno, wenoz, or teno can be set to true")
         @:PROHIBIT(weno_order == 1 .and. mapped_weno)
         @:PROHIBIT(weno_order == 1 .and. wenoz)
@@ -95,6 +99,14 @@ contains
         @:PROHIBIT(low_Mach /= 0 .and. model_eqns /= 2, "low_Mach = 1 or 2 requires model_eqns = 2")
     end subroutine s_check_inputs_riemann_solver
 
+    !> Checks constraints on geometry and precision
+    subroutine s_check_inputs_geometry_precision
+        ! Prevent spherical geometry in single precision
+#ifdef MFC_SINGLE_PRECISION
+        @:PROHIBIT(.not. (cyl_coord .neqv. .true. .or. (cyl_coord .and. p == 0)), "Fully 3D cylindrical grid (geometry = 3) is not supported in single precision.")
+#endif
+    end subroutine s_check_inputs_geometry_precision
+
     !> Checks constraints on time stepping parameters
     subroutine s_check_inputs_time_stepping
         if (.not. cfl_dt) then
@@ -200,7 +212,7 @@ contains
                 "acoustic("//trim(jStr)//")%dipole is not supported for support >= 5 (non-planar supports)")
             @:PROHIBIT(acoustic(j)%support < 5 .and. f_is_default(acoustic(j)%dir), &
                 "acoustic("//trim(jStr)//")%dir must be specified for support < 5 (planer support)")
-            @:PROHIBIT(acoustic(j)%support == 1 .and. f_approx_equal(acoustic(j)%dir, 0d0), &
+            @:PROHIBIT(acoustic(j)%support == 1 .and. f_approx_equal(acoustic(j)%dir, 0._wp), &
                 "acoustic("//trim(jStr)//")dir must be non-zero for support = 1")
             @:PROHIBIT(acoustic(j)%pulse == 2 .and. f_is_default(acoustic(j)%delay), &
                 "acoustic("//trim(jStr)//")%delay must be specified for pulse = 2 (Gaussian)")
@@ -209,20 +221,20 @@ contains
 
             @:PROHIBIT((acoustic(j)%support == 2 .or. acoustic(j)%support == 3) .and. f_is_default(acoustic(j)%length), &
                 "acoustic("//trim(jStr)//")%length must be specified for support = 2 or 3")
-            @:PROHIBIT((acoustic(j)%support == 2 .or. acoustic(j)%support == 3) .and. acoustic(j)%length <= 0d0, &
+            @:PROHIBIT((acoustic(j)%support == 2 .or. acoustic(j)%support == 3) .and. acoustic(j)%length <= 0._wp, &
                 "acoustic("//trim(jStr)//")%length must be positive for support = 2 or 3")
             @:PROHIBIT(acoustic(j)%support == 3 .and. f_is_default(acoustic(j)%height), &
                 "acoustic("//trim(jStr)//")%height must be specified for support = 3")
-            @:PROHIBIT(acoustic(j)%support == 3 .and. acoustic(j)%height <= 0d0, &
+            @:PROHIBIT(acoustic(j)%support == 3 .and. acoustic(j)%height <= 0._wp, &
                 "acoustic("//trim(jStr)//")%height must be positive for support = 3")
 
             @:PROHIBIT(acoustic(j)%support >= 5 .and. f_is_default(acoustic(j)%foc_length), &
                 "acoustic("//trim(jStr)//")%foc_length must be specified for support >= 5 (non-planar supports)")
-            @:PROHIBIT(acoustic(j)%support >= 5 .and. acoustic(j)%foc_length <= 0d0, &
+            @:PROHIBIT(acoustic(j)%support >= 5 .and. acoustic(j)%foc_length <= 0._wp, &
                 "acoustic("//trim(jStr)//")%foc_length must be positive for support >= 5 (non-planar supports)")
             @:PROHIBIT(acoustic(j)%support >= 5 .and. f_is_default(acoustic(j)%aperture), &
                 "acoustic("//trim(jStr)//")%aperture must be specified for support >= 5 (non-planar supports)")
-            @:PROHIBIT(acoustic(j)%support >= 5 .and. acoustic(j)%aperture <= 0d0, &
+            @:PROHIBIT(acoustic(j)%support >= 5 .and. acoustic(j)%aperture <= 0._wp, &
                 "acoustic("//trim(jStr)//")%aperture must be positive for support >= 5 (non-planar supports)")
 
             @:PROHIBIT(any(acoustic(j)%support == (/9, 10, 11/)) .and. acoustic(j)%num_elements == dflt_int, &
@@ -235,11 +247,11 @@ contains
                 "acoustic("//trim(jStr)//")%element_on must be less than or equal to num_elements for support = 9, 10, or 11 (transducer array)")
             @:PROHIBIT(any(acoustic(j)%support == (/9, 10/)) .and. f_is_default(acoustic(j)%element_spacing_angle), &
                 "acoustic("//trim(jStr)//")%element_spacing_angle must be specified for support = 9 or 10 (2D transducer array)")
-            @:PROHIBIT(any(acoustic(j)%support == (/9, 10/)) .and. acoustic(j)%element_spacing_angle < 0d0, &
+            @:PROHIBIT(any(acoustic(j)%support == (/9, 10/)) .and. acoustic(j)%element_spacing_angle < 0._wp, &
                 "acoustic("//trim(jStr)//")%element_spacing_angle must be non-negative for support = 9 or 10 (2D transducer array)")
             @:PROHIBIT(acoustic(j)%support == 11 .and. f_is_default(acoustic(j)%element_polygon_ratio), &
                 "acoustic("//trim(jStr)//")%element_polygon_ratio must be specified for support = 11 (3D transducer array)")
-            @:PROHIBIT(acoustic(j)%support == 11 .and. acoustic(j)%element_polygon_ratio <= 0d0, &
+            @:PROHIBIT(acoustic(j)%support == 11 .and. acoustic(j)%element_polygon_ratio <= 0._wp, &
                 "acoustic("//trim(jStr)//")%element_polygon_ratio must be positive for support = 11 (3D transducer array)")
         end do
 
@@ -282,7 +294,7 @@ contains
         do i = 1, num_fluids
             do j = 1, 2
                 call s_int_to_str(j, jStr)
-                @:PROHIBIT((.not. f_is_default(fluid_pp(i)%Re(j))) .and. fluid_pp(i)%Re(j) <= 0d0, &
+                @:PROHIBIT((.not. f_is_default(fluid_pp(i)%Re(j))) .and. fluid_pp(i)%Re(j) <= 0._wp, &
                     "fluid_pp("//trim(iStr)//")%"// "Re("//trim(jStr)//") must be positive.")
                 @:PROHIBIT(model_eqns == 1 .and. (.not. f_is_default(fluid_pp(i)%Re(j))), &
                     "model_eqns = 1 does not support fluid_pp("//trim(iStr)//")%"// "Re("//trim(jStr)//")")
diff --git a/src/simulation/m_chemistry.fpp b/src/simulation/m_chemistry.fpp
index 27e2923e3..d4c468420 100644
--- a/src/simulation/m_chemistry.fpp
+++ b/src/simulation/m_chemistry.fpp
@@ -39,7 +39,7 @@ contains
 
         !$acc kernels
         do i = 1, num_dims
-            grads(i)%sf(:, :, :) = 0.0d0
+            grads(i)%sf(:, :, :) = 0.0_wp
         end do
         !$acc end kernels
 
@@ -56,10 +56,11 @@ contains
         type(scalar_field), dimension(sys_size), intent(INOUT) :: rhs_vf, q_cons_qp, q_prim_qp
         integer :: x, y, z
         integer :: eqn
-        real(kind(0d0)) :: T
-        real(kind(0d0)) :: rho, omega_m
-        real(kind(0d0)), dimension(num_species) :: Ys
-        real(kind(0d0)), dimension(num_species) :: omega
+
+        real(wp) :: T
+        real(wp) :: rho, omega_m
+        real(wp), dimension(num_species) :: Ys
+        real(wp), dimension(num_species) :: omega
 
         if (chemistry) then
             !$acc parallel loop collapse(3) gang vector default(present) &
diff --git a/src/simulation/m_compute_cbc.fpp b/src/simulation/m_compute_cbc.fpp
index 6a18c1eb4..f7ef81c81 100644
--- a/src/simulation/m_compute_cbc.fpp
+++ b/src/simulation/m_compute_cbc.fpp
@@ -33,20 +33,20 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i
 
         L(1) = lambda(1)*(dpres_ds - rho*c*dvel_ds(dir_idx(1)))
 
         do i = 2, advxe
-            L(i) = 0d0
+            L(i) = 0._wp
         end do
 
         L(advxe) = L(1)
@@ -63,35 +63,35 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i !< Generic loop iterator
 
-        L(1) = (5d-1 - 5d-1*sign(1d0, lambda(1)))*lambda(1) &
+        L(1) = (5e-1_wp - 5e-1_wp*sign(1._wp, lambda(1)))*lambda(1) &
                *(dpres_ds - rho*c*dvel_ds(dir_idx(1)))
 
         do i = 2, momxb
-            L(i) = (5d-1 - 5d-1*sign(1d0, lambda(2)))*lambda(2) &
+            L(i) = (5e-1_wp - 5e-1_wp*sign(1._wp, lambda(2)))*lambda(2) &
                    *(c*c*dalpha_rho_ds(i - 1) - mf(i - 1)*dpres_ds)
         end do
 
         do i = momxb + 1, momxe
-            L(i) = (5d-1 - 5d-1*sign(1d0, lambda(2)))*lambda(2) &
+            L(i) = (5e-1_wp - 5e-1_wp*sign(1._wp, lambda(2)))*lambda(2) &
                    *(dvel_ds(dir_idx(i - contxe)))
         end do
 
         do i = E_idx, advxe - 1
-            L(i) = (5d-1 - 5d-1*sign(1d0, lambda(2)))*lambda(2) &
+            L(i) = (5e-1_wp - 5e-1_wp*sign(1._wp, lambda(2)))*lambda(2) &
                    *(dadv_ds(i - momxe))
         end do
 
-        L(advxe) = (5d-1 - 5d-1*sign(1d0, lambda(3)))*lambda(3) &
+        L(advxe) = (5e-1_wp - 5e-1_wp*sign(1._wp, lambda(3)))*lambda(3) &
                    *(dpres_ds + rho*c*dvel_ds(dir_idx(1)))
 
     end subroutine s_compute_nonreflecting_subsonic_buffer_L
@@ -105,20 +105,20 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i
 
         L(1) = lambda(1)*(dpres_ds - rho*c*dvel_ds(dir_idx(1)))
 
         do i = 2, advxe
-            L(i) = 0d0
+            L(i) = 0._wp
         end do
 
     end subroutine s_compute_nonreflecting_subsonic_inflow_L
@@ -133,13 +133,13 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i !> Generic loop iterator
 
@@ -158,7 +158,7 @@ contains
         end do
 
         ! bubble index
-        L(advxe) = 0d0
+        L(advxe) = 0._wp
 
     end subroutine s_compute_nonreflecting_subsonic_outflow_L
 
@@ -175,13 +175,13 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i !> Generic loop iterator
 
@@ -199,7 +199,7 @@ contains
             L(i) = lambda(2)*(dadv_ds(i - momxe))
         end do
 
-        L(advxe) = L(1) + 2d0*rho*c*lambda(2)*dvel_ds(dir_idx(1))
+        L(advxe) = L(1) + 2._wp*rho*c*lambda(2)*dvel_ds(dir_idx(1))
 
     end subroutine s_compute_force_free_subsonic_outflow_L
 
@@ -213,13 +213,13 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i !> Generic loop iterator
 
@@ -252,17 +252,17 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
         integer :: i
 
         do i = 1, advxe
-            L(i) = 0d0
+            L(i) = 0._wp
         end do
 
     end subroutine s_compute_supersonic_inflow_L
@@ -277,13 +277,13 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(3), intent(in) :: lambda
-        real(kind(0d0)), dimension(sys_size), intent(inout) :: L
-        real(kind(0d0)), intent(in) :: rho, c
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
-        real(kind(0d0)), intent(in) :: dpres_ds
-        real(kind(0d0)), dimension(num_dims), intent(in) :: dvel_ds
-        real(kind(0d0)), dimension(num_fluids), intent(in) :: dadv_ds
+        real(wp), dimension(3), intent(in) :: lambda
+        real(wp), dimension(sys_size), intent(inout) :: L
+        real(wp), intent(in) :: rho, c
+        real(wp), dimension(num_fluids), intent(in) :: mf, dalpha_rho_ds
+        real(wp), intent(in) :: dpres_ds
+        real(wp), dimension(num_dims), intent(in) :: dvel_ds
+        real(wp), dimension(num_fluids), intent(in) :: dadv_ds
 
         integer :: i !< Generic loop iterator
 
diff --git a/src/simulation/m_data_output.fpp b/src/simulation/m_data_output.fpp
index f69418f7e..2c74e757a 100644
--- a/src/simulation/m_data_output.fpp
+++ b/src/simulation/m_data_output.fpp
@@ -48,24 +48,24 @@ module m_data_output
               s_close_probe_files, &
               s_finalize_data_output_module
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: icfl_sf  !< ICFL stability criterion
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: vcfl_sf  !< VCFL stability criterion
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: ccfl_sf  !< CCFL stability criterion
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: Rc_sf  !< Rc stability criterion
+    real(wp), allocatable, dimension(:, :, :) :: icfl_sf  !< ICFL stability criterion
+    real(wp), allocatable, dimension(:, :, :) :: vcfl_sf  !< VCFL stability criterion
+    real(wp), allocatable, dimension(:, :, :) :: ccfl_sf  !< CCFL stability criterion
+    real(wp), allocatable, dimension(:, :, :) :: Rc_sf  !< Rc stability criterion
     !$acc declare create(icfl_sf, vcfl_sf, ccfl_sf, Rc_sf)
 
-    real(kind(0d0)) :: icfl_max_loc, icfl_max_glb !< ICFL stability extrema on local and global grids
-    real(kind(0d0)) :: vcfl_max_loc, vcfl_max_glb !< VCFL stability extrema on local and global grids
-    real(kind(0d0)) :: ccfl_max_loc, ccfl_max_glb !< CCFL stability extrema on local and global grids
-    real(kind(0d0)) :: Rc_min_loc, Rc_min_glb !< Rc   stability extrema on local and global grids
+    real(wp) :: icfl_max_loc, icfl_max_glb !< ICFL stability extrema on local and global grids
+    real(wp) :: vcfl_max_loc, vcfl_max_glb !< VCFL stability extrema on local and global grids
+    real(wp) :: ccfl_max_loc, ccfl_max_glb !< CCFL stability extrema on local and global grids
+    real(wp) :: Rc_min_loc, Rc_min_glb !< Rc   stability extrema on local and global grids
     !$acc declare create(icfl_max_loc, icfl_max_glb, vcfl_max_loc, vcfl_max_glb, ccfl_max_loc, ccfl_max_glb, Rc_min_loc, Rc_min_glb)
 
     !> @name ICFL, VCFL, CCFL and Rc stability criteria extrema over all the time-steps
     !> @{
-    real(kind(0d0)) :: icfl_max !< ICFL criterion maximum
-    real(kind(0d0)) :: vcfl_max !< VCFL criterion maximum
-    real(kind(0d0)) :: ccfl_max !< CCFL criterion maximum
-    real(kind(0d0)) :: Rc_min !< Rc criterion maximum
+    real(wp) :: icfl_max !< ICFL criterion maximum
+    real(wp) :: vcfl_max !< VCFL criterion maximum
+    real(wp) :: ccfl_max !< CCFL criterion maximum
+    real(wp) :: Rc_min !< Rc criterion maximum
     !> @}
 
 contains
@@ -215,16 +215,16 @@ contains
         type(scalar_field), dimension(sys_size), intent(IN) :: q_prim_vf
         integer, intent(IN) :: t_step
 
-        real(kind(0d0)) :: rho        !< Cell-avg. density
-        real(kind(0d0)), dimension(num_dims) :: vel        !< Cell-avg. velocity
-        real(kind(0d0)) :: vel_sum    !< Cell-avg. velocity sum
-        real(kind(0d0)) :: pres       !< Cell-avg. pressure
-        real(kind(0d0)), dimension(num_fluids) :: alpha      !< Cell-avg. volume fraction
-        real(kind(0d0)) :: gamma      !< Cell-avg. sp. heat ratio
-        real(kind(0d0)) :: pi_inf     !< Cell-avg. liquid stiffness function
-        real(kind(0d0)) :: c          !< Cell-avg. sound speed
-        real(kind(0d0)) :: H          !< Cell-avg. enthalpy
-        real(kind(0d0)), dimension(2) :: Re         !< Cell-avg. Reynolds numbers
+        real(wp) :: rho        !< Cell-avg. density
+        real(wp), dimension(num_dims) :: vel        !< Cell-avg. velocity
+        real(wp) :: vel_sum    !< Cell-avg. velocity sum
+        real(wp) :: pres       !< Cell-avg. pressure
+        real(wp), dimension(num_fluids) :: alpha      !< Cell-avg. volume fraction
+        real(wp) :: gamma      !< Cell-avg. sp. heat ratio
+        real(wp) :: pi_inf     !< Cell-avg. liquid stiffness function
+        real(wp) :: c          !< Cell-avg. sound speed
+        real(wp) :: H          !< Cell-avg. enthalpy
+        real(wp), dimension(2) :: Re         !< Cell-avg. Reynolds numbers
         integer :: j, k, l
 
         ! Computing Stability Criteria at Current Time-step ================
@@ -233,7 +233,8 @@ contains
             do k = 0, n
                 do j = 0, m
                     call s_compute_enthalpy(q_prim_vf, pres, rho, gamma, pi_inf, Re, H, alpha, vel, vel_sum, j, k, l)
-                    call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, H, alpha, vel_sum, 0d0, c)
+
+                    call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, H, alpha, vel_sum, 0._wp, c)
 
                     if (viscous) then
                         call s_compute_stability_from_dt(vel, c, rho, Re, j, k, l, icfl_sf, vcfl_sf, Rc_sf)
@@ -312,7 +313,7 @@ contains
 
             if (icfl_max_glb /= icfl_max_glb) then
                 call s_mpi_abort('ICFL is NaN. Exiting ...')
-            elseif (icfl_max_glb > 1d0) then
+            elseif (icfl_max_glb > 1._wp) then
                 print *, 'icfl', icfl_max_glb
                 call s_mpi_abort('ICFL is greater than 1.0. Exiting ...')
             end if
@@ -320,7 +321,7 @@ contains
             if (viscous) then
                 if (vcfl_max_glb /= vcfl_max_glb) then
                     call s_mpi_abort('VCFL is NaN. Exiting ...')
-                elseif (vcfl_max_glb > 1d0) then
+                elseif (vcfl_max_glb > 1._wp) then
                     print *, 'vcfl', vcfl_max_glb
                     call s_mpi_abort('VCFL is greater than 1.0. Exiting ...')
                 end if
@@ -355,7 +356,7 @@ contains
 
         integer :: i, j, k, l, r
 
-        real(kind(0d0)) :: gamma, lit_gamma, pi_inf, qv !< Temporary EOS params
+        real(wp) :: gamma, lit_gamma, pi_inf, qv !< Temporary EOS params
 
         ! Creating or overwriting the time-step root directory
         write (t_step_dir, '(A,I0,A,I0)') trim(case_dir)//'/p_all'
@@ -452,7 +453,7 @@ contains
         end if
 
         gamma = fluid_pp(1)%gamma
-        lit_gamma = 1d0/fluid_pp(1)%gamma + 1d0
+        lit_gamma = 1._wp/fluid_pp(1)%gamma + 1._wp
         pi_inf = fluid_pp(1)%pi_inf
         qv = fluid_pp(1)%qv
 
@@ -475,9 +476,9 @@ contains
             do i = 1, sys_size
                 !$acc update host(q_prim_vf(i)%sf(:,:,:))
             end do
-            ! q_prim_vf(bubxb) stores the value of nb needed in riemann solvers, so replace with true primitive value (=1d0)
+            ! q_prim_vf(bubxb) stores the value of nb needed in riemann solvers, so replace with true primitive value (=1._wp)
             if (qbmm) then
-                q_prim_vf(bubxb)%sf = 1d0
+                q_prim_vf(bubxb)%sf = 1._wp
             end if
         end if
 
@@ -770,8 +771,8 @@ contains
             m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
             n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
             p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-            WP_MOK = int(8d0, MPI_OFFSET_KIND)
-            MOK = int(1d0, MPI_OFFSET_KIND)
+            WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+            MOK = int(1._wp, MPI_OFFSET_KIND)
             str_MOK = int(name_len, MPI_OFFSET_KIND)
             NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -781,7 +782,7 @@ contains
                     var_MOK = int(i, MPI_OFFSET_KIND)
 
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
                 !Write pb and mv for non-polytropic qbmm
                 if (qbmm .and. .not. polytropic) then
@@ -789,7 +790,7 @@ contains
                         var_MOK = int(i, MPI_OFFSET_KIND)
 
                         call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                                MPI_DOUBLE_PRECISION, status, ierr)
+                                                mpi_p, status, ierr)
                     end do
                 end if
             else
@@ -797,7 +798,7 @@ contains
                     var_MOK = int(i, MPI_OFFSET_KIND)
 
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
             end if
 
@@ -827,8 +828,8 @@ contains
             m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
             n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
             p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-            WP_MOK = int(8d0, MPI_OFFSET_KIND)
-            MOK = int(1d0, MPI_OFFSET_KIND)
+            WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+            MOK = int(1._wp, MPI_OFFSET_KIND)
             str_MOK = int(name_len, MPI_OFFSET_KIND)
             NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -840,10 +841,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
                 !Write pb and mv for non-polytropic qbmm
                 if (qbmm .and. .not. polytropic) then
@@ -853,10 +854,10 @@ contains
                         ! Initial displacement to skip at beginning of file
                         disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                                MPI_DOUBLE_PRECISION, status, ierr)
+                                                mpi_p, status, ierr)
                     end do
                 end if
             else
@@ -866,10 +867,10 @@ contains
                     ! Initial displacement to skip at beginning of file
                     disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                    call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                    call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                            'native', mpi_info_int, ierr)
                     call MPI_FILE_WRITE_ALL(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                            MPI_DOUBLE_PRECISION, status, ierr)
+                                            mpi_p, status, ierr)
                 end do
             end if
 
@@ -888,89 +889,90 @@ contains
 
         integer, intent(in) :: t_step
         type(scalar_field), dimension(sys_size), intent(in) :: q_cons_vf
-        real(kind(0d0)), dimension(0:m, 0:n, 0:p), intent(in) :: accel_mag
+        real(wp), dimension(0:m, 0:n, 0:p), intent(in) :: accel_mag
 
-        real(kind(0d0)), dimension(-1:m) :: distx
-        real(kind(0d0)), dimension(-1:n) :: disty
-        real(kind(0d0)), dimension(-1:p) :: distz
+        real(wp), dimension(-1:m) :: distx
+        real(wp), dimension(-1:n) :: disty
+        real(wp), dimension(-1:p) :: distz
 
         ! The cell-averaged partial densities, density, velocity, pressure,
         ! volume fractions, specific heat ratio function, liquid stiffness
         ! function, and sound speed.
-        real(kind(0d0)) :: lit_gamma, nbub
-        real(kind(0d0)) :: rho
-        real(kind(0d0)), dimension(num_dims) :: vel
-        real(kind(0d0)) :: pres
-        real(kind(0d0)) :: ptilde
-        real(kind(0d0)) :: ptot
-        real(kind(0d0)) :: alf
-        real(kind(0d0)) :: alfgr
-        real(kind(0d0)), dimension(num_fluids) :: alpha
-        real(kind(0d0)) :: gamma
-        real(kind(0d0)) :: pi_inf
-        real(kind(0d0)) :: qv
-        real(kind(0d0)) :: c
-        real(kind(0d0)) :: M00, M10, M01, M20, M11, M02
-        real(kind(0d0)) :: varR, varV
-        real(kind(0d0)), dimension(Nb) :: nR, R, nRdot, Rdot
-        real(kind(0d0)) :: nR3
-        real(kind(0d0)) :: accel
-        real(kind(0d0)) :: int_pres
-        real(kind(0d0)) :: max_pres
-        real(kind(0d0)), dimension(2) :: Re
-        real(kind(0d0)), dimension(6) :: tau_e
-        real(kind(0d0)) :: G
-        real(kind(0d0)) :: dyn_p, Temp
+
+        real(wp) :: lit_gamma, nbub
+        real(wp) :: rho
+        real(wp), dimension(num_dims) :: vel
+        real(wp) :: pres
+        real(wp) :: ptilde
+        real(wp) :: ptot
+        real(wp) :: alf
+        real(wp) :: alfgr
+        real(wp), dimension(num_fluids) :: alpha
+        real(wp) :: gamma
+        real(wp) :: pi_inf
+        real(wp) :: qv
+        real(wp) :: c
+        real(wp) :: M00, M10, M01, M20, M11, M02
+        real(wp) :: varR, varV
+        real(wp), dimension(Nb) :: nR, R, nRdot, Rdot
+        real(wp) :: nR3
+        real(wp) :: accel
+        real(wp) :: int_pres
+        real(wp) :: max_pres
+        real(wp), dimension(2) :: Re
+        real(wp), dimension(6) :: tau_e
+        real(wp) :: G
+        real(wp) :: dyn_p, Temp
 
         integer :: i, j, k, l, s, d !< Generic loop iterator
 
-        real(kind(0d0)) :: nondim_time !< Non-dimensional time
+        real(wp) :: nondim_time !< Non-dimensional time
 
-        real(kind(0d0)) :: tmp !<
+        real(wp) :: tmp !<
             !! Temporary variable to store quantity for mpi_allreduce
 
         integer :: npts !< Number of included integral points
-        real(kind(0d0)) :: rad, thickness !< For integral quantities
+        real(wp) :: rad, thickness !< For integral quantities
         logical :: trigger !< For integral quantities
 
-        real(kind(0d0)) :: rhoYks(1:num_species)
+        real(wp) :: rhoYks(1:num_species)
 
         ! Non-dimensional time calculation
         if (time_stepper == 23) then
             nondim_time = mytime
         else
             if (t_step_old /= dflt_int) then
-                nondim_time = real(t_step + t_step_old, kind(0d0))*dt
+                nondim_time = real(t_step + t_step_old, wp)*dt
             else
-                nondim_time = real(t_step, kind(0d0))*dt
+                nondim_time = real(t_step, wp)*dt
             end if
         end if
 
         do i = 1, num_probes
             ! Zeroing out flow variables for all processors
-            rho = 0d0
+            rho = 0._wp
             do s = 1, num_dims
-                vel(s) = 0d0
+                vel(s) = 0._wp
             end do
-            pres = 0d0
-            gamma = 0d0
-            pi_inf = 0d0
-            qv = 0d0
-            c = 0d0
-            accel = 0d0
-            nR = 0d0; R = 0d0
-            nRdot = 0d0; Rdot = 0d0
-            nbub = 0d0
-            M00 = 0d0
-            M10 = 0d0
-            M01 = 0d0
-            M20 = 0d0
-            M11 = 0d0
-            M02 = 0d0
-            varR = 0d0; varV = 0d0
-            alf = 0d0
+            pres = 0._wp
+            gamma = 0._wp
+            pi_inf = 0._wp
+            qv = 0._wp
+            c = 0._wp
+            accel = 0._wp
+            nR = 0._wp; R = 0._wp
+            nRdot = 0._wp; Rdot = 0._wp
+            nbub = 0._wp
+            M00 = 0._wp
+            M10 = 0._wp
+            M01 = 0._wp
+            M20 = 0._wp
+            M11 = 0._wp
+            M02 = 0._wp
+            varR = 0._wp; varV = 0._wp
+            alf = 0._wp
             do s = 1, (num_dims*(num_dims + 1))/2
-                tau_e(s) = 0d0
+                tau_e(s) = 0._wp
             end do
 
             ! Find probe location in terms of indices on a
@@ -979,7 +981,7 @@ contains
                 if ((probe(i)%x >= x_cb(-1)) .and. (probe(i)%x <= x_cb(m))) then
                     do s = -1, m
                         distx(s) = x_cb(s) - probe(i)%x
-                        if (distx(s) < 0d0) distx(s) = 1000d0
+                        if (distx(s) < 0._wp) distx(s) = 1000._wp
                     end do
                     j = minloc(distx, 1)
                     if (j == 1) j = 2 ! Pick first point if probe is at edge
@@ -1005,7 +1007,7 @@ contains
                         vel(s) = q_cons_vf(cont_idx%end + s)%sf(j - 2, k, l)/rho
                     end do
 
-                    dyn_p = 0.5d0*rho*dot_product(vel, vel)
+                    dyn_p = 0.5_wp*rho*dot_product(vel, vel)
 
                     if (hypoelasticity) then
                         call s_compute_pressure( &
@@ -1022,7 +1024,7 @@ contains
                     end if
 
                     if (model_eqns == 4) then
-                        lit_gamma = 1d0/fluid_pp(1)%gamma + 1d0
+                        lit_gamma = 1._wp/fluid_pp(1)%gamma + 1._wp
                     else if (hypoelasticity) then
                         tau_e(1) = q_cons_vf(stress_idx%end)%sf(j - 2, k, l)/rho
                     end if
@@ -1040,12 +1042,12 @@ contains
                         if (adv_n) then
                             nbub = q_cons_vf(n_idx)%sf(j - 2, k, l)
                         else
-                            nR3 = 0d0
+                            nR3 = 0._wp
                             do s = 1, nb
-                                nR3 = nR3 + weight(s)*(nR(s)**3d0)
+                                nR3 = nR3 + weight(s)*(nR(s)**3._wp)
                             end do
 
-                            nbub = dsqrt((4.d0*pi/3.d0)*nR3/alf)
+                            nbub = sqrt((4._wp*pi/3._wp)*nR3/alf)
                         end if
 #ifdef DEBUG
                         print *, 'In probe, nbub: ', nbub
@@ -1064,8 +1066,8 @@ contains
                             M11 = M11/M00
                             M02 = M02/M00
 
-                            varR = M20 - M10**2d0
-                            varV = M02 - M01**2d0
+                            varR = M20 - M10**2._wp
+                            varV = M02 - M01**2._wp
                         end if
                         R(:) = nR(:)/nbub
                         Rdot(:) = nRdot(:)/nbub
@@ -1076,7 +1078,7 @@ contains
 
                     ! Compute mixture sound Speed
                     call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, &
-                                                  ((gamma + 1d0)*pres + pi_inf)/rho, alpha, 0d0, 0d0, c)
+                                                  ((gamma + 1._wp)*pres + pi_inf)/rho, alpha, 0._wp, 0._wp, c)
 
                     accel = accel_mag(j - 2, k, l)
                 end if
@@ -1091,11 +1093,11 @@ contains
                     if ((probe(i)%y >= y_cb(-1)) .and. (probe(i)%y <= y_cb(n))) then
                         do s = -1, m
                             distx(s) = x_cb(s) - probe(i)%x
-                            if (distx(s) < 0d0) distx(s) = 1000d0
+                            if (distx(s) < 0._wp) distx(s) = 1000._wp
                         end do
                         do s = -1, n
                             disty(s) = y_cb(s) - probe(i)%y
-                            if (disty(s) < 0d0) disty(s) = 1000d0
+                            if (disty(s) < 0._wp) disty(s) = 1000._wp
                         end do
                         j = minloc(distx, 1)
                         k = minloc(disty, 1)
@@ -1111,7 +1113,7 @@ contains
                             vel(s) = q_cons_vf(cont_idx%end + s)%sf(j - 2, k - 2, l)/rho
                         end do
 
-                        dyn_p = 0.5d0*rho*dot_product(vel, vel)
+                        dyn_p = 0.5_wp*rho*dot_product(vel, vel)
 
                         if (hypoelasticity) then
                             call s_compute_pressure( &
@@ -1131,7 +1133,7 @@ contains
                         end if
 
                         if (model_eqns == 4) then
-                            lit_gamma = 1d0/fluid_pp(1)%gamma + 1d0
+                            lit_gamma = 1._wp/fluid_pp(1)%gamma + 1._wp
                         else if (hypoelasticity) then
                             do s = 1, 3
                                 tau_e(s) = q_cons_vf(s)%sf(j - 2, k - 2, l)/rho
@@ -1148,12 +1150,12 @@ contains
                             if (adv_n) then
                                 nbub = q_cons_vf(n_idx)%sf(j - 2, k - 2, l)
                             else
-                                nR3 = 0d0
+                                nR3 = 0._wp
                                 do s = 1, nb
-                                    nR3 = nR3 + weight(s)*(nR(s)**3d0)
+                                    nR3 = nR3 + weight(s)*(nR(s)**3._wp)
                                 end do
 
-                                nbub = dsqrt((4.d0*pi/3.d0)*nR3/alf)
+                                nbub = sqrt((4._wp*pi/3._wp)*nR3/alf)
                             end if
 
                             R(:) = nR(:)/nbub
@@ -1162,7 +1164,7 @@ contains
 
                         ! Compute mixture sound speed
                         call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, &
-                                                      ((gamma + 1d0)*pres + pi_inf)/rho, alpha, 0d0, 0d0, c)
+                                                      ((gamma + 1._wp)*pres + pi_inf)/rho, alpha, 0._wp, 0._wp, c)
 
                         accel = accel_mag(j - 2, k - 2, l)
                     end if
@@ -1173,15 +1175,15 @@ contains
                         if ((probe(i)%z >= z_cb(-1)) .and. (probe(i)%z <= z_cb(p))) then
                             do s = -1, m
                                 distx(s) = x_cb(s) - probe(i)%x
-                                if (distx(s) < 0d0) distx(s) = 1000d0
+                                if (distx(s) < 0._wp) distx(s) = 1000._wp
                             end do
                             do s = -1, n
                                 disty(s) = y_cb(s) - probe(i)%y
-                                if (disty(s) < 0d0) disty(s) = 1000d0
+                                if (disty(s) < 0._wp) disty(s) = 1000._wp
                             end do
                             do s = -1, p
                                 distz(s) = z_cb(s) - probe(i)%z
-                                if (distz(s) < 0d0) distz(s) = 1000d0
+                                if (distz(s) < 0._wp) distz(s) = 1000._wp
                             end do
                             j = minloc(distx, 1)
                             k = minloc(disty, 1)
@@ -1198,7 +1200,7 @@ contains
                                 vel(s) = q_cons_vf(cont_idx%end + s)%sf(j - 2, k - 2, l - 2)/rho
                             end do
 
-                            dyn_p = 0.5d0*rho*dot_product(vel, vel)
+                            dyn_p = 0.5_wp*rho*dot_product(vel, vel)
 
                             if (chemistry) then
                                 do d = 1, num_species
@@ -1223,7 +1225,7 @@ contains
 
                             ! Compute mixture sound speed
                             call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, &
-                                                          ((gamma + 1d0)*pres + pi_inf)/rho, alpha, 0d0, 0d0, c)
+                                                          ((gamma + 1._wp)*pres + pi_inf)/rho, alpha, 0._wp, 0._wp, c)
 
                             accel = accel_mag(j - 2, k - 2, l - 2)
                         end if
@@ -1390,20 +1392,20 @@ contains
         if (integral_wrt .and. bubbles) then
             if (n == 0) then ! 1D simulation
                 do i = 1, num_integrals
-                    int_pres = 0d0
-                    max_pres = 0d0
+                    int_pres = 0._wp
+                    max_pres = 0._wp
                     k = 0; l = 0
                     npts = 0
                     do j = 1, m
-                        pres = 0d0
+                        pres = 0._wp
                         do s = 1, num_dims
-                            vel(s) = 0d0
+                            vel(s) = 0._wp
                         end do
-                        rho = 0d0
-                        pres = 0d0
-                        gamma = 0d0
-                        pi_inf = 0d0
-                        qv = 0d0
+                        rho = 0._wp
+                        pres = 0._wp
+                        gamma = 0._wp
+                        pi_inf = 0._wp
+                        qv = 0._wp
 
                         if ((integral(i)%xmin <= x_cb(j)) .and. (integral(i)%xmax >= x_cb(j))) then
                             npts = npts + 1
@@ -1415,14 +1417,14 @@ contains
 
                             pres = ( &
                                    (q_cons_vf(E_idx)%sf(j, k, l) - &
-                                    0.5d0*(q_cons_vf(mom_idx%beg)%sf(j, k, l)**2.d0)/rho)/ &
-                                   (1.d0 - q_cons_vf(alf_idx)%sf(j, k, l)) - &
+                                    0.5_wp*(q_cons_vf(mom_idx%beg)%sf(j, k, l)**2._wp)/rho)/ &
+                                   (1._wp - q_cons_vf(alf_idx)%sf(j, k, l)) - &
                                    pi_inf - qv &
                                    )/gamma
-                            int_pres = int_pres + (pres - 1.d0)**2.d0
+                            int_pres = int_pres + (pres - 1._wp)**2._wp
                         end if
                     end do
-                    int_pres = dsqrt(int_pres/(1.d0*npts))
+                    int_pres = sqrt(int_pres/(1._wp*npts))
 
                     if (num_procs > 1) then
                         tmp = int_pres
@@ -1445,8 +1447,8 @@ contains
                 thickness = integral(1)%xmin
 
                 do i = 1, num_integrals
-                    int_pres = 0d0
-                    max_pres = 0d0
+                    int_pres = 0._wp
+                    max_pres = 0._wp
                     l = 0
                     npts = 0
                     do j = 1, m
@@ -1454,28 +1456,28 @@ contains
                             trigger = .false.
                             if (i == 1) then
                                 !inner portion
-                                if (dsqrt(x_cb(j)**2.d0 + y_cb(k)**2.d0) < (rad - 0.5d0*thickness)) &
+                                if (sqrt(x_cb(j)**2._wp + y_cb(k)**2._wp) < (rad - 0.5_wp*thickness)) &
                                     trigger = .true.
                             elseif (i == 2) then
                                 !net region
-                                if (dsqrt(x_cb(j)**2.d0 + y_cb(k)**2.d0) > (rad - 0.5d0*thickness) .and. &
-                                    dsqrt(x_cb(j)**2.d0 + y_cb(k)**2.d0) < (rad + 0.5d0*thickness)) &
+                                if (sqrt(x_cb(j)**2._wp + y_cb(k)**2._wp) > (rad - 0.5_wp*thickness) .and. &
+                                    sqrt(x_cb(j)**2._wp + y_cb(k)**2._wp) < (rad + 0.5_wp*thickness)) &
                                     trigger = .true.
                             elseif (i == 3) then
                                 !everything else
-                                if (dsqrt(x_cb(j)**2.d0 + y_cb(k)**2.d0) > (rad + 0.5d0*thickness)) &
+                                if (sqrt(x_cb(j)**2._wp + y_cb(k)**2._wp) > (rad + 0.5_wp*thickness)) &
                                     trigger = .true.
                             end if
 
-                            pres = 0d0
+                            pres = 0._wp
                             do s = 1, num_dims
-                                vel(s) = 0d0
+                                vel(s) = 0._wp
                             end do
-                            rho = 0d0
-                            pres = 0d0
-                            gamma = 0d0
-                            pi_inf = 0d0
-                            qv = 0d0
+                            rho = 0._wp
+                            pres = 0._wp
+                            gamma = 0._wp
+                            pi_inf = 0._wp
+                            qv = 0._wp
 
                             if (trigger) then
                                 npts = npts + 1
@@ -1487,21 +1489,21 @@ contains
 
                                 pres = ( &
                                        (q_cons_vf(E_idx)%sf(j, k, l) - &
-                                        0.5d0*(q_cons_vf(mom_idx%beg)%sf(j, k, l)**2.d0)/rho)/ &
-                                       (1.d0 - q_cons_vf(alf_idx)%sf(j, k, l)) - &
+                                        0.5_wp*(q_cons_vf(mom_idx%beg)%sf(j, k, l)**2._wp)/rho)/ &
+                                       (1._wp - q_cons_vf(alf_idx)%sf(j, k, l)) - &
                                        pi_inf - qv &
                                        )/gamma
-                                int_pres = int_pres + abs(pres - 1.d0)
-                                max_pres = max(max_pres, abs(pres - 1.d0))
+                                int_pres = int_pres + abs(pres - 1._wp)
+                                max_pres = max(max_pres, abs(pres - 1._wp))
                             end if
 
                         end do
                     end do
 
                     if (npts > 0) then
-                        int_pres = int_pres/(1.d0*npts)
+                        int_pres = int_pres/(1._wp*npts)
                     else
-                        int_pres = 0.d0
+                        int_pres = 0._wp
                     end if
 
                     if (num_procs > 1) then
@@ -1531,7 +1533,7 @@ contains
         !!      all of the time-steps and the simulation run-time.
     subroutine s_close_run_time_information_file
 
-        real(kind(0d0)) :: run_time !< Run-time of the simulation
+        real(wp) :: run_time !< Run-time of the simulation
         ! Writing the footer of and closing the run-time information file
         write (3, '(A)') '----------------------------------------'// &
             '----------------------------------------'
@@ -1569,14 +1571,14 @@ contains
 
         ! Allocating/initializing ICFL, VCFL, CCFL and Rc stability criteria
         @:ALLOCATE(icfl_sf(0:m, 0:n, 0:p))
-        icfl_max = 0d0
+        icfl_max = 0._wp
 
         if (viscous) then
             @:ALLOCATE(vcfl_sf(0:m, 0:n, 0:p))
             @:ALLOCATE(Rc_sf  (0:m, 0:n, 0:p))
 
-            vcfl_max = 0d0
-            Rc_min = 1d3
+            vcfl_max = 0._wp
+            Rc_min = 1e3_wp
         end if
 
     end subroutine s_initialize_data_output_module
diff --git a/src/simulation/m_derived_variables.f90 b/src/simulation/m_derived_variables.f90
index 1c4e838a5..6e45fe59f 100644
--- a/src/simulation/m_derived_variables.f90
+++ b/src/simulation/m_derived_variables.f90
@@ -39,15 +39,15 @@ module m_derived_variables
     !! active coordinate directions, the centered family of the finite-difference
     !! schemes is used.
     !> @{
-    real(kind(0d0)), public, allocatable, dimension(:, :) :: fd_coeff_x
-    real(kind(0d0)), public, allocatable, dimension(:, :) :: fd_coeff_y
-    real(kind(0d0)), public, allocatable, dimension(:, :) :: fd_coeff_z
+    real(wp), public, allocatable, dimension(:, :) :: fd_coeff_x
+    real(wp), public, allocatable, dimension(:, :) :: fd_coeff_y
+    real(wp), public, allocatable, dimension(:, :) :: fd_coeff_z
     !> @}
 
     ! @name Variables for computing acceleration
     !> @{
-    real(kind(0d0)), public, allocatable, dimension(:, :, :) :: accel_mag
-    real(kind(0d0)), public, allocatable, dimension(:, :, :) :: x_accel, y_accel, z_accel
+    real(wp), public, allocatable, dimension(:, :, :) :: accel_mag
+    real(wp), public, allocatable, dimension(:, :, :) :: x_accel, y_accel, z_accel
     !> @}
 
 contains
@@ -148,12 +148,12 @@ subroutine s_compute_derived_variables(t_step)
                 do j = 0, n
                     do i = 0, m
                         if (p > 0) then
-                            accel_mag(i, j, k) = sqrt(x_accel(i, j, k)**2d0 + &
-                                                      y_accel(i, j, k)**2d0 + &
-                                                      z_accel(i, j, k)**2d0)
+                            accel_mag(i, j, k) = sqrt(x_accel(i, j, k)**2._wp + &
+                                                      y_accel(i, j, k)**2._wp + &
+                                                      z_accel(i, j, k)**2._wp)
                         elseif (n > 0) then
-                            accel_mag(i, j, k) = sqrt(x_accel(i, j, k)**2d0 + &
-                                                      y_accel(i, j, k)**2d0)
+                            accel_mag(i, j, k) = sqrt(x_accel(i, j, k)**2._wp + &
+                                                      y_accel(i, j, k)**2._wp)
                         else
                             accel_mag(i, j, k) = x_accel(i, j, k)
                         end if
@@ -188,7 +188,7 @@ subroutine s_derive_acceleration_component(i, q_prim_vf0, q_prim_vf1, &
         type(scalar_field), dimension(sys_size), intent(in) :: q_prim_vf2
         type(scalar_field), dimension(sys_size), intent(in) :: q_prim_vf3
 
-        real(kind(0d0)), dimension(0:m, 0:n, 0:p), intent(out) :: q_sf
+        real(wp), dimension(0:m, 0:n, 0:p), intent(out) :: q_sf
 
         integer :: j, k, l, r !< Generic loop iterators
 
@@ -198,10 +198,10 @@ subroutine s_derive_acceleration_component(i, q_prim_vf0, q_prim_vf1, &
                 do k = 0, n
                     do j = 0, m
 
-                        q_sf(j, k, l) = (11d0*q_prim_vf0(mom_idx%beg)%sf(j, k, l) &
-                                         - 18d0*q_prim_vf1(mom_idx%beg)%sf(j, k, l) &
-                                         + 9d0*q_prim_vf2(mom_idx%beg)%sf(j, k, l) &
-                                         - 2d0*q_prim_vf3(mom_idx%beg)%sf(j, k, l))/(6d0*dt)
+                        q_sf(j, k, l) = (11._wp*q_prim_vf0(mom_idx%beg)%sf(j, k, l) &
+                                         - 18._wp*q_prim_vf1(mom_idx%beg)%sf(j, k, l) &
+                                         + 9._wp*q_prim_vf2(mom_idx%beg)%sf(j, k, l) &
+                                         - 2._wp*q_prim_vf3(mom_idx%beg)%sf(j, k, l))/(6._wp*dt)
 
                         do r = -fd_number, fd_number
                             if (n == 0) then ! 1D simulation
@@ -244,10 +244,10 @@ subroutine s_derive_acceleration_component(i, q_prim_vf0, q_prim_vf1, &
                 do k = 0, n
                     do j = 0, m
 
-                        q_sf(j, k, l) = (11d0*q_prim_vf0(mom_idx%beg + 1)%sf(j, k, l) &
-                                         - 18d0*q_prim_vf1(mom_idx%beg + 1)%sf(j, k, l) &
-                                         + 9d0*q_prim_vf2(mom_idx%beg + 1)%sf(j, k, l) &
-                                         - 2d0*q_prim_vf3(mom_idx%beg + 1)%sf(j, k, l))/(6d0*dt)
+                        q_sf(j, k, l) = (11._wp*q_prim_vf0(mom_idx%beg + 1)%sf(j, k, l) &
+                                         - 18._wp*q_prim_vf1(mom_idx%beg + 1)%sf(j, k, l) &
+                                         + 9._wp*q_prim_vf2(mom_idx%beg + 1)%sf(j, k, l) &
+                                         - 2._wp*q_prim_vf3(mom_idx%beg + 1)%sf(j, k, l))/(6._wp*dt)
 
                         do r = -fd_number, fd_number
                             if (p == 0) then ! 2D simulation
@@ -265,7 +265,7 @@ subroutine s_derive_acceleration_component(i, q_prim_vf0, q_prim_vf1, &
                                                     q_prim_vf0(mom_idx%beg + 1)%sf(j, r + k, l) &
                                                     + q_prim_vf0(mom_idx%end)%sf(j, k, l)*fd_coeff_z(r, l)* &
                                                     q_prim_vf0(mom_idx%beg + 1)%sf(j, k, r + l)/y_cc(k) &
-                                                    - (q_prim_vf0(mom_idx%end)%sf(j, k, l)**2d0)/y_cc(k)
+                                                    - (q_prim_vf0(mom_idx%end)%sf(j, k, l)**2._wp)/y_cc(k)
                                 else
                                     q_sf(j, k, l) = q_sf(j, k, l) &
                                                     + q_prim_vf0(mom_idx%beg)%sf(j, k, l)*fd_coeff_x(r, j)* &
@@ -286,10 +286,10 @@ subroutine s_derive_acceleration_component(i, q_prim_vf0, q_prim_vf1, &
             do l = 0, p
                 do k = 0, n
                     do j = 0, m
-                        q_sf(j, k, l) = (11d0*q_prim_vf0(mom_idx%end)%sf(j, k, l) &
-                                         - 18d0*q_prim_vf1(mom_idx%end)%sf(j, k, l) &
-                                         + 9d0*q_prim_vf2(mom_idx%end)%sf(j, k, l) &
-                                         - 2d0*q_prim_vf3(mom_idx%end)%sf(j, k, l))/(6d0*dt)
+                        q_sf(j, k, l) = (11._wp*q_prim_vf0(mom_idx%end)%sf(j, k, l) &
+                                         - 18._wp*q_prim_vf1(mom_idx%end)%sf(j, k, l) &
+                                         + 9._wp*q_prim_vf2(mom_idx%end)%sf(j, k, l) &
+                                         - 2._wp*q_prim_vf3(mom_idx%end)%sf(j, k, l))/(6._wp*dt)
 
                         do r = -fd_number, fd_number
                             if (grid_geometry == 3) then
diff --git a/src/simulation/m_fftw.fpp b/src/simulation/m_fftw.fpp
index c647f593e..9ab5c0c5f 100644
--- a/src/simulation/m_fftw.fpp
+++ b/src/simulation/m_fftw.fpp
@@ -51,9 +51,9 @@ module m_fftw
 #if defined(MFC_OpenACC)
     !$acc declare create(real_size, cmplx_size, x_size, batch_size, Nfq)
 
-    real(kind(0d0)), allocatable, target :: data_real_gpu(:)
-    complex(kind(0d0)), allocatable, target :: data_cmplx_gpu(:)
-    complex(kind(0d0)), allocatable, target :: data_fltr_cmplx_gpu(:)
+    real(dp), allocatable, target :: data_real_gpu(:)
+    complex(dp), allocatable, target :: data_cmplx_gpu(:)
+    complex(dp), allocatable, target :: data_fltr_cmplx_gpu(:)
 !$acc declare create(data_real_gpu, data_cmplx_gpu, data_fltr_cmplx_gpu)
 
 #if defined(__PGI)
@@ -146,7 +146,7 @@ contains
         do k = 1, sys_size
             do j = 0, m
                 do l = 1, cmplx_size
-                    data_fltr_cmplx_gpu(l + j*cmplx_size + (k - 1)*cmplx_size*x_size) = (0d0, 0d0)
+                    data_fltr_cmplx_gpu(l + j*cmplx_size + (k - 1)*cmplx_size*x_size) = (0_dp, 0_dp)
                 end do
             end do
         end do
@@ -198,7 +198,7 @@ contains
         do k = 1, sys_size
             do j = 0, m
                 do l = 0, p
-                    data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size) = data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size)/real(real_size, kind(0d0))
+                    data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size) = data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size)/real(real_size, dp)
                     q_cons_vf(k)%sf(j, 0, l) = data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size)
                 end do
             end do
@@ -210,7 +210,7 @@ contains
             do k = 1, sys_size
                 do j = 0, m
                     do l = 1, cmplx_size
-                        data_fltr_cmplx_gpu(l + j*cmplx_size + (k - 1)*cmplx_size*x_size) = (0d0, 0d0)
+                        data_fltr_cmplx_gpu(l + j*cmplx_size + (k - 1)*cmplx_size*x_size) = (0_dp, 0_dp)
                     end do
                 end do
             end do
@@ -233,7 +233,7 @@ contains
 #endif
             !$acc end host_data
 
-            Nfq = min(floor(2d0*real(i, kind(0d0))*pi), cmplx_size)
+            Nfq = min(floor(2_dp*real(i, dp)*pi), cmplx_size)
             !$acc update device(Nfq)
 
             !$acc parallel loop collapse(3) gang vector default(present)
@@ -258,7 +258,7 @@ contains
             do k = 1, sys_size
                 do j = 0, m
                     do l = 0, p
-                        data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size) = data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size)/real(real_size, kind(0d0))
+                        data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size) = data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size)/real(real_size, dp)
                         q_cons_vf(k)%sf(j, i, l) = data_real_gpu(l + j*real_size + 1 + (k - 1)*real_size*x_size)
                     end do
                 end do
@@ -270,27 +270,27 @@ contains
         Nfq = 3
         do j = 0, m
             do k = 1, sys_size
-                data_fltr_cmplx(:) = (0d0, 0d0)
+                data_fltr_cmplx(:) = (0_dp, 0_dp)
                 data_real(1:p + 1) = q_cons_vf(k)%sf(j, 0, 0:p)
                 call fftw_execute_dft_r2c(fwd_plan, data_real, data_cmplx)
                 data_fltr_cmplx(1:Nfq) = data_cmplx(1:Nfq)
                 call fftw_execute_dft_c2r(bwd_plan, data_fltr_cmplx, data_real)
-                data_real(:) = data_real(:)/real(real_size, kind(0d0))
+                data_real(:) = data_real(:)/real(real_size, dp)
                 q_cons_vf(k)%sf(j, 0, 0:p) = data_real(1:p + 1)
             end do
         end do
 
         ! Apply Fourier filter to additional rings
         do i = 1, fourier_rings
-            Nfq = min(floor(2d0*real(i, kind(0d0))*pi), cmplx_size)
+            Nfq = min(floor(2_dp*real(i, dp)*pi), cmplx_size)
             do j = 0, m
                 do k = 1, sys_size
-                    data_fltr_cmplx(:) = (0d0, 0d0)
+                    data_fltr_cmplx(:) = (0_dp, 0_dp)
                     data_real(1:p + 1) = q_cons_vf(k)%sf(j, i, 0:p)
                     call fftw_execute_dft_r2c(fwd_plan, data_real, data_cmplx)
                     data_fltr_cmplx(1:Nfq) = data_cmplx(1:Nfq)
                     call fftw_execute_dft_c2r(bwd_plan, data_fltr_cmplx, data_real)
-                    data_real(:) = data_real(:)/real(real_size, kind(0d0))
+                    data_real(:) = data_real(:)/real(real_size, dp)
                     q_cons_vf(k)%sf(j, i, 0:p) = data_real(1:p + 1)
                 end do
             end do
diff --git a/src/simulation/m_global_parameters.fpp b/src/simulation/m_global_parameters.fpp
index db5d17656..52a6b1228 100644
--- a/src/simulation/m_global_parameters.fpp
+++ b/src/simulation/m_global_parameters.fpp
@@ -30,7 +30,7 @@ module m_global_parameters
 
     implicit none
 
-    real(kind(0d0)) :: time = 0
+    real(wp) :: time = 0
 
     ! Logistics ================================================================
     integer :: num_procs             !< Number of processors
@@ -61,21 +61,24 @@ module m_global_parameters
 
     !> @name Cell-boundary (CB) locations in the x-, y- and z-directions, respectively
     !> @{
-    real(kind(0d0)), target, allocatable, dimension(:) :: x_cb, y_cb, z_cb
+
+    real(wp), target, allocatable, dimension(:) :: x_cb, y_cb, z_cb
     !> @}
 
     !> @name Cell-center (CC) locations in the x-, y- and z-directions, respectively
     !> @{
-    real(kind(0d0)), target, allocatable, dimension(:) :: x_cc, y_cc, z_cc
+
+    real(wp), target, allocatable, dimension(:) :: x_cc, y_cc, z_cc
     !> @}
     !type(bounds_info) :: x_domain, y_domain, z_domain !<
     !! Locations of the domain bounds in the x-, y- and z-coordinate directions
     !> @name Cell-width distributions in the x-, y- and z-directions, respectively
     !> @{
-    real(kind(0d0)), target, allocatable, dimension(:) :: dx, dy, dz
+
+    real(wp), target, allocatable, dimension(:) :: dx, dy, dz
     !> @}
 
-    real(kind(0d0)) :: dt !< Size of the time-step
+    real(wp) :: dt !< Size of the time-step
 
     !$acc declare create(x_cb, y_cb, z_cb, x_cc, y_cc, z_cc, dx, dy, dz, dt, m, n, p)
 
@@ -88,7 +91,7 @@ module m_global_parameters
     !> @name Starting time, stopping time, and time between backups, simulation time,
     !! and prescribed cfl respectively
     !> @{
-    real(kind(0d0)) :: t_stop, t_save, cfl_target
+    real(wp) :: t_stop, t_save, cfl_target
     integer :: n_start
     !> @}
     !$acc declare create(cfl_target)
@@ -119,7 +122,7 @@ module m_global_parameters
         logical, parameter :: mapped_weno = (${mapped_weno}$ /= 0)  !< WENO-M (WENO with mapping of nonlinear weights)
         logical, parameter :: wenoz = (${wenoz}$ /= 0)              !< WENO-Z
         logical, parameter :: teno = (${teno}$ /= 0)                !< TENO (Targeted ENO)
-        real(kind(0d0)), parameter :: wenoz_q = ${wenoz_q}$         !< Power constant for WENO-Z
+        real(wp), parameter :: wenoz_q = ${wenoz_q}$         !< Power constant for WENO-Z
     #:else
         integer :: weno_polyn     !< Degree of the WENO polynomials (polyn)
         integer :: weno_order     !< Order of the WENO reconstruction
@@ -129,11 +132,11 @@ module m_global_parameters
         logical :: mapped_weno    !< WENO-M (WENO with mapping of nonlinear weights)
         logical :: wenoz          !< WENO-Z
         logical :: teno           !< TENO (Targeted ENO)
-        real(kind(0d0)) :: wenoz_q  !< Power constant for WENO-Z
+        real(wp) :: wenoz_q  !< Power constant for WENO-Z
     #:endif
 
-    real(kind(0d0)) :: weno_eps       !< Binding for the WENO nonlinear weights
-    real(kind(0d0)) :: teno_CT        !< Smoothness threshold for TENO
+    real(wp) :: weno_eps       !< Binding for the WENO nonlinear weights
+    real(wp) :: teno_CT        !< Smoothness threshold for TENO
     logical :: mp_weno        !< Monotonicity preserving (MP) WENO
     logical :: weno_avg       ! Average left/right cell-boundary states
     logical :: weno_Re_flux   !< WENO reconstruct velocity gradients for viscous stress tensor
@@ -158,10 +161,10 @@ module m_global_parameters
     !< amplitude, frequency, and phase shift sinusoid in each direction
     #:for dir in {'x', 'y', 'z'}
         #:for param in {'k','w','p','g'}
-            real(kind(0d0)) :: ${param}$_${dir}$
+            real(wp) :: ${param}$_${dir}$
         #:endfor
     #:endfor
-    real(kind(0d0)), dimension(3) :: accel_bf
+    real(wp), dimension(3) :: accel_bf
     !$acc declare create(accel_bf)
 
     integer :: cpu_start, cpu_end, cpu_rate
@@ -174,8 +177,8 @@ module m_global_parameters
 
     logical :: relax          !< activate phase change
     integer :: relax_model    !< Relaxation model
-    real(kind(0d0)) :: palpha_eps     !< trigger parameter for the p relaxation procedure, phase change model
-    real(kind(0d0)) :: ptgalpha_eps   !< trigger parameter for the pTg relaxation procedure, phase change model
+    real(wp) :: palpha_eps     !< trigger parameter for the p relaxation procedure, phase change model
+    real(wp) :: ptgalpha_eps   !< trigger parameter for the pTg relaxation procedure, phase change model
 
 !#ifndef _CRAYFTN
 !$acc declare create(relax, relax_model, palpha_eps,ptgalpha_eps)
@@ -260,7 +263,7 @@ module m_global_parameters
     ! values or simply, the unaltered left and right, WENO-reconstructed, cell-
     ! boundary values.
     !> @{
-    real(kind(0d0)) :: wa_flg
+    real(wp) :: wa_flg
     !> @{
 
     !$acc declare create(wa_flg)
@@ -271,7 +274,7 @@ module m_global_parameters
     !! the dimensionally split system of equations.
     !> @{
     integer, dimension(3) :: dir_idx
-    real(kind(0d0)), dimension(3) :: dir_flg
+    real(wp), dimension(3) :: dir_flg
     integer, dimension(3) :: dir_idx_tau !!used for hypoelasticity=true
     !> @}
 
@@ -320,7 +323,7 @@ module m_global_parameters
 
     !> @name Reference density and pressure for Tait EOS
     !> @{
-    real(kind(0d0)) :: rhoref, pref
+    real(wp) :: rhoref, pref
     !> @}
     !$acc declare create(rhoref, pref)
 
@@ -349,14 +352,14 @@ module m_global_parameters
         integer :: nb       !< Number of eq. bubble sizes
     #:endif
 
-    real(kind(0d0)) :: R0ref    !< Reference bubble size
-    real(kind(0d0)) :: Ca       !< Cavitation number
-    real(kind(0d0)) :: Web      !< Weber number
-    real(kind(0d0)) :: Re_inv   !< Inverse Reynolds number
+    real(wp) :: R0ref    !< Reference bubble size
+    real(wp) :: Ca       !< Cavitation number
+    real(wp) :: Web      !< Weber number
+    real(wp) :: Re_inv   !< Inverse Reynolds number
 
-    real(kind(0d0)), dimension(:), allocatable :: weight !< Simpson quadrature weights
-    real(kind(0d0)), dimension(:), allocatable :: R0     !< Bubble sizes
-    real(kind(0d0)), dimension(:), allocatable :: V0     !< Bubble velocities
+    real(wp), dimension(:), allocatable :: weight !< Simpson quadrature weights
+    real(wp), dimension(:), allocatable :: R0     !< Bubble sizes
+    real(wp), dimension(:), allocatable :: V0     !< Bubble velocities
     !$acc declare create(weight, R0, V0)
 
     logical :: bubbles      !< Bubbles on/off
@@ -368,10 +371,10 @@ module m_global_parameters
     integer :: bubble_model !< Gilmore or Keller--Miksis bubble model
     integer :: thermal      !< Thermal behavior. 1 = adiabatic, 2 = isotherm, 3 = transfer
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: ptil  !< Pressure modification
+    real(wp), allocatable, dimension(:, :, :) :: ptil  !< Pressure modification
     !$acc declare create(ptil)
 
-    real(kind(0d0)) :: poly_sigma  !< log normal sigma for polydisperse PDF
+    real(wp) :: poly_sigma  !< log normal sigma for polydisperse PDF
 
     logical :: qbmm      !< Quadrature moment method
     integer, parameter :: nmom = 6 !< Number of carried moments per R0 location
@@ -379,7 +382,7 @@ module m_global_parameters
     integer :: nmomtot   !< Total number of carried moments moments/transport equations
     integer :: R0_type
 
-    real(kind(0d0)) :: pi_fac   !< Factor for artificial pi_inf
+    real(wp) :: pi_fac   !< Factor for artificial pi_inf
 
     #:if not MFC_CASE_OPTIMIZATION
         !$acc declare create(nb)
@@ -398,16 +401,17 @@ module m_global_parameters
 
     !> @name Physical bubble parameters (see Ando 2010, Preston 2007)
     !> @{
-    real(kind(0d0)) :: R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, pv, M_n, M_v
+
+    real(wp) :: R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, pv, M_n, M_v
     !$acc declare create(R_n, R_v, phi_vn, phi_nv, Pe_c, Tw, pv, M_n, M_v)
 
-    real(kind(0d0)), dimension(:), allocatable :: k_n, k_v, pb0, mass_n0, mass_v0, Pe_T
-    real(kind(0d0)), dimension(:), allocatable :: Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN
+    real(wp), dimension(:), allocatable :: k_n, k_v, pb0, mass_n0, mass_v0, Pe_T
+    real(wp), dimension(:), allocatable :: Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN
     !$acc declare create( k_n, k_v, pb0, mass_n0, mass_v0, Pe_T, Re_trans_T, Re_trans_c, Im_trans_T, Im_trans_c, omegaN)
 
-    real(kind(0d0)) :: mul0, ss, gamma_v, mu_v
-    real(kind(0d0)) :: gamma_m, gamma_n, mu_n
-    real(kind(0d0)) :: gam
+    real(wp) :: mul0, ss, gamma_v, mu_v
+    real(wp) :: gamma_m, gamma_n, mu_n
+    real(wp) :: gam
     !> @}
 
     !$acc declare create(mul0, ss, gamma_v, mu_v, gamma_m, gamma_n, mu_n, gam)
@@ -422,7 +426,8 @@ module m_global_parameters
 
     !> @name Surface tension parameters
     !> @{
-    real(kind(0d0)) :: sigma
+
+    real(wp) :: sigma
     logical :: surface_tension
     !$acc declare create(sigma, surface_tension)
     !> @}
@@ -437,11 +442,11 @@ module m_global_parameters
 
     !$acc declare create(momxb, momxe, advxb, advxe, contxb, contxe, intxb, intxe, bubxb, bubxe, strxb, strxe,  chemxb, chemxe)
 
-    real(kind(0d0)), allocatable, dimension(:) :: gammas, gs_min, pi_infs, ps_inf, cvs, qvs, qvps
+    real(wp), allocatable, dimension(:) :: gammas, gs_min, pi_infs, ps_inf, cvs, qvs, qvps
     !$acc declare create(gammas, gs_min, pi_infs, ps_inf, cvs, qvs, qvps)
 
-    real(kind(0d0)) :: mytime       !< Current simulation time
-    real(kind(0d0)) :: finaltime    !< Final simulation time
+    real(wp) :: mytime       !< Current simulation time
+    real(wp) :: finaltime    !< Final simulation time
 
     logical :: weno_flat, riemann_flat, rdma_mpi
 
@@ -536,8 +541,8 @@ contains
 
         #:for DIM in ['x', 'y', 'z']
             #:for DIR in [1, 2, 3]
-                bc_${DIM}$%vb${DIR}$ = 0d0
-                bc_${DIM}$%ve${DIR}$ = 0d0
+                bc_${DIM}$%vb${DIR}$ = 0._wp
+                bc_${DIM}$%ve${DIR}$ = 0._wp
             #:endfor
         #:endfor
 
@@ -549,9 +554,9 @@ contains
         do i = 1, num_fluids_max
             fluid_pp(i)%gamma = dflt_real
             fluid_pp(i)%pi_inf = dflt_real
-            fluid_pp(i)%cv = 0d0
-            fluid_pp(i)%qv = 0d0
-            fluid_pp(i)%qvp = 0d0
+            fluid_pp(i)%cv = 0._wp
+            fluid_pp(i)%qv = 0._wp
+            fluid_pp(i)%qvp = 0._wp
             fluid_pp(i)%Re(:) = dflt_real
             fluid_pp(i)%mul0 = dflt_real
             fluid_pp(i)%ss = dflt_real
@@ -560,7 +565,7 @@ contains
             fluid_pp(i)%M_v = dflt_real
             fluid_pp(i)%mu_v = dflt_real
             fluid_pp(i)%k_v = dflt_real
-            fluid_pp(i)%G = 0d0
+            fluid_pp(i)%G = 0._wp
         end do
 
         ! Tait EOS
@@ -590,7 +595,7 @@ contains
         adv_n = .false.
         adap_dt = .false.
 
-        pi_fac = 1d0
+        pi_fac = 1._wp
 
         ! User inputs for qbmm for simulation code
         qbmm = .false.
@@ -780,9 +785,9 @@ contains
                     @:ALLOCATE(bub_idx%ps(nb), bub_idx%ms(nb))
 
                     if (num_fluids == 1) then
-                        gam = 1.d0/fluid_pp(num_fluids + 1)%gamma + 1.d0
+                        gam = 1._wp/fluid_pp(num_fluids + 1)%gamma + 1._wp
                     else
-                        gam = 1.d0/fluid_pp(num_fluids)%gamma + 1.d0
+                        gam = 1._wp/fluid_pp(num_fluids)%gamma + 1._wp
                     end if
 
                     if (qbmm) then
@@ -814,11 +819,11 @@ contains
                     end if
 
                     if (nb == 1) then
-                        weight(:) = 1d0
-                        R0(:) = 1d0
-                        V0(:) = 1d0
+                        weight(:) = 1._wp
+                        R0(:) = 1._wp
+                        V0(:) = 1._wp
                     else if (nb > 1) then
-                        V0(:) = 1d0
+                        V0(:) = 1._wp
                         !R0 and weight initialized in s_simpson
                     else
                         stop 'Invalid value of nb'
@@ -827,8 +832,8 @@ contains
                     !Initialize pref,rhoref for polytropic qbmm (done in s_initialize_nonpoly for non-polytropic)
                     if (.not. qbmm) then
                         if (polytropic) then
-                            rhoref = 1.d0
-                            pref = 1.d0
+                            rhoref = 1._wp
+                            pref = 1._wp
                         end if
                     end if
 
@@ -841,9 +846,9 @@ contains
                             if ((f_is_default(Web))) then
                                 pb0 = pref
                                 pb0 = pb0/pref
-                                pref = 1d0
+                                pref = 1._wp
                             end if
-                            rhoref = 1d0
+                            rhoref = 1._wp
                         end if
                     end if
                 end if
@@ -917,18 +922,18 @@ contains
                         end if
                     end do
                     if (nb == 1) then
-                        weight(:) = 1d0
-                        R0(:) = 1d0
-                        V0(:) = 0d0
+                        weight(:) = 1._wp
+                        R0(:) = 1._wp
+                        V0(:) = 0._wp
                     else if (nb > 1) then
-                        V0(:) = 1d0
+                        V0(:) = 1._wp
                     else
                         stop 'Invalid value of nb'
                     end if
 
                     if (polytropic) then
-                        rhoref = 1.d0
-                        pref = 1.d0
+                        rhoref = 1._wp
+                        pref = 1._wp
                     end if
                 end if
             end if
@@ -940,8 +945,8 @@ contains
                 if (fluid_pp(i)%Re(2) > 0) Re_size(2) = Re_size(2) + 1
             end do
 
-            if (Re_size(1) > 0d0) shear_stress = .true.
-            if (Re_size(2) > 0d0) bulk_stress = .true.
+            if (Re_size(1) > 0._wp) shear_stress = .true.
+            if (Re_size(2) > 0._wp) bulk_stress = .true.
 
             !$acc update device(Re_size, viscous, shear_stress, bulk_stress)
 
@@ -1003,7 +1008,7 @@ contains
         ! using the arithmetic mean of left and right, WENO-reconstructed,
         ! cell-boundary values or otherwise, the unaltered left and right,
         ! WENO-reconstructed, cell-boundary values
-        wa_flg = 0d0; if (weno_avg) wa_flg = 1d0
+        wa_flg = 0._wp; if (weno_avg) wa_flg = 1._wp
         !$acc update device(wa_flg)
 
         ! Resort to default WENO-JS if no other WENO scheme is selected
diff --git a/src/simulation/m_hypoelastic.fpp b/src/simulation/m_hypoelastic.fpp
index 43b600cd3..33ebb8fe6 100644
--- a/src/simulation/m_hypoelastic.fpp
+++ b/src/simulation/m_hypoelastic.fpp
@@ -22,15 +22,15 @@ module m_hypoelastic
     private; public :: s_initialize_hypoelastic_module, &
  s_compute_hypoelastic_rhs
 
-    real(kind(0d0)), allocatable, dimension(:) :: Gs
+    real(wp), allocatable, dimension(:) :: Gs
     !$acc declare create(Gs)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: du_dx, du_dy, du_dz
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: dv_dx, dv_dy, dv_dz
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: dw_dx, dw_dy, dw_dz
+    real(wp), allocatable, dimension(:, :, :) :: du_dx, du_dy, du_dz
+    real(wp), allocatable, dimension(:, :, :) :: dv_dx, dv_dy, dv_dz
+    real(wp), allocatable, dimension(:, :, :) :: dw_dx, dw_dy, dw_dz
     !$acc declare create(du_dx,du_dy,du_dz,dv_dx,dv_dy,dv_dz,dw_dx,dw_dy,dw_dz)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: rho_K_field, G_K_field
+    real(wp), allocatable, dimension(:, :, :) :: rho_K_field, G_K_field
     !$acc declare create(rho_K_field, G_K_field)
 
 contains
@@ -68,7 +68,7 @@ contains
         type(scalar_field), dimension(sys_size), intent(in) :: q_prim_vf
         type(scalar_field), dimension(sys_size), intent(inout) :: rhs_vf
 
-        real(kind(0d0)) :: rho_K, G_K
+        real(wp) :: rho_K, G_K
 
         integer :: i, k, l, q !< Loop variables
         integer :: ndirs  !< Number of coordinate directions
@@ -85,10 +85,10 @@ contains
                     do k = 0, m
                         du_dx(k, l, q) = &
                             (q_prim_vf(momxb)%sf(k - 2, l, q) &
-                             - 8d0*q_prim_vf(momxb)%sf(k - 1, l, q) &
-                             + 8d0*q_prim_vf(momxb)%sf(k + 1, l, q) &
+                             - 8._wp*q_prim_vf(momxb)%sf(k - 1, l, q) &
+                             + 8._wp*q_prim_vf(momxb)%sf(k + 1, l, q) &
                              - q_prim_vf(momxb)%sf(k + 2, l, q)) &
-                            /(12d0*dx(k))
+                            /(12._wp*dx(k))
                     end do
                 end do
             end do
@@ -100,22 +100,22 @@ contains
                         do k = 0, m
                             du_dy(k, l, q) = &
                                 (q_prim_vf(momxb)%sf(k, l - 2, q) &
-                                 - 8d0*q_prim_vf(momxb)%sf(k, l - 1, q) &
-                                 + 8d0*q_prim_vf(momxb)%sf(k, l + 1, q) &
+                                 - 8._wp*q_prim_vf(momxb)%sf(k, l - 1, q) &
+                                 + 8._wp*q_prim_vf(momxb)%sf(k, l + 1, q) &
                                  - q_prim_vf(momxb)%sf(k, l + 2, q)) &
-                                /(12d0*dy(l))
+                                /(12._wp*dy(l))
                             dv_dx(k, l, q) = &
                                 (q_prim_vf(momxb + 1)%sf(k - 2, l, q) &
-                                 - 8d0*q_prim_vf(momxb + 1)%sf(k - 1, l, q) &
-                                 + 8d0*q_prim_vf(momxb + 1)%sf(k + 1, l, q) &
+                                 - 8._wp*q_prim_vf(momxb + 1)%sf(k - 1, l, q) &
+                                 + 8._wp*q_prim_vf(momxb + 1)%sf(k + 1, l, q) &
                                  - q_prim_vf(momxb + 1)%sf(k + 2, l, q)) &
-                                /(12d0*dx(k))
+                                /(12._wp*dx(k))
                             dv_dy(k, l, q) = &
                                 (q_prim_vf(momxb + 1)%sf(k, l - 2, q) &
-                                 - 8d0*q_prim_vf(momxb + 1)%sf(k, l - 1, q) &
-                                 + 8d0*q_prim_vf(momxb + 1)%sf(k, l + 1, q) &
+                                 - 8._wp*q_prim_vf(momxb + 1)%sf(k, l - 1, q) &
+                                 + 8._wp*q_prim_vf(momxb + 1)%sf(k, l + 1, q) &
                                  - q_prim_vf(momxb + 1)%sf(k, l + 2, q)) &
-                                /(12d0*dy(l))
+                                /(12._wp*dy(l))
                         end do
                     end do
                 end do
@@ -128,34 +128,34 @@ contains
                             do k = 0, m
                                 du_dz(k, l, q) = &
                                     (q_prim_vf(momxb)%sf(k, l, q - 2) &
-                                     - 8d0*q_prim_vf(momxb)%sf(k, l, q - 1) &
-                                     + 8d0*q_prim_vf(momxb)%sf(k, l, q + 1) &
+                                     - 8._wp*q_prim_vf(momxb)%sf(k, l, q - 1) &
+                                     + 8._wp*q_prim_vf(momxb)%sf(k, l, q + 1) &
                                      - q_prim_vf(momxb)%sf(k, l, q + 2)) &
-                                    /(12d0*dz(q))
+                                    /(12._wp*dz(q))
                                 dv_dz(k, l, q) = &
                                     (q_prim_vf(momxb + 1)%sf(k, l, q - 2) &
-                                     - 8d0*q_prim_vf(momxb + 1)%sf(k, l, q - 1) &
-                                     + 8d0*q_prim_vf(momxb + 1)%sf(k, l, q + 1) &
+                                     - 8._wp*q_prim_vf(momxb + 1)%sf(k, l, q - 1) &
+                                     + 8._wp*q_prim_vf(momxb + 1)%sf(k, l, q + 1) &
                                      - q_prim_vf(momxb + 1)%sf(k, l, q + 2)) &
-                                    /(12d0*dz(q))
+                                    /(12._wp*dz(q))
                                 dw_dx(k, l, q) = &
                                     (q_prim_vf(momxe)%sf(k - 2, l, q) &
-                                     - 8d0*q_prim_vf(momxe)%sf(k - 1, l, q) &
-                                     + 8d0*q_prim_vf(momxe)%sf(k + 1, l, q) &
+                                     - 8._wp*q_prim_vf(momxe)%sf(k - 1, l, q) &
+                                     + 8._wp*q_prim_vf(momxe)%sf(k + 1, l, q) &
                                      - q_prim_vf(momxe)%sf(k + 2, l, q)) &
-                                    /(12d0*dx(k))
+                                    /(12._wp*dx(k))
                                 dw_dy(k, l, q) = &
                                     (q_prim_vf(momxe)%sf(k, l - 2, q) &
-                                     - 8d0*q_prim_vf(momxe)%sf(k, l - 1, q) &
-                                     + 8d0*q_prim_vf(momxe)%sf(k, l + 1, q) &
+                                     - 8._wp*q_prim_vf(momxe)%sf(k, l - 1, q) &
+                                     + 8._wp*q_prim_vf(momxe)%sf(k, l + 1, q) &
                                      - q_prim_vf(momxe)%sf(k, l + 2, q)) &
-                                    /(12d0*dy(l))
+                                    /(12._wp*dy(l))
                                 dw_dz(k, l, q) = &
                                     (q_prim_vf(momxe)%sf(k, l, q - 2) &
-                                     - 8d0*q_prim_vf(momxe)%sf(k, l, q - 1) &
-                                     + 8d0*q_prim_vf(momxe)%sf(k, l, q + 1) &
+                                     - 8._wp*q_prim_vf(momxe)%sf(k, l, q - 1) &
+                                     + 8._wp*q_prim_vf(momxe)%sf(k, l, q + 1) &
                                      - q_prim_vf(momxe)%sf(k, l, q + 2)) &
-                                    /(12d0*dz(q))
+                                    /(12._wp*dz(q))
                             end do
                         end do
                     end do
@@ -166,7 +166,7 @@ contains
             do q = 0, p
                 do l = 0, n
                     do k = 0, m
-                        rho_K = 0d0; G_K = 0d0
+                        rho_K = 0._wp; G_K = 0._wp
                         do i = 1, num_fluids
                             rho_K = rho_K + q_prim_vf(i)%sf(k, l, q) !alpha_rho_K(1)
                             G_K = G_K + q_prim_vf(advxb - 1 + i)%sf(k, l, q)*Gs(i)  !alpha_K(1) * Gs(1)
@@ -189,7 +189,7 @@ contains
                     do k = 0, m
                         rhs_vf(strxb)%sf(k, l, q) = &
                             rhs_vf(strxb)%sf(k, l, q) + rho_K_field(k, l, q)* &
-                            ((4d0*G_K_field(k, l, q)/3d0) + &
+                            ((4._wp*G_K_field(k, l, q)/3._wp) + &
                              q_prim_vf(strxb)%sf(k, l, q))* &
                             du_dx(k, l, q)
                     end do
@@ -205,7 +205,7 @@ contains
                                                     (q_prim_vf(strxb + 1)%sf(k, l, q)*du_dy(k, l, q) + &
                                                      q_prim_vf(strxb + 1)%sf(k, l, q)*du_dy(k, l, q) - &
                                                      q_prim_vf(strxb)%sf(k, l, q)*dv_dy(k, l, q) - &
-                                                     2d0*G_K_field(k, l, q)*(1d0/3d0)*dv_dy(k, l, q))
+                                                     2._wp*G_K_field(k, l, q)*(1._wp/3._wp)*dv_dy(k, l, q))
 
                         rhs_vf(strxb + 1)%sf(k, l, q) = rhs_vf(strxb + 1)%sf(k, l, q) + rho_K_field(k, l, q)* &
                                                         (q_prim_vf(strxb + 1)%sf(k, l, q)*du_dx(k, l, q) + &
@@ -214,8 +214,8 @@ contains
                                                          q_prim_vf(strxb + 2)%sf(k, l, q)*du_dy(k, l, q) + &
                                                          q_prim_vf(strxb + 1)%sf(k, l, q)*dv_dy(k, l, q) - &
                                                          q_prim_vf(strxb + 1)%sf(k, l, q)*dv_dy(k, l, q) + &
-                                                         2d0*G_K_field(k, l, q)*(1d0/2d0)*(du_dy(k, l, q) + &
-                                                                                           dv_dx(k, l, q)))
+                                                         2._wp*G_K_field(k, l, q)*(1._wp/2._wp)*(du_dy(k, l, q) + &
+                                                                                                 dv_dx(k, l, q)))
 
                         rhs_vf(strxb + 2)%sf(k, l, q) = rhs_vf(strxb + 2)%sf(k, l, q) + rho_K_field(k, l, q)* &
                                                         (q_prim_vf(strxb + 1)%sf(k, l, q)*dv_dx(k, l, q) + &
@@ -224,9 +224,9 @@ contains
                                                          q_prim_vf(strxb + 2)%sf(k, l, q)*dv_dy(k, l, q) + &
                                                          q_prim_vf(strxb + 2)%sf(k, l, q)*dv_dy(k, l, q) - &
                                                          q_prim_vf(strxb + 2)%sf(k, l, q)*dv_dy(k, l, q) + &
-                                                         2d0*G_K_field(k, l, q)*(dv_dy(k, l, q) - (1d0/3d0)* &
-                                                                                 (du_dx(k, l, q) + &
-                                                                                  dv_dy(k, l, q))))
+                                                         2._wp*G_K_field(k, l, q)*(dv_dy(k, l, q) - (1._wp/3._wp)* &
+                                                                                   (du_dx(k, l, q) + &
+                                                                                    dv_dy(k, l, q))))
                     end do
                 end do
             end do
@@ -240,7 +240,7 @@ contains
                                                     (q_prim_vf(strxb + 3)%sf(k, l, q)*du_dz(k, l, q) + &
                                                      q_prim_vf(strxb + 3)%sf(k, l, q)*du_dz(k, l, q) - &
                                                      q_prim_vf(strxb)%sf(k, l, q)*dw_dz(k, l, q) - &
-                                                     2d0*G_K_field(k, l, q)*(1d0/3d0)*dw_dz(k, l, q))
+                                                     2._wp*G_K_field(k, l, q)*(1._wp/3._wp)*dw_dz(k, l, q))
 
                         rhs_vf(strxb + 1)%sf(k, l, q) = rhs_vf(strxb + 1)%sf(k, l, q) + rho_K_field(k, l, q)* &
                                                         (q_prim_vf(strxb + 4)%sf(k, l, q)*du_dz(k, l, q) + &
@@ -251,7 +251,7 @@ contains
                                                         (q_prim_vf(strxb + 4)%sf(k, l, q)*dv_dz(k, l, q) + &
                                                          q_prim_vf(strxb + 4)%sf(k, l, q)*dv_dz(k, l, q) - &
                                                          q_prim_vf(strxb + 2)%sf(k, l, q)*dw_dz(k, l, q) - &
-                                                         2d0*G_K_field(k, l, q)*(1d0/3d0)*dw_dz(k, l, q))
+                                                         2._wp*G_K_field(k, l, q)*(1._wp/3._wp)*dw_dz(k, l, q))
 
                         rhs_vf(strxb + 3)%sf(k, l, q) = rhs_vf(strxb + 3)%sf(k, l, q) + rho_K_field(k, l, q)* &
                                                         (q_prim_vf(strxb + 3)%sf(k, l, q)*du_dx(k, l, q) + &
@@ -263,8 +263,8 @@ contains
                                                          q_prim_vf(strxb + 5)%sf(k, l, q)*du_dz(k, l, q) + &
                                                          q_prim_vf(strxb + 3)%sf(k, l, q)*dw_dz(k, l, q) - &
                                                          q_prim_vf(strxb + 3)%sf(k, l, q)*dw_dz(k, l, q) + &
-                                                         2d0*G_K_field(k, l, q)*(1d0/2d0)*(du_dz(k, l, q) + &
-                                                                                           dw_dx(k, l, q)))
+                                                         2._wp*G_K_field(k, l, q)*(1._wp/2._wp)*(du_dz(k, l, q) + &
+                                                                                                 dw_dx(k, l, q)))
 
                         rhs_vf(strxb + 4)%sf(k, l, q) = rhs_vf(strxb + 4)%sf(k, l, q) + rho_K_field(k, l, q)* &
                                                         (q_prim_vf(strxb + 3)%sf(k, l, q)*dv_dx(k, l, q) + &
@@ -276,8 +276,8 @@ contains
                                                          q_prim_vf(strxb + 5)%sf(k, l, q)*dv_dz(k, l, q) + &
                                                          q_prim_vf(strxb + 4)%sf(k, l, q)*dw_dz(k, l, q) - &
                                                          q_prim_vf(strxb + 4)%sf(k, l, q)*dw_dz(k, l, q) + &
-                                                         2d0*G_K_field(k, l, q)*(1d0/2d0)*(dv_dz(k, l, q) + &
-                                                                                           dw_dy(k, l, q)))
+                                                         2._wp*G_K_field(k, l, q)*(1._wp/2._wp)*(dv_dz(k, l, q) + &
+                                                                                                 dw_dy(k, l, q)))
 
                         rhs_vf(strxe)%sf(k, l, q) = rhs_vf(strxe)%sf(k, l, q) + rho_K_field(k, l, q)* &
                                                     (q_prim_vf(strxe - 2)%sf(k, l, q)*dw_dx(k, l, q) + &
@@ -289,10 +289,10 @@ contains
                                                      q_prim_vf(strxe)%sf(k, l, q)*dw_dz(k, l, q) + &
                                                      q_prim_vf(strxe)%sf(k, l, q)*dw_dz(k, l, q) - &
                                                      q_prim_vf(strxe)%sf(k, l, q)*dw_dz(k, l, q) + &
-                                                     2d0*G_K_field(k, l, q)*(dw_dz(k, l, q) - (1d0/3d0)* &
-                                                                             (du_dx(k, l, q) + &
-                                                                              dv_dy(k, l, q) + &
-                                                                              dw_dz(k, l, q))))
+                                                     2._wp*G_K_field(k, l, q)*(dw_dz(k, l, q) - (1._wp/3._wp)* &
+                                                                               (du_dx(k, l, q) + &
+                                                                                dv_dy(k, l, q) + &
+                                                                                dw_dz(k, l, q))))
                     end do
                 end do
             end do
diff --git a/src/simulation/m_ibm.fpp b/src/simulation/m_ibm.fpp
index 1790734be..8e6a34e9f 100644
--- a/src/simulation/m_ibm.fpp
+++ b/src/simulation/m_ibm.fpp
@@ -125,31 +125,31 @@ contains
             dimension(sys_size), &
             intent(INOUT) :: q_prim_vf !< Primitive Variables
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), optional, intent(INOUT) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), optional, intent(INOUT) :: pb, mv
 
         integer :: i, j, k, l, q, r!< Iterator variables
         integer :: patch_id !< Patch ID of ghost point
-        real(kind(0d0)) :: rho, gamma, pi_inf, dyn_pres !< Mixture variables
-        real(kind(0d0)), dimension(2) :: Re_K
-        real(kind(0d0)) :: G_K
-        real(kind(0d0)) :: qv_K
-        real(kind(0d0)), dimension(num_fluids) :: Gs
-
-        real(kind(0d0)) :: pres_IP, coeff
-        real(kind(0d0)), dimension(3) :: vel_IP, vel_norm_IP
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho_IP, alpha_IP
-        real(kind(0d0)), dimension(nb) :: r_IP, v_IP, pb_IP, mv_IP
-        real(kind(0d0)), dimension(nb*nmom) :: nmom_IP
-        real(kind(0d0)), dimension(nb*nnode) :: presb_IP, massv_IP
+        real(wp) :: rho, gamma, pi_inf, dyn_pres !< Mixture variables
+        real(wp), dimension(2) :: Re_K
+        real(wp) :: G_K
+        real(wp) :: qv_K
+        real(wp), dimension(num_fluids) :: Gs
+
+        real(wp) :: pres_IP, coeff
+        real(wp), dimension(3) :: vel_IP, vel_norm_IP
+        real(wp), dimension(num_fluids) :: alpha_rho_IP, alpha_IP
+        real(wp), dimension(nb) :: r_IP, v_IP, pb_IP, mv_IP
+        real(wp), dimension(nb*nmom) :: nmom_IP
+        real(wp), dimension(nb*nnode) :: presb_IP, massv_IP
         !! Primitive variables at the image point associated with a ghost point,
         !! interpolated from surrounding fluid cells.
 
-        real(kind(0d0)), dimension(3) :: norm !< Normal vector from GP to IP
-        real(kind(0d0)), dimension(3) :: physical_loc !< Physical loc of GP
-        real(kind(0d0)), dimension(3) :: vel_g !< Velocity of GP
+        real(wp), dimension(3) :: norm !< Normal vector from GP to IP
+        real(wp), dimension(3) :: physical_loc !< Physical loc of GP
+        real(wp), dimension(3) :: vel_g !< Velocity of GP
 
-        real(kind(0d0)) :: nbub
-        real(kind(0d0)) :: buf
+        real(wp) :: nbub
+        real(wp) :: buf
         type(ghost_point) :: gp
         type(ghost_point) :: innerp
 
@@ -166,7 +166,7 @@ contains
             if (p > 0) then
                 physical_loc = [x_cc(j), y_cc(k), z_cc(l)]
             else
-                physical_loc = [x_cc(j), y_cc(k), 0d0]
+                physical_loc = [x_cc(j), y_cc(k), 0._wp]
             end if
 
             !Interpolate primitive variables at image point associated w/ GP
@@ -187,7 +187,7 @@ contains
                                                alpha_rho_IP, alpha_IP, pres_IP, vel_IP)
             end if
 
-            dyn_pres = 0d0
+            dyn_pres = 0._wp
 
             ! Set q_prim_vf params at GP so that mixture vars calculated properly
             !$acc loop seq
@@ -216,7 +216,7 @@ contains
                 vel_norm_IP = sum(vel_IP*norm)*norm
                 vel_g = vel_IP - vel_norm_IP
             else
-                vel_g = 0d0
+                vel_g = 0._wp
             end if
 
             ! Set momentum
@@ -224,7 +224,7 @@ contains
             do q = momxb, momxe
                 q_cons_vf(q)%sf(j, k, l) = rho*vel_g(q - momxb + 1)
                 dyn_pres = dyn_pres + q_cons_vf(q)%sf(j, k, l)* &
-                           vel_g(q - momxb + 1)/2d0
+                           vel_g(q - momxb + 1)/2._wp
             end do
 
             ! Set continuity and adv vars
@@ -289,7 +289,7 @@ contains
         !$acc parallel loop gang vector private(physical_loc, dyn_pres, alpha_rho_IP, alpha_IP, vel_g, rho, gamma, pi_inf, Re_K, innerp, j, k, l, q)
         do i = 1, num_inner_gps
 
-            vel_g = 0d0
+            vel_g = 0._wp
             innerp = inner_points(i)
             j = innerp%loc(1)
             k = innerp%loc(2)
@@ -300,7 +300,7 @@ contains
             if (p > 0) then
                 physical_loc = [x_cc(j), y_cc(k), z_cc(l)]
             else
-                physical_loc = [x_cc(j), y_cc(k), 0d0]
+                physical_loc = [x_cc(j), y_cc(k), 0._wp]
             end if
 
             !$acc loop seq
@@ -312,13 +312,13 @@ contains
             call s_convert_species_to_mixture_variables_acc(rho, gamma, pi_inf, qv_K, alpha_IP, &
                                                             alpha_rho_IP, Re_K, j, k, l)
 
-            dyn_pres = 0d0
+            dyn_pres = 0._wp
 
             !$acc loop seq
             do q = momxb, momxe
                 q_cons_vf(q)%sf(j, k, l) = rho*vel_g(q - momxb + 1)
                 dyn_pres = dyn_pres + q_cons_vf(q)%sf(j, k, l)* &
-                           vel_g(q - momxb + 1)/2d0
+                           vel_g(q - momxb + 1)/2._wp
             end do
         end do
 
@@ -334,11 +334,11 @@ contains
         type(levelset_field), intent(IN) :: levelset
         type(levelset_norm_field), intent(IN) :: levelset_norm
 
-        real(kind(0d0)) :: dist
-        real(kind(0d0)), dimension(3) :: norm
-        real(kind(0d0)), dimension(3) :: physical_loc
-        real(kind(0d0)) :: temp_loc
-        real(kind(0d0)), pointer, dimension(:) :: s_cc => null()
+        real(wp) :: dist
+        real(wp), dimension(3) :: norm
+        real(wp), dimension(3) :: physical_loc
+        real(wp) :: temp_loc
+        real(wp), pointer, dimension(:) :: s_cc => null()
         integer :: bound
         type(ghost_point) :: gp
 
@@ -358,7 +358,7 @@ contains
             if (p > 0) then
                 physical_loc = [x_cc(i), y_cc(j), z_cc(k)]
             else
-                physical_loc = [x_cc(i), y_cc(j), 0d0]
+                physical_loc = [x_cc(i), y_cc(j), 0._wp]
             end if
 
             ! Calculate and store the precise location of the image point
@@ -599,11 +599,11 @@ contains
 
         type(ghost_point), dimension(num_gps), intent(INOUT) :: ghost_points
 
-        real(kind(0d0)), dimension(2, 2, 2) :: dist
-        real(kind(0d0)), dimension(2, 2, 2) :: alpha
-        real(kind(0d0)), dimension(2, 2, 2) :: interp_coeffs
-        real(kind(0d0)) :: buf
-        real(kind(0d0)), dimension(2, 2, 2) :: eta
+        real(wp), dimension(2, 2, 2) :: dist
+        real(wp), dimension(2, 2, 2) :: alpha
+        real(wp), dimension(2, 2, 2) :: interp_coeffs
+        real(wp) :: buf
+        real(wp), dimension(2, 2, 2) :: eta
         type(ghost_point) :: gp
         integer :: i, j, k, l, q !< Iterator variables
         integer :: i1, i2, j1, j2, k1, k2 !< Grid indexes
@@ -617,8 +617,8 @@ contains
                 i1 = gp%ip_grid(1); i2 = i1 + 1
                 j1 = gp%ip_grid(2); j2 = j1 + 1
 
-                dist = 0d0
-                buf = 1d0
+                dist = 0._wp
+                buf = 1._wp
                 dist(1, 1, 1) = sqrt( &
                                 (x_cc(i1) - gp%ip_loc(1))**2 + &
                                 (y_cc(j1) - gp%ip_loc(2))**2)
@@ -632,26 +632,26 @@ contains
                                 (x_cc(i2) - gp%ip_loc(1))**2 + &
                                 (y_cc(j2) - gp%ip_loc(2))**2)
 
-                interp_coeffs = 0d0
+                interp_coeffs = 0._wp
 
-                if (dist(1, 1, 1) <= 1d-16) then
-                    interp_coeffs(1, 1, 1) = 1d0
-                else if (dist(2, 1, 1) <= 1d-16) then
-                    interp_coeffs(2, 1, 1) = 1d0
-                else if (dist(1, 2, 1) <= 1d-16) then
-                    interp_coeffs(1, 2, 1) = 1d0
-                else if (dist(2, 2, 1) <= 1d-16) then
-                    interp_coeffs(2, 2, 1) = 1d0
+                if (dist(1, 1, 1) <= 1e-16_wp) then
+                    interp_coeffs(1, 1, 1) = 1._wp
+                else if (dist(2, 1, 1) <= 1e-16_wp) then
+                    interp_coeffs(2, 1, 1) = 1._wp
+                else if (dist(1, 2, 1) <= 1e-16_wp) then
+                    interp_coeffs(1, 2, 1) = 1._wp
+                else if (dist(2, 2, 1) <= 1e-16_wp) then
+                    interp_coeffs(2, 2, 1) = 1._wp
                 else
-                    eta(:, :, 1) = 1d0/dist(:, :, 1)**2
-                    alpha = 1d0
+                    eta(:, :, 1) = 1._wp/dist(:, :, 1)**2
+                    alpha = 1._wp
                     patch_id = gp%ib_patch_id
-                    if (ib_markers%sf(i1, j1, 0) /= 0) alpha(1, 1, 1) = 0d0
-                    if (ib_markers%sf(i2, j1, 0) /= 0) alpha(2, 1, 1) = 0d0
-                    if (ib_markers%sf(i1, j2, 0) /= 0) alpha(1, 2, 1) = 0d0
-                    if (ib_markers%sf(i2, j2, 0) /= 0) alpha(2, 2, 1) = 0d0
+                    if (ib_markers%sf(i1, j1, 0) /= 0) alpha(1, 1, 1) = 0._wp
+                    if (ib_markers%sf(i2, j1, 0) /= 0) alpha(2, 1, 1) = 0._wp
+                    if (ib_markers%sf(i1, j2, 0) /= 0) alpha(1, 2, 1) = 0._wp
+                    if (ib_markers%sf(i2, j2, 0) /= 0) alpha(2, 2, 1) = 0._wp
                     buf = sum(alpha(:, :, 1)*eta(:, :, 1))
-                    if (buf > 0d0) then
+                    if (buf > 0._wp) then
                         interp_coeffs(:, :, 1) = alpha(:, :, 1)*eta(:, :, 1)/buf
                     else
                         buf = sum(eta(:, :, 1))
@@ -703,37 +703,37 @@ contains
                                 (x_cc(i2) - gp%ip_loc(1))**2 + &
                                 (y_cc(j2) - gp%ip_loc(2))**2 + &
                                 (z_cc(k2) - gp%ip_loc(3))**2)
-                interp_coeffs = 0d0
-                buf = 1d0
-                if (dist(1, 1, 1) <= 1d-16) then
-                    interp_coeffs(1, 1, 1) = 1d0
-                else if (dist(2, 1, 1) <= 1d-16) then
-                    interp_coeffs(2, 1, 1) = 1d0
-                else if (dist(1, 2, 1) <= 1d-16) then
-                    interp_coeffs(1, 2, 1) = 1d0
-                else if (dist(2, 2, 1) <= 1d-16) then
-                    interp_coeffs(2, 2, 1) = 1d0
-                else if (dist(1, 1, 2) <= 1d-16) then
-                    interp_coeffs(1, 1, 2) = 1d0
-                else if (dist(2, 1, 2) <= 1d-16) then
-                    interp_coeffs(2, 1, 2) = 1d0
-                else if (dist(1, 2, 2) <= 1d-16) then
-                    interp_coeffs(1, 2, 2) = 1d0
-                else if (dist(2, 2, 2) <= 1d-16) then
-                    interp_coeffs(2, 2, 2) = 1d0
+                interp_coeffs = 0._wp
+                buf = 1._wp
+                if (dist(1, 1, 1) <= 1e-16_wp) then
+                    interp_coeffs(1, 1, 1) = 1._wp
+                else if (dist(2, 1, 1) <= 1e-16_wp) then
+                    interp_coeffs(2, 1, 1) = 1._wp
+                else if (dist(1, 2, 1) <= 1e-16_wp) then
+                    interp_coeffs(1, 2, 1) = 1._wp
+                else if (dist(2, 2, 1) <= 1e-16_wp) then
+                    interp_coeffs(2, 2, 1) = 1._wp
+                else if (dist(1, 1, 2) <= 1e-16_wp) then
+                    interp_coeffs(1, 1, 2) = 1._wp
+                else if (dist(2, 1, 2) <= 1e-16_wp) then
+                    interp_coeffs(2, 1, 2) = 1._wp
+                else if (dist(1, 2, 2) <= 1e-16_wp) then
+                    interp_coeffs(1, 2, 2) = 1._wp
+                else if (dist(2, 2, 2) <= 1e-16_wp) then
+                    interp_coeffs(2, 2, 2) = 1._wp
                 else
-                    eta = 1d0/dist**2
-                    alpha = 1d0
-                    if (ib_markers%sf(i1, j1, k1) /= 0) alpha(1, 1, 1) = 0d0
-                    if (ib_markers%sf(i2, j1, k1) /= 0) alpha(2, 1, 1) = 0d0
-                    if (ib_markers%sf(i1, j2, k1) /= 0) alpha(1, 2, 1) = 0d0
-                    if (ib_markers%sf(i2, j2, k1) /= 0) alpha(2, 2, 1) = 0d0
-                    if (ib_markers%sf(i1, j1, k2) /= 0) alpha(1, 1, 2) = 0d0
-                    if (ib_markers%sf(i2, j1, k2) /= 0) alpha(2, 1, 2) = 0d0
-                    if (ib_markers%sf(i1, j2, k2) /= 0) alpha(1, 2, 2) = 0d0
-                    if (ib_markers%sf(i2, j2, k2) /= 0) alpha(2, 2, 2) = 0d0
+                    eta = 1._wp/dist**2
+                    alpha = 1._wp
+                    if (ib_markers%sf(i1, j1, k1) /= 0) alpha(1, 1, 1) = 0._wp
+                    if (ib_markers%sf(i2, j1, k1) /= 0) alpha(2, 1, 1) = 0._wp
+                    if (ib_markers%sf(i1, j2, k1) /= 0) alpha(1, 2, 1) = 0._wp
+                    if (ib_markers%sf(i2, j2, k1) /= 0) alpha(2, 2, 1) = 0._wp
+                    if (ib_markers%sf(i1, j1, k2) /= 0) alpha(1, 1, 2) = 0._wp
+                    if (ib_markers%sf(i2, j1, k2) /= 0) alpha(2, 1, 2) = 0._wp
+                    if (ib_markers%sf(i1, j2, k2) /= 0) alpha(1, 2, 2) = 0._wp
+                    if (ib_markers%sf(i2, j2, k2) /= 0) alpha(2, 2, 2) = 0._wp
                     buf = sum(alpha*eta)
-                    if (buf > 0d0) then
+                    if (buf > 0._wp) then
                         interp_coeffs = alpha*eta/buf
                     else
                         buf = sum(eta)
@@ -754,19 +754,19 @@ contains
         type(scalar_field), &
             dimension(sys_size), &
             intent(IN) :: q_prim_vf !< Primitive Variables
-        real(kind(0d0)), optional, dimension(startx:, starty:, startz:, 1:, 1:), intent(INOUT) :: pb, mv
+        real(wp), optional, dimension(startx:, starty:, startz:, 1:, 1:), intent(INOUT) :: pb, mv
 
         type(ghost_point), intent(IN) :: gp
-        real(kind(0d0)), intent(INOUT) :: pres_IP
-        real(kind(0d0)), dimension(3), intent(INOUT) :: vel_IP
-        real(kind(0d0)), dimension(num_fluids), intent(INOUT) :: alpha_IP, alpha_rho_IP
-        real(kind(0d0)), optional, dimension(:), intent(INOUT) :: r_IP, v_IP, pb_IP, mv_IP
-        real(kind(0d0)), optional, dimension(:), intent(INOUT) :: nmom_IP
-        real(kind(0d0)), optional, dimension(:), intent(INOUT) :: presb_IP, massv_IP
+        real(wp), intent(INOUT) :: pres_IP
+        real(wp), dimension(3), intent(INOUT) :: vel_IP
+        real(wp), dimension(num_fluids), intent(INOUT) :: alpha_IP, alpha_rho_IP
+        real(wp), optional, dimension(:), intent(INOUT) :: r_IP, v_IP, pb_IP, mv_IP
+        real(wp), optional, dimension(:), intent(INOUT) :: nmom_IP
+        real(wp), optional, dimension(:), intent(INOUT) :: presb_IP, massv_IP
 
         integer :: i, j, k, l, q !< Iterator variables
         integer :: i1, i2, j1, j2, k1, k2 !< Iterator variables
-        real(kind(0d0)) :: coeff
+        real(wp) :: coeff
 
         i1 = gp%ip_grid(1); i2 = i1 + 1
         j1 = gp%ip_grid(2); j2 = j1 + 1
@@ -777,25 +777,25 @@ contains
             k2 = 0
         end if
 
-        alpha_rho_IP = 0d0
-        alpha_IP = 0d0
-        pres_IP = 0d0
-        vel_IP = 0d0
+        alpha_rho_IP = 0._wp
+        alpha_IP = 0._wp
+        pres_IP = 0._wp
+        vel_IP = 0._wp
 
         if (bubbles) then
-            r_IP = 0d0
-            v_IP = 0d0
+            r_IP = 0._wp
+            v_IP = 0._wp
             if (.not. polytropic) then
-                mv_IP = 0d0
-                pb_IP = 0d0
+                mv_IP = 0._wp
+                pb_IP = 0._wp
             end if
         end if
 
         if (qbmm) then
-            nmom_IP = 0d0
+            nmom_IP = 0._wp
             if (.not. polytropic) then
-                presb_IP = 0d0
-                massv_IP = 0d0
+                presb_IP = 0._wp
+                massv_IP = 0._wp
             end if
         end if
 
diff --git a/src/simulation/m_mpi_proxy.fpp b/src/simulation/m_mpi_proxy.fpp
index 8b1ea7749..b57701cd7 100644
--- a/src/simulation/m_mpi_proxy.fpp
+++ b/src/simulation/m_mpi_proxy.fpp
@@ -34,22 +34,22 @@ module m_mpi_proxy
 
     implicit none
 
-    real(kind(0d0)), private, allocatable, dimension(:), target :: q_cons_buff_send !<
+    real(wp), private, allocatable, dimension(:), target :: q_cons_buff_send !<
     !! This variable is utilized to pack and send the buffer of the cell-average
     !! conservative variables, for a single computational domain boundary at the
     !! time, to the relevant neighboring processor.
 
-    real(kind(0d0)), private, allocatable, dimension(:), target :: q_cons_buff_recv !<
+    real(wp), private, allocatable, dimension(:), target :: q_cons_buff_recv !<
     !! q_cons_buff_recv is utilized to receive and unpack the buffer of the cell-
     !! average conservative variables, for a single computational domain boundary
     !! at the time, from the relevant neighboring processor.
 
-    real(kind(0d0)), private, allocatable, dimension(:), target :: c_divs_buff_send !<
+    real(wp), private, allocatable, dimension(:), target :: c_divs_buff_send !<
     !! c_divs_buff_send is utilized to send and unpack the buffer of the cell-
     !! centered color function derivatives, for a single computational domain
     !! boundary at the time, to the the relevant neighboring processor
 
-    real(kind(0d0)), private, allocatable, dimension(:), target :: c_divs_buff_recv
+    real(wp), private, allocatable, dimension(:), target :: c_divs_buff_recv
     !! c_divs_buff_recv is utilized to receiver and unpack the buffer of the cell-
     !! centered color function derivatives, for a single computational domain
     !! boundary at the time, from the relevant neighboring processor
@@ -74,10 +74,6 @@ module m_mpi_proxy
     !> @}
     !$acc declare create(v_size)
 
-    !real :: s_time, e_time
-    !real :: compress_time, mpi_time, decompress_time
-    !integer :: nCalls_time = 0
-
     integer :: nVars !< nVars for surface tension communication
     !$acc declare create(nVars)
 
@@ -174,7 +170,7 @@ contains
 
         #:for VAR in ['k_x', 'k_y', 'k_z', 'w_x', 'w_y', 'w_z', 'p_x', 'p_y', &
             & 'p_z', 'g_x', 'g_y', 'g_z']
-            call MPI_BCAST(${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
         #:endfor
 
         #:for VAR in ['t_step_old', 'm', 'n', 'p', 'm_glb', 'n_glb', 'p_glb',  &
@@ -220,7 +216,7 @@ contains
             & 'bc_x%pres_in','bc_x%pres_out','bc_y%pres_in','bc_y%pres_out', 'bc_z%pres_in','bc_z%pres_out', &
             & 'x_domain%beg', 'x_domain%end', 'y_domain%beg', 'y_domain%end',    &
             & 'z_domain%beg', 'z_domain%end', 't_stop',  't_save', 'cfl_target']
-            call MPI_BCAST(${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
         #:endfor
 
         do i = 1, 3
@@ -237,15 +233,15 @@ contains
             call MPI_BCAST(weno_order, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, ierr)
             call MPI_BCAST(nb, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, ierr)
             call MPI_BCAST(num_fluids, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, ierr)
-            call MPI_BCAST(wenoz_q, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(wenoz_q, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
         #:endif
 
         do i = 1, num_fluids_max
             #:for VAR in [ 'gamma','pi_inf','mul0','ss','pv','gamma_v','M_v',  &
                 & 'mu_v','k_v','G', 'cv', 'qv', 'qvp' ]
-                call MPI_BCAST(fluid_pp(i)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(fluid_pp(i)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
-            call MPI_BCAST(fluid_pp(i)%Re(1), 2, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+            call MPI_BCAST(fluid_pp(i)%Re(1), 2, mpi_p, 0, MPI_COMM_WORLD, ierr)
         end do
 
         do i = 1, num_fluids_max
@@ -257,14 +253,14 @@ contains
         do i = 1, num_ibs
             #:for VAR in [ 'radius', 'length_x', 'length_y', &
                 & 'x_centroid', 'y_centroid', 'c', 'm', 'p', 't', 'theta', 'slip' ]
-                call MPI_BCAST(patch_ib(i)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(patch_ib(i)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
             call MPI_BCAST(patch_ib(i)%geometry, 2, MPI_INTEGER, 0, MPI_COMM_WORLD, ierr)
         end do
 
         do j = 1, num_probes_max
             do i = 1, 3
-                call MPI_BCAST(acoustic(j)%loc(i), 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(acoustic(j)%loc(i), 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             end do
 
             call MPI_BCAST(acoustic(j)%dipole, 1, MPI_LOGICAL, 0, MPI_COMM_WORLD, ierr)
@@ -278,15 +274,15 @@ contains
                 'npulse', 'dir', 'delay', 'foc_length', 'aperture', &
                 'element_spacing_angle', 'element_polygon_ratio', 'rotate_angle', &
                 'bb_bandwidth', 'bb_lowest_freq' ]
-                call MPI_BCAST(acoustic(j)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(acoustic(j)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
 
             #:for VAR in [ 'x','y','z' ]
-                call MPI_BCAST(probe(j)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(probe(j)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
 
             #:for VAR in [ 'xmin', 'xmax', 'ymin', 'ymax', 'zmin', 'zmax' ]
-                call MPI_BCAST(integral(j)%${VAR}$, 1, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+                call MPI_BCAST(integral(j)%${VAR}$, 1, mpi_p, 0, MPI_COMM_WORLD, ierr)
             #:endfor
         end do
 
@@ -307,10 +303,10 @@ contains
         integer :: num_procs_x, num_procs_y, num_procs_z !<
             !! Optimal number of processors in the x-, y- and z-directions
 
-        real(kind(0d0)) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z !<
+        real(wp) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z !<
             !! Non-optimal number of processors in the x-, y- and z-directions
 
-        real(kind(0d0)) :: fct_min !<
+        real(wp) :: fct_min !<
             !! Processor factorization (fct) minimization parameter
 
         integer :: MPI_COMM_CART !<
@@ -349,8 +345,8 @@ contains
                     tmp_num_procs_x = num_procs_x
                     tmp_num_procs_y = num_procs_y
                     tmp_num_procs_z = num_procs_z
-                    fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                       - (n + 1)/tmp_num_procs_y)
+                    fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                         - (n + 1)/tmp_num_procs_y)
 
                     ! Searching for optimal computational domain distribution
                     do i = 1, num_procs
@@ -393,10 +389,10 @@ contains
                     tmp_num_procs_x = num_procs_x
                     tmp_num_procs_y = num_procs_y
                     tmp_num_procs_z = num_procs_z
-                    fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                       - (n + 1)/tmp_num_procs_y) &
-                              + 10d0*abs((n + 1)/tmp_num_procs_y &
-                                         - (p + 1)/tmp_num_procs_z)
+                    fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                         - (n + 1)/tmp_num_procs_y) &
+                              + 10._wp*abs((n + 1)/tmp_num_procs_y &
+                                           - (p + 1)/tmp_num_procs_z)
 
                     ! Optimization of the initial processor topology
                     do i = 1, num_procs
@@ -516,8 +512,8 @@ contains
                 ! Benchmarking the quality of this initial guess
                 tmp_num_procs_x = num_procs_x
                 tmp_num_procs_y = num_procs_y
-                fct_min = 10d0*abs((m + 1)/tmp_num_procs_x &
-                                   - (n + 1)/tmp_num_procs_y)
+                fct_min = 10._wp*abs((m + 1)/tmp_num_procs_x &
+                                     - (n + 1)/tmp_num_procs_y)
 
                 ! Optimization of the initial processor topology
                 do i = 1, num_procs
@@ -697,9 +693,9 @@ contains
                     ! Send/receive buffer to/from bc_x%end/bc_x%beg
                     call MPI_SENDRECV( &
                         dx(m - buff_size + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%end, 0, &
+                        mpi_p, bc_x%end, 0, &
                         dx(-buff_size), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%beg, 0, &
+                        mpi_p, bc_x%beg, 0, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 else                        ! PBC at the beginning only
@@ -707,9 +703,9 @@ contains
                     ! Send/receive buffer to/from bc_x%beg/bc_x%beg
                     call MPI_SENDRECV( &
                         dx(0), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%beg, 1, &
+                        mpi_p, bc_x%beg, 1, &
                         dx(-buff_size), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%beg, 0, &
+                        mpi_p, bc_x%beg, 0, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 end if
@@ -721,9 +717,9 @@ contains
                     ! Send/receive buffer to/from bc_x%beg/bc_x%end
                     call MPI_SENDRECV( &
                         dx(0), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%beg, 1, &
+                        mpi_p, bc_x%beg, 1, &
                         dx(m + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%end, 1, &
+                        mpi_p, bc_x%end, 1, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 else                        ! PBC at the end only
@@ -731,9 +727,9 @@ contains
                     ! Send/receive buffer to/from bc_x%end/bc_x%end
                     call MPI_SENDRECV( &
                         dx(m - buff_size + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%end, 0, &
+                        mpi_p, bc_x%end, 0, &
                         dx(m + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_x%end, 1, &
+                        mpi_p, bc_x%end, 1, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 end if
@@ -751,9 +747,9 @@ contains
                     ! Send/receive buffer to/from bc_y%end/bc_y%beg
                     call MPI_SENDRECV( &
                         dy(n - buff_size + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%end, 0, &
+                        mpi_p, bc_y%end, 0, &
                         dy(-buff_size), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%beg, 0, &
+                        mpi_p, bc_y%beg, 0, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 else                        ! PBC at the beginning only
@@ -761,9 +757,9 @@ contains
                     ! Send/receive buffer to/from bc_y%beg/bc_y%beg
                     call MPI_SENDRECV( &
                         dy(0), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%beg, 1, &
+                        mpi_p, bc_y%beg, 1, &
                         dy(-buff_size), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%beg, 0, &
+                        mpi_p, bc_y%beg, 0, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 end if
@@ -775,9 +771,9 @@ contains
                     ! Send/receive buffer to/from bc_y%beg/bc_y%end
                     call MPI_SENDRECV( &
                         dy(0), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%beg, 1, &
+                        mpi_p, bc_y%beg, 1, &
                         dy(n + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%end, 1, &
+                        mpi_p, bc_y%end, 1, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 else                        ! PBC at the end only
@@ -785,9 +781,9 @@ contains
                     ! Send/receive buffer to/from bc_y%end/bc_y%end
                     call MPI_SENDRECV( &
                         dy(n - buff_size + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%end, 0, &
+                        mpi_p, bc_y%end, 0, &
                         dy(n + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_y%end, 1, &
+                        mpi_p, bc_y%end, 1, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 end if
@@ -805,9 +801,9 @@ contains
                     ! Send/receive buffer to/from bc_z%end/bc_z%beg
                     call MPI_SENDRECV( &
                         dz(p - buff_size + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%end, 0, &
+                        mpi_p, bc_z%end, 0, &
                         dz(-buff_size), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%beg, 0, &
+                        mpi_p, bc_z%beg, 0, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 else                        ! PBC at the beginning only
@@ -815,9 +811,9 @@ contains
                     ! Send/receive buffer to/from bc_z%beg/bc_z%beg
                     call MPI_SENDRECV( &
                         dz(0), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%beg, 1, &
+                        mpi_p, bc_z%beg, 1, &
                         dz(-buff_size), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%beg, 0, &
+                        mpi_p, bc_z%beg, 0, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 end if
@@ -829,9 +825,9 @@ contains
                     ! Send/receive buffer to/from bc_z%beg/bc_z%end
                     call MPI_SENDRECV( &
                         dz(0), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%beg, 1, &
+                        mpi_p, bc_z%beg, 1, &
                         dz(p + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%end, 1, &
+                        mpi_p, bc_z%end, 1, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 else                        ! PBC at the end only
@@ -839,9 +835,9 @@ contains
                     ! Send/receive buffer to/from bc_z%end/bc_z%end
                     call MPI_SENDRECV( &
                         dz(p - buff_size + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%end, 0, &
+                        mpi_p, bc_z%end, 0, &
                         dz(p + 1), buff_size, &
-                        MPI_DOUBLE_PRECISION, bc_z%end, 1, &
+                        mpi_p, bc_z%end, 1, &
                         MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 end if
@@ -867,7 +863,7 @@ contains
                                                 pbc_loc)
 
         type(scalar_field), dimension(sys_size), intent(inout) :: q_cons_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, mv
         integer, intent(in) :: mpi_dir, pbc_loc
 
         integer :: i, j, k, l, r, q !< Generic loop iterators
@@ -881,7 +877,8 @@ contains
         logical :: beg_end_geq_0
 
         integer :: pack_offset, unpack_offset
-        real(kind(0d0)), pointer :: p_send, p_recv
+
+        real(wp), pointer :: p_send, p_recv
 
 #ifdef MFC_MPI
 
@@ -1097,8 +1094,8 @@ contains
                 #:endif
 
                 call MPI_SENDRECV( &
-                    p_send, buffer_count, MPI_DOUBLE_PRECISION, dst_proc, send_tag, &
-                    p_recv, buffer_count, MPI_DOUBLE_PRECISION, src_proc, recv_tag, &
+                    p_send, buffer_count, mpi_p, dst_proc, send_tag, &
+                    p_recv, buffer_count, mpi_p, src_proc, recv_tag, &
                     MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
                 call nvtxEndRange ! RHS-MPI-SENDRECV-(NO)-RDMA
 
@@ -2155,7 +2152,7 @@ contains
         logical :: beg_end_geq_0
 
         integer :: pack_offset, unpack_offset
-        real(kind(0d0)), pointer :: p_send, p_recv
+        real(wp), pointer :: p_send, p_recv
 
 #ifdef MFC_MPI
 
@@ -2261,8 +2258,8 @@ contains
                 #:endif
 
                 call MPI_SENDRECV( &
-                    p_send, buffer_count, MPI_DOUBLE_PRECISION, dst_proc, send_tag, &
-                    p_recv, buffer_count, MPI_DOUBLE_PRECISION, src_proc, recv_tag, &
+                    p_send, buffer_count, mpi_p, dst_proc, send_tag, &
+                    p_recv, buffer_count, mpi_p, src_proc, recv_tag, &
                     MPI_COMM_WORLD, MPI_STATUS_IGNORE, ierr)
 
                 #:if rdma_mpi
@@ -2352,9 +2349,9 @@ contains
 
     subroutine s_mpi_send_random_number(phi_rn, num_freq)
         integer, intent(in) :: num_freq
-        real(kind(0d0)), intent(inout), dimension(1:num_freq) :: phi_rn
+        real(wp), intent(inout), dimension(1:num_freq) :: phi_rn
 #ifdef MFC_MPI
-        call MPI_BCAST(phi_rn, num_freq, MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
+        call MPI_BCAST(phi_rn, num_freq, mpi_p, 0, MPI_COMM_WORLD, ierr)
 #endif
     end subroutine s_mpi_send_random_number
 
diff --git a/src/simulation/m_qbmm.fpp b/src/simulation/m_qbmm.fpp
index b22163b21..457084934 100644
--- a/src/simulation/m_qbmm.fpp
+++ b/src/simulation/m_qbmm.fpp
@@ -28,7 +28,7 @@ module m_qbmm
 
     private; public :: s_initialize_qbmm_module, s_mom_inv, s_coeff, s_compute_qbmm_rhs
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :, :) :: momrhs
+    real(wp), allocatable, dimension(:, :, :, :, :) :: momrhs
     !$acc declare create(momrhs)
 
     #:if MFC_CASE_OPTIMIZATION
@@ -67,7 +67,7 @@ contains
         #:endif
 
         @:ALLOCATE(momrhs(1:3, 0:2, 0:2, 1:nterms, 1:nb))
-        momrhs = 0d0
+        momrhs = 0._wp
 
         ! Assigns the required RHS moments for moment transport equations
         ! The rhs%(:,3) is only to be used for R0 quadrature, not for computing X/Y indices
@@ -77,169 +77,169 @@ contains
                 do i1 = 0, 2; do i2 = 0, 2
                         if ((i1 + i2) <= 2) then
                             if (bubble_model == 3) then
-                                momrhs(1, i1, i2, 1, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 1, q) = -1.d0 + i2
-                                momrhs(3, i1, i2, 1, q) = 0d0
+                                momrhs(1, i1, i2, 1, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 1, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 1, q) = 0._wp
 
-                                momrhs(1, i1, i2, 2, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 2, q) = 1.d0 + i2
-                                momrhs(3, i1, i2, 2, q) = 0d0
+                                momrhs(1, i1, i2, 2, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 2, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 2, q) = 0._wp
 
-                                momrhs(1, i1, i2, 3, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 3, q) = -1.d0 + i2
-                                momrhs(3, i1, i2, 3, q) = 0d0
+                                momrhs(1, i1, i2, 3, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 3, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 3, q) = 0._wp
 
-                                momrhs(1, i1, i2, 4, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 4, q) = 1.d0 + i2
-                                momrhs(3, i1, i2, 4, q) = 0d0
+                                momrhs(1, i1, i2, 4, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 4, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 4, q) = 0._wp
 
                                 if (.not. f_is_default(Re_inv)) then
                                     ! add viscosity
-                                    momrhs(1, i1, i2, 5, q) = -2.d0 + i1
+                                    momrhs(1, i1, i2, 5, q) = -2._wp + i1
                                     momrhs(2, i1, i2, 5, q) = i2
-                                    momrhs(3, i1, i2, 5, q) = 0d0
+                                    momrhs(3, i1, i2, 5, q) = 0._wp
                                 end if
 
                                 if (.not. f_is_default(Web)) then
                                     ! add surface tension
-                                    momrhs(1, i1, i2, 6, q) = -2.d0 + i1
-                                    momrhs(2, i1, i2, 6, q) = -1.d0 + i2
-                                    momrhs(3, i1, i2, 6, q) = 0d0
+                                    momrhs(1, i1, i2, 6, q) = -2._wp + i1
+                                    momrhs(2, i1, i2, 6, q) = -1._wp + i2
+                                    momrhs(3, i1, i2, 6, q) = 0._wp
                                 end if
 
-                                momrhs(1, i1, i2, 7, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 7, q) = -1.d0 + i2
-                                momrhs(3, i1, i2, 7, q) = 0d0
+                                momrhs(1, i1, i2, 7, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 7, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 7, q) = 0._wp
 
                             else if (bubble_model == 2) then
                                 ! KM with approximation of 1/(1-V/C) = 1+V/C
-                                momrhs(1, i1, i2, 1, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 1, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 1, q) = 0d0
+                                momrhs(1, i1, i2, 1, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 1, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 1, q) = 0._wp
 
-                                momrhs(1, i1, i2, 2, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 2, q) = 2d0 + i2
-                                momrhs(3, i1, i2, 2, q) = 0d0
+                                momrhs(1, i1, i2, 2, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 2, q) = 2._wp + i2
+                                momrhs(3, i1, i2, 2, q) = 0._wp
 
-                                momrhs(1, i1, i2, 3, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 3, q) = 3d0 + i2
-                                momrhs(3, i1, i2, 3, q) = 0d0
+                                momrhs(1, i1, i2, 3, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 3, q) = 3._wp + i2
+                                momrhs(3, i1, i2, 3, q) = 0._wp
 
-                                momrhs(1, i1, i2, 4, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 4, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 4, q) = 0d0
+                                momrhs(1, i1, i2, 4, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 4, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 4, q) = 0._wp
 
-                                momrhs(1, i1, i2, 5, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 5, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 5, q) = i2
-                                momrhs(3, i1, i2, 5, q) = 0d0
+                                momrhs(3, i1, i2, 5, q) = 0._wp
 
-                                momrhs(1, i1, i2, 6, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 6, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 6, q) = 0d0
+                                momrhs(1, i1, i2, 6, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 6, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 6, q) = 0._wp
 
-                                momrhs(1, i1, i2, 7, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 7, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 7, q) = 0d0
+                                momrhs(1, i1, i2, 7, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 7, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 7, q) = 0._wp
 
-                                momrhs(1, i1, i2, 8, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 8, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 8, q) = i2
-                                momrhs(3, i1, i2, 8, q) = 0d0
+                                momrhs(3, i1, i2, 8, q) = 0._wp
 
-                                momrhs(1, i1, i2, 9, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 9, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 9, q) = 0d0
+                                momrhs(1, i1, i2, 9, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 9, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 9, q) = 0._wp
 
-                                momrhs(1, i1, i2, 10, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 10, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 10, q) = i2
-                                momrhs(3, i1, i2, 10, q) = 0d0
+                                momrhs(3, i1, i2, 10, q) = 0._wp
 
-                                momrhs(1, i1, i2, 11, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 11, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 11, q) = 0d0
+                                momrhs(1, i1, i2, 11, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 11, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 11, q) = 0._wp
 
-                                momrhs(1, i1, i2, 12, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 12, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 12, q) = 0d0
+                                momrhs(1, i1, i2, 12, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 12, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 12, q) = 0._wp
 
-                                momrhs(1, i1, i2, 13, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 13, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 13, q) = 0d0
+                                momrhs(1, i1, i2, 13, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 13, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 13, q) = 0._wp
 
-                                momrhs(1, i1, i2, 14, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 14, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 14, q) = i2
-                                momrhs(3, i1, i2, 14, q) = 0d0
+                                momrhs(3, i1, i2, 14, q) = 0._wp
 
-                                momrhs(1, i1, i2, 15, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 15, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 15, q) = 0d0
+                                momrhs(1, i1, i2, 15, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 15, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 15, q) = 0._wp
 
-                                momrhs(1, i1, i2, 16, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 16, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 16, q) = i2
-                                momrhs(3, i1, i2, 16, q) = 0d0
+                                momrhs(3, i1, i2, 16, q) = 0._wp
 
-                                momrhs(1, i1, i2, 17, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 17, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 17, q) = 0d0
+                                momrhs(1, i1, i2, 17, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 17, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 17, q) = 0._wp
 
-                                momrhs(1, i1, i2, 18, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 18, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 18, q) = 0d0
+                                momrhs(1, i1, i2, 18, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 18, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 18, q) = 0._wp
 
-                                momrhs(1, i1, i2, 19, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 19, q) = 2d0 + i2
-                                momrhs(3, i1, i2, 19, q) = 0d0
+                                momrhs(1, i1, i2, 19, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 19, q) = 2._wp + i2
+                                momrhs(3, i1, i2, 19, q) = 0._wp
 
-                                momrhs(1, i1, i2, 20, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 20, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 20, q) = 0d0
+                                momrhs(1, i1, i2, 20, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 20, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 20, q) = 0._wp
 
-                                momrhs(1, i1, i2, 21, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 21, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 21, q) = i2
-                                momrhs(3, i1, i2, 21, q) = 0d0
+                                momrhs(3, i1, i2, 21, q) = 0._wp
 
-                                momrhs(1, i1, i2, 22, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 22, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 22, q) = 0d0
+                                momrhs(1, i1, i2, 22, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 22, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 22, q) = 0._wp
 
-                                momrhs(1, i1, i2, 23, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 23, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 23, q) = i2
-                                momrhs(3, i1, i2, 23, q) = 0d0
+                                momrhs(3, i1, i2, 23, q) = 0._wp
 
-                                momrhs(1, i1, i2, 24, q) = -3d0 + i1
+                                momrhs(1, i1, i2, 24, q) = -3._wp + i1
                                 momrhs(2, i1, i2, 24, q) = i2
-                                momrhs(3, i1, i2, 24, q) = 0d0
+                                momrhs(3, i1, i2, 24, q) = 0._wp
 
-                                momrhs(1, i1, i2, 25, q) = -3d0 + i1
-                                momrhs(2, i1, i2, 25, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 25, q) = 0d0
+                                momrhs(1, i1, i2, 25, q) = -3._wp + i1
+                                momrhs(2, i1, i2, 25, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 25, q) = 0._wp
 
-                                momrhs(1, i1, i2, 26, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 26, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 26, q) = i2
-                                momrhs(3, i1, i2, 26, q) = 0d0
+                                momrhs(3, i1, i2, 26, q) = 0._wp
 
-                                momrhs(1, i1, i2, 27, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 27, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 27, q) = 0d0
+                                momrhs(1, i1, i2, 27, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 27, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 27, q) = 0._wp
 
-                                momrhs(1, i1, i2, 28, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 28, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 28, q) = i2
-                                momrhs(3, i1, i2, 28, q) = 0d0
+                                momrhs(3, i1, i2, 28, q) = 0._wp
 
-                                momrhs(1, i1, i2, 29, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 29, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 29, q) = i2
-                                momrhs(3, i1, i2, 29, q) = 0d0
+                                momrhs(3, i1, i2, 29, q) = 0._wp
 
-                                momrhs(1, i1, i2, 30, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 30, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 30, q) = 0d0
+                                momrhs(1, i1, i2, 30, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 30, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 30, q) = 0._wp
 
-                                momrhs(1, i1, i2, 31, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 31, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 31, q) = i2
-                                momrhs(3, i1, i2, 31, q) = 0d0
+                                momrhs(3, i1, i2, 31, q) = 0._wp
 
-                                momrhs(1, i1, i2, 32, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 32, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 32, q) = i2
-                                momrhs(3, i1, i2, 32, q) = 0d0
+                                momrhs(3, i1, i2, 32, q) = 0._wp
                             end if
                         end if
                     end do; end do
@@ -250,145 +250,145 @@ contains
                 do i1 = 0, 2; do i2 = 0, 2
                         if ((i1 + i2) <= 2) then
                             if (bubble_model == 3) then
-                                momrhs(1, i1, i2, 1, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 1, q) = -1.d0 + i2
-                                momrhs(3, i1, i2, 1, q) = 0d0
+                                momrhs(1, i1, i2, 1, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 1, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 1, q) = 0._wp
 
-                                momrhs(1, i1, i2, 2, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 2, q) = 1.d0 + i2
-                                momrhs(3, i1, i2, 2, q) = 0d0
+                                momrhs(1, i1, i2, 2, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 2, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 2, q) = 0._wp
 
-                                momrhs(1, i1, i2, 3, q) = -1.d0 + i1 - 3.d0*gam
-                                momrhs(2, i1, i2, 3, q) = -1.d0 + i2
-                                momrhs(3, i1, i2, 3, q) = 3.d0*gam
+                                momrhs(1, i1, i2, 3, q) = -1._wp + i1 - 3._wp*gam
+                                momrhs(2, i1, i2, 3, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 3, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 4, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 4, q) = 1.d0 + i2
-                                momrhs(3, i1, i2, 4, q) = 0d0
+                                momrhs(1, i1, i2, 4, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 4, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 4, q) = 0._wp
 
                                 if (.not. f_is_default(Re_inv)) then
                                     ! add viscosity
-                                    momrhs(1, i1, i2, 5, q) = -2.d0 + i1
+                                    momrhs(1, i1, i2, 5, q) = -2._wp + i1
                                     momrhs(2, i1, i2, 5, q) = i2
-                                    momrhs(3, i1, i2, 5, q) = 0d0
+                                    momrhs(3, i1, i2, 5, q) = 0._wp
                                 end if
 
                                 if (.not. f_is_default(Web)) then
                                     ! add surface tension
-                                    momrhs(1, i1, i2, 6, q) = -2.d0 + i1
-                                    momrhs(2, i1, i2, 6, q) = -1.d0 + i2
-                                    momrhs(3, i1, i2, 6, q) = 0d0
+                                    momrhs(1, i1, i2, 6, q) = -2._wp + i1
+                                    momrhs(2, i1, i2, 6, q) = -1._wp + i2
+                                    momrhs(3, i1, i2, 6, q) = 0._wp
                                 end if
 
-                                momrhs(1, i1, i2, 7, q) = -1.d0 + i1
-                                momrhs(2, i1, i2, 7, q) = -1.d0 + i2
-                                momrhs(3, i1, i2, 7, q) = 0d0
+                                momrhs(1, i1, i2, 7, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 7, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 7, q) = 0._wp
 
                             else if (bubble_model == 2) then
                                 ! KM with approximation of 1/(1-V/C) = 1+V/C
-                                momrhs(1, i1, i2, 1, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 1, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 1, q) = 0d0
+                                momrhs(1, i1, i2, 1, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 1, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 1, q) = 0._wp
 
-                                momrhs(1, i1, i2, 2, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 2, q) = 2d0 + i2
-                                momrhs(3, i1, i2, 2, q) = 0d0
+                                momrhs(1, i1, i2, 2, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 2, q) = 2._wp + i2
+                                momrhs(3, i1, i2, 2, q) = 0._wp
 
-                                momrhs(1, i1, i2, 3, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 3, q) = 3d0 + i2
-                                momrhs(3, i1, i2, 3, q) = 0d0
+                                momrhs(1, i1, i2, 3, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 3, q) = 3._wp + i2
+                                momrhs(3, i1, i2, 3, q) = 0._wp
 
-                                momrhs(1, i1, i2, 4, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 4, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 4, q) = 0d0
+                                momrhs(1, i1, i2, 4, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 4, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 4, q) = 0._wp
 
-                                momrhs(1, i1, i2, 5, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 5, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 5, q) = i2
-                                momrhs(3, i1, i2, 5, q) = 0d0
+                                momrhs(3, i1, i2, 5, q) = 0._wp
 
-                                momrhs(1, i1, i2, 6, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 6, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 6, q) = 0d0
+                                momrhs(1, i1, i2, 6, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 6, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 6, q) = 0._wp
 
-                                momrhs(1, i1, i2, 7, q) = -1d0 + i1 - 3d0*gam
-                                momrhs(2, i1, i2, 7, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 7, q) = 3d0*gam
+                                momrhs(1, i1, i2, 7, q) = -1._wp + i1 - 3._wp*gam
+                                momrhs(2, i1, i2, 7, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 7, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 8, q) = -1d0 + i1 - 3d0*gam
+                                momrhs(1, i1, i2, 8, q) = -1._wp + i1 - 3._wp*gam
                                 momrhs(2, i1, i2, 8, q) = i2
-                                momrhs(3, i1, i2, 8, q) = 3d0*gam
+                                momrhs(3, i1, i2, 8, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 9, q) = -1d0 + i1 - 3d0*gam
-                                momrhs(2, i1, i2, 9, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 9, q) = 3d0*gam
+                                momrhs(1, i1, i2, 9, q) = -1._wp + i1 - 3._wp*gam
+                                momrhs(2, i1, i2, 9, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 9, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 10, q) = -1d0 + i1 - 3d0*gam
+                                momrhs(1, i1, i2, 10, q) = -1._wp + i1 - 3._wp*gam
                                 momrhs(2, i1, i2, 10, q) = i2
-                                momrhs(3, i1, i2, 10, q) = 3d0*gam
+                                momrhs(3, i1, i2, 10, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 11, q) = -1d0 + i1 - 3d0*gam
-                                momrhs(2, i1, i2, 11, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 11, q) = 3d0*gam
+                                momrhs(1, i1, i2, 11, q) = -1._wp + i1 - 3._wp*gam
+                                momrhs(2, i1, i2, 11, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 11, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 12, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 12, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 12, q) = 0d0
+                                momrhs(1, i1, i2, 12, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 12, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 12, q) = 0._wp
 
-                                momrhs(1, i1, i2, 13, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 13, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 13, q) = 0d0
+                                momrhs(1, i1, i2, 13, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 13, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 13, q) = 0._wp
 
-                                momrhs(1, i1, i2, 14, q) = -1d0 + i1
+                                momrhs(1, i1, i2, 14, q) = -1._wp + i1
                                 momrhs(2, i1, i2, 14, q) = i2
-                                momrhs(3, i1, i2, 14, q) = 0d0
+                                momrhs(3, i1, i2, 14, q) = 0._wp
 
-                                momrhs(1, i1, i2, 15, q) = -1d0 + i1
-                                momrhs(2, i1, i2, 15, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 15, q) = 0d0
+                                momrhs(1, i1, i2, 15, q) = -1._wp + i1
+                                momrhs(2, i1, i2, 15, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 15, q) = 0._wp
 
-                                momrhs(1, i1, i2, 16, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 16, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 16, q) = i2
-                                momrhs(3, i1, i2, 16, q) = 0d0
+                                momrhs(3, i1, i2, 16, q) = 0._wp
 
-                                momrhs(1, i1, i2, 17, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 17, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 17, q) = 0d0
+                                momrhs(1, i1, i2, 17, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 17, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 17, q) = 0._wp
 
-                                momrhs(1, i1, i2, 18, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 18, q) = 1d0 + i2
-                                momrhs(3, i1, i2, 18, q) = 0d0
+                                momrhs(1, i1, i2, 18, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 18, q) = 1._wp + i2
+                                momrhs(3, i1, i2, 18, q) = 0._wp
 
-                                momrhs(1, i1, i2, 19, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 19, q) = 2d0 + i2
-                                momrhs(3, i1, i2, 19, q) = 0d0
+                                momrhs(1, i1, i2, 19, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 19, q) = 2._wp + i2
+                                momrhs(3, i1, i2, 19, q) = 0._wp
 
-                                momrhs(1, i1, i2, 20, q) = -2d0 + i1
-                                momrhs(2, i1, i2, 20, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 20, q) = 0d0
+                                momrhs(1, i1, i2, 20, q) = -2._wp + i1
+                                momrhs(2, i1, i2, 20, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 20, q) = 0._wp
 
-                                momrhs(1, i1, i2, 21, q) = -2d0 + i1
+                                momrhs(1, i1, i2, 21, q) = -2._wp + i1
                                 momrhs(2, i1, i2, 21, q) = i2
-                                momrhs(3, i1, i2, 21, q) = 0d0
+                                momrhs(3, i1, i2, 21, q) = 0._wp
 
-                                momrhs(1, i1, i2, 22, q) = -2d0 + i1 - 3d0*gam
-                                momrhs(2, i1, i2, 22, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 22, q) = 3d0*gam
+                                momrhs(1, i1, i2, 22, q) = -2._wp + i1 - 3._wp*gam
+                                momrhs(2, i1, i2, 22, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 22, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 23, q) = -2d0 + i1 - 3d0*gam
+                                momrhs(1, i1, i2, 23, q) = -2._wp + i1 - 3._wp*gam
                                 momrhs(2, i1, i2, 23, q) = i2
-                                momrhs(3, i1, i2, 23, q) = 3d0*gam
+                                momrhs(3, i1, i2, 23, q) = 3._wp*gam
 
-                                momrhs(1, i1, i2, 24, q) = -3d0 + i1
+                                momrhs(1, i1, i2, 24, q) = -3._wp + i1
                                 momrhs(2, i1, i2, 24, q) = i2
-                                momrhs(3, i1, i2, 24, q) = 0d0
+                                momrhs(3, i1, i2, 24, q) = 0._wp
 
-                                momrhs(1, i1, i2, 25, q) = -3d0 + i1
-                                momrhs(2, i1, i2, 25, q) = -1d0 + i2
-                                momrhs(3, i1, i2, 25, q) = 0d0
+                                momrhs(1, i1, i2, 25, q) = -3._wp + i1
+                                momrhs(2, i1, i2, 25, q) = -1._wp + i2
+                                momrhs(3, i1, i2, 25, q) = 0._wp
 
-                                momrhs(1, i1, i2, 26, q) = -2d0 + i1 - 3d0*gam
+                                momrhs(1, i1, i2, 26, q) = -2._wp + i1 - 3._wp*gam
                                 momrhs(2, i1, i2, 26, q) = i2
-                                momrhs(3, i1, i2, 26, q) = 3d0*gam
+                                momrhs(3, i1, i2, 26, q) = 3._wp*gam
 
                             end if
                         end if
@@ -421,12 +421,12 @@ contains
         type(scalar_field), dimension(sys_size), intent(in) :: q_cons_vf, q_prim_vf
         type(scalar_field), dimension(sys_size), intent(inout) :: rhs_vf
         type(scalar_field), dimension(sys_size), intent(in) :: flux_n_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, rhs_pb
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: mv, rhs_mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, rhs_pb
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: mv, rhs_mv
 
         integer :: i, j, k, l, q
 
-        real(kind(0d0)) :: nb_q, nb_dot, R, R2, nR, nR2, nR_dot, nR2_dot, var, AX
+        real(wp) :: nb_q, nb_dot, R, R2, nR, nR2, nR_dot, nR2_dot, var, AX
 
         if (idir == 1) then
 
@@ -445,36 +445,36 @@ contains
                                     R = q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                     R2 = q_prim_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                    if (R2 - R**2d0 > 0d0) then
-                                        var = R2 - R**2d0
+                                    if (R2 - R**2._wp > 0._wp) then
+                                        var = R2 - R**2._wp
                                     else
                                         var = verysmall
                                     end if
 
                                     if (q <= 2) then
-                                        AX = R - dsqrt(var)
+                                        AX = R - sqrt(var)
                                     else
-                                        AX = R + dsqrt(var)
+                                        AX = R + sqrt(var)
                                     end if
 
                                     nb_dot = flux_n_vf(bubxb + (i - 1)*nmom)%sf(j - 1, k, l) - flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k, l)
                                     nR_dot = flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j - 1, k, l) - flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                     nR2_dot = flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j - 1, k, l) - flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                    rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dx(j)*AX*nb_q**2)* &
+                                    rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dx(j)*AX*nb_q**2)* &
                                                             (nR_dot*nb_q - nR*nb_dot)*(pb(j, k, l, q, i))
 
                                     if (q <= 2) then
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dx(j)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dx(j)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                 (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dx(j)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dx(j)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
 
                                     else
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dx(j)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dx(j)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                 (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dx(j)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dx(j)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
                                     end if
 
                                 end do
@@ -529,36 +529,36 @@ contains
                                     R = q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                     R2 = q_prim_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                    if (R2 - R**2d0 > 0d0) then
-                                        var = R2 - R**2d0
+                                    if (R2 - R**2._wp > 0._wp) then
+                                        var = R2 - R**2._wp
                                     else
                                         var = verysmall
                                     end if
 
                                     if (q <= 2) then
-                                        AX = R - dsqrt(var)
+                                        AX = R - sqrt(var)
                                     else
-                                        AX = R + dsqrt(var)
+                                        AX = R + sqrt(var)
                                     end if
 
                                     nb_dot = flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k - 1, l) - flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k, l)
                                     nR_dot = flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k - 1, l) - flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                     nR2_dot = flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k - 1, l) - flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                    rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dy(k)*AX*nb_q**2)* &
+                                    rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dy(k)*AX*nb_q**2)* &
                                                             (nR_dot*nb_q - nR*nb_dot)*(pb(j, k, l, q, i))
 
                                     if (q <= 2) then
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dy(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dy(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                 (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dy(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dy(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
 
                                     else
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dy(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dy(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                 (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dy(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dy(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
                                     end if
 
                                 end do
@@ -586,36 +586,36 @@ contains
                                         R = q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                         R2 = q_prim_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                        if (R2 - R**2d0 > 0d0) then
-                                            var = R2 - R**2d0
+                                        if (R2 - R**2._wp > 0._wp) then
+                                            var = R2 - R**2._wp
                                         else
                                             var = verysmall
                                         end if
 
                                         if (q <= 2) then
-                                            AX = R - dsqrt(var)
+                                            AX = R - sqrt(var)
                                         else
-                                            AX = R + dsqrt(var)
+                                            AX = R + sqrt(var)
                                         end if
 
                                         nb_dot = q_prim_vf(contxe + idir)%sf(j, k, l)*(flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k, l - 1) - flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k, l))
                                         nR_dot = q_prim_vf(contxe + idir)%sf(j, k, l)*(flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l - 1) - flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l))
                                         nR2_dot = q_prim_vf(contxe + idir)%sf(j, k, l)*(flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l - 1) - flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l))
 
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dz(l)*y_cc(k)*AX*nb_q**2)* &
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dz(l)*y_cc(k)*AX*nb_q**2)* &
                                                                 (nR_dot*nb_q - nR*nb_dot)*(pb(j, k, l, q, i))
 
                                         if (q <= 2) then
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dz(l)*y_cc(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dz(l)*y_cc(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                     (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dz(l)*y_cc(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                    (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dz(l)*y_cc(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                    (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
 
                                         else
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dz(l)*y_cc(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dz(l)*y_cc(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                     (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dz(l)*y_cc(k)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                    (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dz(l)*y_cc(k)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                    (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
                                         end if
                                     end do
                                 end do
@@ -637,36 +637,36 @@ contains
                                         R = q_prim_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                         R2 = q_prim_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                        if (R2 - R**2d0 > 0d0) then
-                                            var = R2 - R**2d0
+                                        if (R2 - R**2._wp > 0._wp) then
+                                            var = R2 - R**2._wp
                                         else
                                             var = verysmall
                                         end if
 
                                         if (q <= 2) then
-                                            AX = R - dsqrt(var)
+                                            AX = R - sqrt(var)
                                         else
-                                            AX = R + dsqrt(var)
+                                            AX = R + sqrt(var)
                                         end if
 
                                         nb_dot = flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k, l - 1) - flux_n_vf(bubxb + (i - 1)*nmom)%sf(j, k, l)
                                         nR_dot = flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l - 1) - flux_n_vf(bubxb + 1 + (i - 1)*nmom)%sf(j, k, l)
                                         nR2_dot = flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l - 1) - flux_n_vf(bubxb + 3 + (i - 1)*nmom)%sf(j, k, l)
 
-                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dz(l)*AX*nb_q**2)* &
+                                        rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dz(l)*AX*nb_q**2)* &
                                                                 (nR_dot*nb_q - nR*nb_dot)*(pb(j, k, l, q, i))
 
                                         if (q <= 2) then
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dz(l)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dz(l)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                     (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3d0*gam/(dz(l)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                    (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) + 3._wp*gam/(dz(l)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                    (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
 
                                         else
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dz(l)*AX*nb_q**2*dsqrt(var)*2d0)* &
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dz(l)*AX*nb_q**2*sqrt(var)*2._wp)* &
                                                                     (nR2_dot*nb_q - nR2*nb_dot)*(pb(j, k, l, q, i))
-                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3d0*gam/(dz(l)*AX*nb_q**2*dsqrt(var)*2d0)* &
-                                                                    (-2d0*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
+                                            rhs_pb(j, k, l, q, i) = rhs_pb(j, k, l, q, i) - 3._wp*gam/(dz(l)*AX*nb_q**2*sqrt(var)*2._wp)* &
+                                                                    (-2._wp*(nR/nb_q)*(nR_dot*nb_q - nR*nb_dot))*(pb(j, k, l, q, i))
                                         end if
 
                                     end do
@@ -689,65 +689,65 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0.d0)), intent(in) :: pres, rho, c
-        real(kind(0.d0)), dimension(nterms, 0:2, 0:2), intent(out) :: coeffs
+        real(wp), intent(in) :: pres, rho, c
+        real(wp), dimension(nterms, 0:2, 0:2), intent(out) :: coeffs
 
         integer :: i1, i2
 
-        coeffs = 0d0
+        coeffs = 0._wp
 
         do i2 = 0, 2; do i1 = 0, 2
                 if ((i1 + i2) <= 2) then
                     if (bubble_model == 3) then
                         ! RPE
-                        coeffs(1, i1, i2) = -1d0*i2*pres/rho
-                        coeffs(2, i1, i2) = -3d0*i2/2d0
+                        coeffs(1, i1, i2) = -1._wp*i2*pres/rho
+                        coeffs(2, i1, i2) = -3._wp*i2/2._wp
                         coeffs(3, i1, i2) = i2/rho
                         coeffs(4, i1, i2) = i1
-                        if (.not. f_is_default(Re_inv)) coeffs(5, i1, i2) = -4d0*i2*Re_inv/rho
-                        if (.not. f_is_default(Web)) coeffs(6, i1, i2) = -2d0*i2/Web/rho
-                        coeffs(7, i1, i2) = 0d0
+                        if (.not. f_is_default(Re_inv)) coeffs(5, i1, i2) = -4._wp*i2*Re_inv/rho
+                        if (.not. f_is_default(Web)) coeffs(6, i1, i2) = -2._wp*i2/Web/rho
+                        coeffs(7, i1, i2) = 0._wp
                     else if (bubble_model == 2) then
                         ! KM with approximation of 1/(1-V/C) = 1+V/C
-                        coeffs(1, i1, i2) = -3d0*i2/2d0
+                        coeffs(1, i1, i2) = -3._wp*i2/2._wp
                         coeffs(2, i1, i2) = -i2/c
-                        coeffs(3, i1, i2) = i2/(2d0*c*c)
+                        coeffs(3, i1, i2) = i2/(2._wp*c*c)
                         coeffs(4, i1, i2) = -i2*pres/rho
-                        coeffs(5, i1, i2) = -2d0*i2*pres/(c*rho)
+                        coeffs(5, i1, i2) = -2._wp*i2*pres/(c*rho)
                         coeffs(6, i1, i2) = -i2*pres/(c*c*rho)
                         coeffs(7, i1, i2) = i2/rho
-                        coeffs(8, i1, i2) = 2d0*i2/(c*rho)
+                        coeffs(8, i1, i2) = 2._wp*i2/(c*rho)
                         coeffs(9, i1, i2) = i2/(c*c*rho)
-                        coeffs(10, i1, i2) = -3d0*i2*gam/(c*rho)
-                        coeffs(11, i1, i2) = -3d0*i2*gam/(c*c*rho)
+                        coeffs(10, i1, i2) = -3._wp*i2*gam/(c*rho)
+                        coeffs(11, i1, i2) = -3._wp*i2*gam/(c*c*rho)
                         coeffs(12, i1, i2) = i1
-                        coeffs(13, i1, i2) = 0d0
-                        coeffs(14, i1, i2) = 0d0
-                        coeffs(15, i1, i2) = 0d0
-                        if (.not. f_is_default(Re_inv)) coeffs(16, i1, i2) = -i2*4d0*Re_inv/rho
-                        if (.not. f_is_default(Web)) coeffs(17, i1, i2) = -i2*2d0/Web/rho
+                        coeffs(13, i1, i2) = 0._wp
+                        coeffs(14, i1, i2) = 0._wp
+                        coeffs(15, i1, i2) = 0._wp
+                        if (.not. f_is_default(Re_inv)) coeffs(16, i1, i2) = -i2*4._wp*Re_inv/rho
+                        if (.not. f_is_default(Web)) coeffs(17, i1, i2) = -i2*2._wp/Web/rho
                         if (.not. f_is_default(Re_inv)) then
-                            coeffs(18, i1, i2) = i2*6d0*Re_inv/(rho*c)
-                            coeffs(19, i1, i2) = -i2*2d0*Re_inv/(rho*c*c)
-                            coeffs(20, i1, i2) = i2*4d0*pres*Re_inv/(rho*rho*c)
-                            coeffs(21, i1, i2) = i2*4d0*pres*Re_inv/(rho*rho*c*c)
-                            coeffs(22, i1, i2) = -i2*4d0/(rho*rho*c)
-                            coeffs(23, i1, i2) = -i2*4d0/(rho*rho*c*c)
-                            coeffs(24, i1, i2) = i2*16d0*Re_inv*Re_inv/(rho*rho*c)
+                            coeffs(18, i1, i2) = i2*6._wp*Re_inv/(rho*c)
+                            coeffs(19, i1, i2) = -i2*2._wp*Re_inv/(rho*c*c)
+                            coeffs(20, i1, i2) = i2*4._wp*pres*Re_inv/(rho*rho*c)
+                            coeffs(21, i1, i2) = i2*4._wp*pres*Re_inv/(rho*rho*c*c)
+                            coeffs(22, i1, i2) = -i2*4._wp/(rho*rho*c)
+                            coeffs(23, i1, i2) = -i2*4._wp/(rho*rho*c*c)
+                            coeffs(24, i1, i2) = i2*16._wp*Re_inv*Re_inv/(rho*rho*c)
                             if (.not. f_is_default(Web)) then
-                                coeffs(25, i1, i2) = i2*8d0*Re_inv/Web/(rho*rho*c)
+                                coeffs(25, i1, i2) = i2*8._wp*Re_inv/Web/(rho*rho*c)
                             end if
-                            coeffs(26, i1, i2) = -12d0*i2*gam*Re_inv/(rho*rho*c*c)
+                            coeffs(26, i1, i2) = -12._wp*i2*gam*Re_inv/(rho*rho*c*c)
                         end if
-                        coeffs(27, i1, i2) = 3d0*i2*gam*R_v*Tw/(c*rho)
-                        coeffs(28, i1, i2) = 3d0*i2*gam*R_v*Tw/(c*c*rho)
+                        coeffs(27, i1, i2) = 3._wp*i2*gam*R_v*Tw/(c*rho)
+                        coeffs(28, i1, i2) = 3._wp*i2*gam*R_v*Tw/(c*c*rho)
                         if (.not. f_is_default(Re_inv)) then
-                            coeffs(29, i1, i2) = 12d0*i2*gam*R_v*Tw*Re_inv/(rho*rho*c*c)
+                            coeffs(29, i1, i2) = 12._wp*i2*gam*R_v*Tw*Re_inv/(rho*rho*c*c)
                         end if
-                        coeffs(30, i1, i2) = 3d0*i2*gam/(c*rho)
-                        coeffs(31, i1, i2) = 3d0*i2*gam/(c*c*rho)
+                        coeffs(30, i1, i2) = 3._wp*i2*gam/(c*rho)
+                        coeffs(31, i1, i2) = 3._wp*i2*gam/(c*c*rho)
                         if (.not. f_is_default(Re_inv)) then
-                            coeffs(32, i1, i2) = 12d0*i2*gam*Re_inv/(rho*rho*c*c)
+                            coeffs(32, i1, i2) = 12._wp*i2*gam*Re_inv/(rho*rho*c*c)
                         end if
                     end if
                 end if
@@ -763,55 +763,55 @@ contains
         !$acc routine seq
 #endif
 
-        real(kind(0.d0)), intent(inout) :: pres, rho, c
-        real(kind(0.d0)), dimension(nterms, 0:2, 0:2), intent(out) :: coeffs
+        real(wp), intent(inout) :: pres, rho, c
+        real(wp), dimension(nterms, 0:2, 0:2), intent(out) :: coeffs
 
         integer :: i1, i2
 
-        coeffs = 0d0
+        coeffs = 0._wp
 
         do i2 = 0, 2; do i1 = 0, 2
                 if ((i1 + i2) <= 2) then
                     if (bubble_model == 3) then
                         ! RPE
-                        coeffs(1, i1, i2) = -1d0*i2*pres/rho
-                        coeffs(2, i1, i2) = -3d0*i2/2d0
+                        coeffs(1, i1, i2) = -1._wp*i2*pres/rho
+                        coeffs(2, i1, i2) = -3._wp*i2/2._wp
                         coeffs(3, i1, i2) = i2/rho
                         coeffs(4, i1, i2) = i1
-                        if (.not. f_is_default(Re_inv)) coeffs(5, i1, i2) = -4d0*i2*Re_inv/rho
-                        if (.not. f_is_default(Web)) coeffs(6, i1, i2) = -2d0*i2/Web/rho
+                        if (.not. f_is_default(Re_inv)) coeffs(5, i1, i2) = -4._wp*i2*Re_inv/rho
+                        if (.not. f_is_default(Web)) coeffs(6, i1, i2) = -2._wp*i2/Web/rho
                         coeffs(7, i1, i2) = i2*pv/rho
                     else if (bubble_model == 2) then
                         ! KM with approximation of 1/(1-V/C) = 1+V/C
-                        coeffs(1, i1, i2) = -3d0*i2/2d0
+                        coeffs(1, i1, i2) = -3._wp*i2/2._wp
                         coeffs(2, i1, i2) = -i2/c
-                        coeffs(3, i1, i2) = i2/(2d0*c*c)
+                        coeffs(3, i1, i2) = i2/(2._wp*c*c)
                         coeffs(4, i1, i2) = -i2*pres/rho
-                        coeffs(5, i1, i2) = -2d0*i2*pres/(c*rho)
+                        coeffs(5, i1, i2) = -2._wp*i2*pres/(c*rho)
                         coeffs(6, i1, i2) = -i2*pres/(c*c*rho)
                         coeffs(7, i1, i2) = i2/rho
-                        coeffs(8, i1, i2) = 2d0*i2/(c*rho)
+                        coeffs(8, i1, i2) = 2._wp*i2/(c*rho)
                         coeffs(9, i1, i2) = i2/(c*c*rho)
-                        coeffs(10, i1, i2) = -3d0*i2*gam/(c*rho)
-                        coeffs(11, i1, i2) = -3d0*i2*gam/(c*c*rho)
+                        coeffs(10, i1, i2) = -3._wp*i2*gam/(c*rho)
+                        coeffs(11, i1, i2) = -3._wp*i2*gam/(c*c*rho)
                         coeffs(12, i1, i2) = i1
                         coeffs(13, i1, i2) = i2*(pv)/rho
-                        coeffs(14, i1, i2) = 2d0*i2*(pv)/(c*rho)
+                        coeffs(14, i1, i2) = 2._wp*i2*(pv)/(c*rho)
                         coeffs(15, i1, i2) = i2*(pv)/(c*c*rho)
-                        if (.not. f_is_default(Re_inv)) coeffs(16, i1, i2) = -i2*4d0*Re_inv/rho
-                        if (.not. f_is_default(Web)) coeffs(17, i1, i2) = -i2*2d0/Web/rho
+                        if (.not. f_is_default(Re_inv)) coeffs(16, i1, i2) = -i2*4._wp*Re_inv/rho
+                        if (.not. f_is_default(Web)) coeffs(17, i1, i2) = -i2*2._wp/Web/rho
                         if (.not. f_is_default(Re_inv)) then
-                            coeffs(18, i1, i2) = i2*6d0*Re_inv/(rho*c)
-                            coeffs(19, i1, i2) = -i2*2d0*Re_inv/(rho*c*c)
-                            coeffs(20, i1, i2) = i2*4d0*pres*Re_inv/(rho*rho*c)
-                            coeffs(21, i1, i2) = i2*4d0*pres*Re_inv/(rho*rho*c*c)
-                            coeffs(22, i1, i2) = -i2*4d0/(rho*rho*c)
-                            coeffs(23, i1, i2) = -i2*4d0/(rho*rho*c*c)
-                            coeffs(24, i1, i2) = i2*16d0*Re_inv*Re_inv/(rho*rho*c)
+                            coeffs(18, i1, i2) = i2*6._wp*Re_inv/(rho*c)
+                            coeffs(19, i1, i2) = -i2*2._wp*Re_inv/(rho*c*c)
+                            coeffs(20, i1, i2) = i2*4._wp*pres*Re_inv/(rho*rho*c)
+                            coeffs(21, i1, i2) = i2*4._wp*pres*Re_inv/(rho*rho*c*c)
+                            coeffs(22, i1, i2) = -i2*4._wp/(rho*rho*c)
+                            coeffs(23, i1, i2) = -i2*4._wp/(rho*rho*c*c)
+                            coeffs(24, i1, i2) = i2*16._wp*Re_inv*Re_inv/(rho*rho*c)
                             if (.not. f_is_default(Web)) then
-                                coeffs(25, i1, i2) = i2*8d0*Re_inv/Web/(rho*rho*c)
+                                coeffs(25, i1, i2) = i2*8._wp*Re_inv/Web/(rho*rho*c)
                             end if
-                            coeffs(26, i1, i2) = -12d0*i2*gam*Re_inv/(rho*rho*c*c)
+                            coeffs(26, i1, i2) = -12._wp*i2*gam*Re_inv/(rho*rho*c*c)
                         end if
                     end if
                 end if
@@ -824,16 +824,16 @@ contains
         type(scalar_field), dimension(:), intent(inout) :: q_cons_vf, q_prim_vf
         type(scalar_field), dimension(:), intent(inout) :: momsp
         type(scalar_field), dimension(0:, 0:, :), intent(inout) :: moms3d
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, rhs_pb
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: mv, rhs_mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, rhs_pb
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: mv, rhs_mv
         type(int_bounds_info), intent(in) :: ix, iy, iz
-        real(kind(0d0)), dimension(startx:, starty:, startz:) :: nbub_sc !> Unused Variable not sure what to put as intent
+        real(wp), dimension(startx:, starty:, startz:) :: nbub_sc !> Unused Variable not sure what to put as intent
 
-        real(kind(0d0)), dimension(nmom) :: moms, msum
-        real(kind(0d0)), dimension(nnode, nb) :: wght, abscX, abscY, wght_pb, wght_mv, wght_ht, ht
-        real(kind(0d0)), dimension(nterms, 0:2, 0:2) :: coeff
-        real(kind(0d0)) :: pres, rho, nbub, c, alf, momsum, drdt, drdt2, chi_vw, x_vw, rho_mw, k_mw, T_bar, grad_T
-        real(kind(0d0)) :: n_tait, B_tait
+        real(wp), dimension(nmom) :: moms, msum
+        real(wp), dimension(nnode, nb) :: wght, abscX, abscY, wght_pb, wght_mv, wght_ht, ht
+        real(wp), dimension(nterms, 0:2, 0:2) :: coeff
+        real(wp) :: pres, rho, nbub, c, alf, momsum, drdt, drdt2, chi_vw, x_vw, rho_mw, k_mw, T_bar, grad_T
+        real(wp) :: n_tait, B_tait
 
         integer :: id1, id2, id3
         integer :: i1, i2
@@ -853,12 +853,12 @@ contains
                     rho = q_prim_vf(contxb)%sf(id1, id2, id3)
                     if (bubble_model == 2) then
                         n_tait = gammas(1)
-                        n_tait = 1.d0/n_tait + 1.d0 !make this the usual little 'gamma'
+                        n_tait = 1._wp/n_tait + 1._wp !make this the usual little 'gamma'
                         B_tait = pi_infs(1)*(n_tait - 1)/n_tait
-                        c = n_tait*(pres + B_tait)*(1d0 - alf)/(rho)
+                        c = n_tait*(pres + B_tait)*(1._wp - alf)/(rho)
 
-                        if (c > 0.d0) then
-                            c = DSQRT(c)
+                        if (c > 0._wp) then
+                            c = sqrt(c)
                         else
                             c = sgm_eps
                         end if
@@ -871,7 +871,7 @@ contains
                     end if
 
                     ! SHB: Manually adjusted pressure here for no-coupling case
-                    ! pres = 1d0/0.3d0
+                    ! pres = 1._wp/0.3_wp
                     if (alf > small_alf) then
 
                         nbub = q_cons_vf(bubxb)%sf(id1, id2, id3)
@@ -884,7 +884,7 @@ contains
                                 moms(r) = q_prim_vf(bubmoms(q, r))%sf(id1, id2, id3)
                             end do
 
-                            moms(1) = 1d0
+                            moms(1) = 1._wp
 
                             call s_chyqmom(moms, wght(:, q), abscX(:, q), abscY(:, q))
 
@@ -898,13 +898,13 @@ contains
                                 !Account for bubble pressure, mass transfer rate and heat transfer rate in wght_pb, wght_mv and wght_ht using Preston model
                                 !$acc loop seq
                                 do j = 1, nnode
-                                    chi_vw = 1.d0/(1.d0 + R_v/R_n*(pb(id1, id2, id3, j, q)/pv - 1.d0))
+                                    chi_vw = 1._wp/(1._wp + R_v/R_n*(pb(id1, id2, id3, j, q)/pv - 1._wp))
                                     x_vw = M_n*chi_vw/(M_v + (M_n - M_v)*chi_vw)
-                                    k_mw = x_vw*k_v(q)/(x_vw + (1.d0 - x_vw)*phi_vn) &
-                                           + (1.d0 - x_vw)*k_n(q)/(x_vw*phi_nv + 1.d0 - x_vw)
+                                    k_mw = x_vw*k_v(q)/(x_vw + (1._wp - x_vw)*phi_vn) &
+                                           + (1._wp - x_vw)*k_n(q)/(x_vw*phi_nv + 1._wp - x_vw)
                                     rho_mw = pv/(chi_vw*R_v*Tw)
                                     rhs_mv(id1, id2, id3, j, q) = -Re_trans_c(q)*((mv(id1, id2, id3, j, q)/(mv(id1, id2, id3, j, q) + mass_n0(q))) - chi_vw)
-                                    rhs_mv(id1, id2, id3, j, q) = rho_mw*rhs_mv(id1, id2, id3, j, q)/Pe_c/(1.d0 - chi_vw)/abscX(j, q)
+                                    rhs_mv(id1, id2, id3, j, q) = rho_mw*rhs_mv(id1, id2, id3, j, q)/Pe_c/(1._wp - chi_vw)/abscX(j, q)
 
                                     T_bar = Tw*(pb(id1, id2, id3, j, q)/pb0(q))*(abscX(j, q)/R0(q))**3 &
                                             *(mass_n0(q) + mass_v0(q))/(mass_n0(q) + mv(id1, id2, id3, j, q))
@@ -924,7 +924,7 @@ contains
                                 !$acc loop seq
                                 do i1 = 0, 2
                                     if ((i1 + i2) <= 2) then
-                                        momsum = 0d0
+                                        momsum = 0._wp
                                         !$acc loop seq
                                         do j = 1, nterms
                                             ! Account for term with pb in Rayleigh Plesset equation
@@ -964,48 +964,48 @@ contains
                                 do j = 1, nnode
                                     ! Compute Rdot (drdt) at quadrature node in the ODE for pb (note this is not the same as bubble variable Rdot)
                                     drdt = msum(2)
-                                    if (moms(4) - moms(2)**2d0 > 0d0) then
+                                    if (moms(4) - moms(2)**2._wp > 0._wp) then
                                         if (j == 1 .or. j == 2) then
-                                            drdt2 = -1d0/(2d0*dsqrt(moms(4) - moms(2)**2d0))
+                                            drdt2 = -1._wp/(2._wp*sqrt(moms(4) - moms(2)**2._wp))
                                         else
-                                            drdt2 = 1d0/(2d0*dsqrt(moms(4) - moms(2)**2d0))
+                                            drdt2 = 1._wp/(2._wp*sqrt(moms(4) - moms(2)**2._wp))
                                         end if
                                     else
                                         ! Edge case where variance < 0
                                         if (j == 1 .or. j == 2) then
-                                            drdt2 = -1d0/(2d0*dsqrt(verysmall))
+                                            drdt2 = -1._wp/(2._wp*sqrt(verysmall))
                                         else
-                                            drdt2 = 1d0/(2d0*dsqrt(verysmall))
+                                            drdt2 = 1._wp/(2._wp*sqrt(verysmall))
                                         end if
                                     end if
 
-                                    drdt2 = drdt2*(msum(3) - 2d0*moms(2)*msum(2))
+                                    drdt2 = drdt2*(msum(3) - 2._wp*moms(2)*msum(2))
                                     drdt = drdt + drdt2
 
-                                    rhs_pb(id1, id2, id3, j, q) = (-3d0*gam*drdt/abscX(j, q))*(pb(id1, id2, id3, j, q))
-                                    rhs_pb(id1, id2, id3, j, q) = rhs_pb(id1, id2, id3, j, q) + (3d0*gam/abscX(j, q))*rhs_mv(id1, id2, id3, j, q)*R_v*Tw
-                                    rhs_pb(id1, id2, id3, j, q) = rhs_pb(id1, id2, id3, j, q) + (3d0*gam/abscX(j, q))*ht(j, q)
-                                    rhs_mv(id1, id2, id3, j, q) = rhs_mv(id1, id2, id3, j, q)*(4d0*pi*abscX(j, q)**2d0)
+                                    rhs_pb(id1, id2, id3, j, q) = (-3._wp*gam*drdt/abscX(j, q))*(pb(id1, id2, id3, j, q))
+                                    rhs_pb(id1, id2, id3, j, q) = rhs_pb(id1, id2, id3, j, q) + (3._wp*gam/abscX(j, q))*rhs_mv(id1, id2, id3, j, q)*R_v*Tw
+                                    rhs_pb(id1, id2, id3, j, q) = rhs_pb(id1, id2, id3, j, q) + (3._wp*gam/abscX(j, q))*ht(j, q)
+                                    rhs_mv(id1, id2, id3, j, q) = rhs_mv(id1, id2, id3, j, q)*(4._wp*pi*abscX(j, q)**2._wp)
                                 end do
 
                             end if
                         end do
 
                         ! Compute special high-order moments
-                        momsp(1)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght, 3d0, 0d0, 0d0)
-                        momsp(2)%sf(id1, id2, id3) = 4.d0*pi*nbub*f_quad(abscX, abscY, wght, 2d0, 1d0, 0d0)
-                        momsp(3)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght, 3d0, 2d0, 0d0)
-                        if (abs(gam - 1.d0) <= 1.d-4) then
+                        momsp(1)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght, 3._wp, 0._wp, 0._wp)
+                        momsp(2)%sf(id1, id2, id3) = 4._wp*pi*nbub*f_quad(abscX, abscY, wght, 2._wp, 1._wp, 0._wp)
+                        momsp(3)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght, 3._wp, 2._wp, 0._wp)
+                        if (abs(gam - 1._wp) <= 1.e-4_wp) then
                             ! Gam \approx 1, don't risk imaginary quadrature
-                            momsp(4)%sf(id1, id2, id3) = 1.d0
+                            momsp(4)%sf(id1, id2, id3) = 1._wp
                         else
                             !Special moment with bubble pressure pb
                             if (polytropic) then
-                                momsp(4)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght_pb, 3d0*(1d0 - gam), 0d0, 3d0*gam) + pv*f_quad(abscX, abscY, wght, 3d0, 0d0, 0d0) &
-                                                             - 4d0*Re_inv*f_quad(abscX, abscY, wght, 2d0, 1d0, 0d0) - (2d0/Web)*f_quad(abscX, abscY, wght, 2d0, 0d0, 0d0)
+                                momsp(4)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght_pb, 3._wp*(1._wp - gam), 0._wp, 3._wp*gam) + pv*f_quad(abscX, abscY, wght, 3._wp, 0._wp, 0._wp) &
+                                                             - 4._wp*Re_inv*f_quad(abscX, abscY, wght, 2._wp, 1._wp, 0._wp) - (2._wp/Web)*f_quad(abscX, abscY, wght, 2._wp, 0._wp, 0._wp)
                             else
-                                momsp(4)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght_pb, 3d0, 0d0, 0d0) &
-                                                             - 4d0*Re_inv*f_quad(abscX, abscY, wght, 2d0, 1d0, 0d0) - (2d0/Web)*f_quad(abscX, abscY, wght, 2d0, 0d0, 0d0)
+                                momsp(4)%sf(id1, id2, id3) = f_quad(abscX, abscY, wght_pb, 3._wp, 0._wp, 0._wp) &
+                                                             - 4._wp*Re_inv*f_quad(abscX, abscY, wght, 2._wp, 1._wp, 0._wp) - (2._wp/Web)*f_quad(abscX, abscY, wght, 2._wp, 0._wp, 0._wp)
                             end if
                         end if
 
@@ -1016,15 +1016,15 @@ contains
                             do i1 = 0, 2
                                 !$acc loop seq
                                 do i2 = 0, 2
-                                    moms3d(i1, i2, q)%sf(id1, id2, id3) = 0d0
+                                    moms3d(i1, i2, q)%sf(id1, id2, id3) = 0._wp
                                 end do
                             end do
                         end do
 
-                        momsp(1)%sf(id1, id2, id3) = 0d0
-                        momsp(2)%sf(id1, id2, id3) = 0d0
-                        momsp(3)%sf(id1, id2, id3) = 0d0
-                        momsp(4)%sf(id1, id2, id3) = 0d0
+                        momsp(1)%sf(id1, id2, id3) = 0._wp
+                        momsp(2)%sf(id1, id2, id3) = 0._wp
+                        momsp(3)%sf(id1, id2, id3) = 0._wp
+                        momsp(4)%sf(id1, id2, id3) = 0._wp
 
                     end if
 
@@ -1040,14 +1040,14 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(nmom), intent(in) :: momin
-        real(kind(0d0)), dimension(nnode), intent(inout) :: wght, abscX, abscY
+        real(wp), dimension(nmom), intent(in) :: momin
+        real(wp), dimension(nnode), intent(inout) :: wght, abscX, abscY
 
-        real(kind(0d0)), dimension(0:2, 0:2) :: moms
-        real(kind(0d0)), dimension(3) :: M1, M3
-        real(kind(0d0)), dimension(2) :: myrho, myrho3, up, up3, Vf
-        real(kind(0d0)) :: bu, bv, d20, d11, d02, c20, c11, c02
-        real(kind(0d0)) :: mu2avg, mu2, vp21, vp22, rho21, rho22
+        real(wp), dimension(0:2, 0:2) :: moms
+        real(wp), dimension(3) :: M1, M3
+        real(wp), dimension(2) :: myrho, myrho3, up, up3, Vf
+        real(wp) :: bu, bv, d20, d11, d02, c20, c11, c02
+        real(wp) :: mu2avg, mu2, vp21, vp22, rho21, rho22
 
         moms(0, 0) = momin(1)
         moms(1, 0) = momin(2)
@@ -1062,18 +1062,18 @@ contains
         d11 = moms(1, 1)/moms(0, 0)
         d02 = moms(0, 2)/moms(0, 0)
 
-        c20 = d20 - bu**2d0; 
+        c20 = d20 - bu**2._wp; 
         c11 = d11 - bu*bv; 
-        c02 = d02 - bv**2d0; 
-        M1 = (/1d0, 0d0, c20/)
+        c02 = d02 - bv**2._wp; 
+        M1 = (/1._wp, 0._wp, c20/)
         call s_hyqmom(myrho, up, M1)
         Vf = c11*up/c20
 
-        mu2avg = c02 - sum(myrho(:)*(Vf(:)**2d0))
+        mu2avg = c02 - sum(myrho(:)*(Vf(:)**2._wp))
 
-        mu2avg = maxval((/mu2avg, 0d0/))
+        mu2avg = maxval((/mu2avg, 0._wp/))
         mu2 = mu2avg
-        M3 = (/1d0, 0d0, mu2/)
+        M3 = (/1._wp, 0._wp, mu2/)
         call s_hyqmom(myrho3, up3, M3)
 
         vp21 = up3(1)
@@ -1107,31 +1107,31 @@ contains
 #else
         !$acc routine seq
 #endif
-        real(kind(0d0)), dimension(2), intent(inout) :: frho, fup
-        real(kind(0d0)), dimension(3), intent(in) :: fmom
+        real(wp), dimension(2), intent(inout) :: frho, fup
+        real(wp), dimension(3), intent(in) :: fmom
 
-        real(kind(0d0)) :: bu, d2, c2
+        real(wp) :: bu, d2, c2
 
         bu = fmom(2)/fmom(1)
         d2 = fmom(3)/fmom(1)
-        c2 = d2 - bu**2d0
-        frho(1) = fmom(1)/2d0; 
-        frho(2) = fmom(1)/2d0; 
+        c2 = d2 - bu**2._wp
+        frho(1) = fmom(1)/2._wp; 
+        frho(2) = fmom(1)/2._wp; 
         c2 = maxval((/c2, verysmall/))
-        fup(1) = bu - DSQRT(c2)
-        fup(2) = bu + DSQRT(c2)
+        fup(1) = bu - sqrt(c2)
+        fup(2) = bu + sqrt(c2)
 
     end subroutine s_hyqmom
 
     function f_quad(abscX, abscY, wght_in, q, r, s)
         !$acc routine seq
-        real(kind(0.d0)), dimension(nnode, nb), intent(in) :: abscX, abscY, wght_in
-        real(kind(0.d0)), intent(in) :: q, r, s
+        real(wp), dimension(nnode, nb), intent(in) :: abscX, abscY, wght_in
+        real(wp), intent(in) :: q, r, s
 
-        real(kind(0.d0)) :: f_quad_RV, f_quad
+        real(wp) :: f_quad_RV, f_quad
         integer :: i
 
-        f_quad = 0d0
+        f_quad = 0._wp
         do i = 1, nb
             f_quad_RV = sum(wght_in(:, i)*(abscX(:, i)**q)*(abscY(:, i)**r))
             f_quad = f_quad + weight(i)*(R0(i)**s)*f_quad_RV
@@ -1141,10 +1141,10 @@ contains
 
     function f_quad2D(abscX, abscY, wght_in, pow)
         !$acc routine seq
-        real(kind(0.d0)), dimension(nnode), intent(in) :: abscX, abscY, wght_in
-        real(kind(0.d0)), dimension(3), intent(in) :: pow
+        real(wp), dimension(nnode), intent(in) :: abscX, abscY, wght_in
+        real(wp), dimension(3), intent(in) :: pow
 
-        real(kind(0.d0)) :: f_quad2D
+        real(wp) :: f_quad2D
 
         f_quad2D = sum(wght_in(:)*(abscX(:)**pow(1))*(abscY(:)**pow(2)))
     end function f_quad2D
diff --git a/src/simulation/m_rhs.fpp b/src/simulation/m_rhs.fpp
index 0e5572b59..2f89dc3eb 100644
--- a/src/simulation/m_rhs.fpp
+++ b/src/simulation/m_rhs.fpp
@@ -6,7 +6,7 @@
 #:include 'macros.fpp'
 
 !> @brief The module contains the subroutines used to calculate the right-
-!!              hand-side (RHS) in the quasi-conservative, shock- and interface-
+!!              hane-side (RHS) in the quasi-conservative, shock- and interface-
 !!              capturing finite-volume framework for the multicomponent Navier-
 !!              Stokes equations supplemented by appropriate advection equations
 !!              used to capture the material interfaces. The system of equations
@@ -147,20 +147,20 @@ module m_rhs
     !> @}
     !$acc declare create(alf_sum)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: blkmod1, blkmod2, alpha1, alpha2, Kterm
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: qL_rsx_vf, qL_rsy_vf, qL_rsz_vf, qR_rsx_vf, qR_rsy_vf, qR_rsz_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: dqL_rsx_vf, dqL_rsy_vf, dqL_rsz_vf, dqR_rsx_vf, dqR_rsy_vf, dqR_rsz_vf
+    real(wp), allocatable, dimension(:, :, :) :: blkmod1, blkmod2, alpha1, alpha2, Kterm
+    real(wp), allocatable, dimension(:, :, :, :) :: qL_rsx_vf, qL_rsy_vf, qL_rsz_vf, qR_rsx_vf, qR_rsy_vf, qR_rsz_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: dqL_rsx_vf, dqL_rsy_vf, dqL_rsz_vf, dqR_rsx_vf, dqR_rsy_vf, dqR_rsz_vf
     !$acc declare create(blkmod1, blkmod2, alpha1, alpha2, Kterm)
     !$acc declare create(qL_rsx_vf, qL_rsy_vf, qL_rsz_vf, qR_rsx_vf, qR_rsy_vf, qR_rsz_vf)
     !$acc declare create(dqL_rsx_vf, dqL_rsy_vf, dqL_rsz_vf, dqR_rsx_vf, dqR_rsy_vf, dqR_rsz_vf)
 
-    real(kind(0d0)), allocatable, dimension(:) :: gamma_min, pres_inf
+    real(wp), allocatable, dimension(:) :: gamma_min, pres_inf
     !$acc declare create(gamma_min, pres_inf)
 
-    real(kind(0d0)), allocatable, dimension(:, :) :: Res
+    real(wp), allocatable, dimension(:, :) :: Res
     !$acc declare create(Res)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: nbub !< Bubble number density
+    real(wp), allocatable, dimension(:, :, :) :: nbub !< Bubble number density
     !$acc declare create(nbub)
 
 contains
@@ -571,8 +571,8 @@ contains
         @:ALLOCATE(gamma_min(1:num_fluids), pres_inf(1:num_fluids))
 
         do i = 1, num_fluids
-            gamma_min(i) = 1d0/fluid_pp(i)%gamma + 1d0
-            pres_inf(i) = fluid_pp(i)%pi_inf/(1d0 + fluid_pp(i)%gamma)
+            gamma_min(i) = 1._wp/fluid_pp(i)%gamma + 1._wp
+            pres_inf(i) = fluid_pp(i)%pi_inf/(1._wp + fluid_pp(i)%gamma)
         end do
         !$acc update device(gamma_min, pres_inf)
 
@@ -595,7 +595,7 @@ contains
                 do l = startz, p - startz
                     do k = starty, n - starty
                         do j = startx, m - startx
-                            flux_gsrc_n(id)%vf(i)%sf(j, k, l) = 0d0
+                            flux_gsrc_n(id)%vf(i)%sf(j, k, l) = 0._wp
                         end do
                     end do
                 end do
@@ -613,13 +613,13 @@ contains
         type(scalar_field), dimension(sys_size), intent(inout) :: q_cons_vf
         type(scalar_field), dimension(sys_size), intent(inout) :: q_prim_vf
         type(scalar_field), dimension(sys_size), intent(inout) :: rhs_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, rhs_pb
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: mv, rhs_mv
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: pb, rhs_pb
+        real(wp), dimension(startx:, starty:, startz:, 1:, 1:), intent(inout) :: mv, rhs_mv
         integer, intent(in) :: t_step
-        real(kind(0d0)), intent(inout) :: time_avg
+        real(wp), intent(inout) :: time_avg
 
-        real(kind(0d0)), dimension(0:m, 0:n, 0:p) :: nbub
-        real(kind(0d0)) :: t_start, t_finish
+        real(wp), dimension(0:m, 0:n, 0:p) :: nbub
+        real(wp) :: t_start, t_finish
         integer :: i, j, k, l, id !< Generic loop iterators
 
         call nvtxStartRange("COMPUTE-RHS")
@@ -646,14 +646,14 @@ contains
             do l = idwbuff(3)%beg, idwbuff(3)%end
                 do k = idwbuff(2)%beg, idwbuff(2)%end
                     do j = idwbuff(1)%beg, idwbuff(1)%end
-                        alf_sum%sf(j, k, l) = 0d0
+                        alf_sum%sf(j, k, l) = 0._wp
                         !$acc loop seq
                         do i = advxb, advxe - 1
                             alf_sum%sf(j, k, l) = alf_sum%sf(j, k, l) + q_cons_qp%vf(i)%sf(j, k, l)
                         end do
                         !$acc loop seq
                         do i = advxb, advxe - 1
-                            q_cons_qp%vf(i)%sf(j, k, l) = q_cons_qp%vf(i)%sf(j, k, l)*(1.d0 - q_cons_qp%vf(alf_idx)%sf(j, k, l)) &
+                            q_cons_qp%vf(i)%sf(j, k, l) = q_cons_qp%vf(i)%sf(j, k, l)*(1._wp - q_cons_qp%vf(alf_idx)%sf(j, k, l)) &
                                                           /alf_sum%sf(j, k, l)
                         end do
                     end do
@@ -867,7 +867,7 @@ contains
                     do j = 0, m
                         if (ib_markers%sf(j, k, l) /= 0) then
                             do i = 1, sys_size
-                                rhs_vf(i)%sf(j, k, l) = 0d0
+                                rhs_vf(i)%sf(j, k, l) = 0._wp
                             end do
                         end if
                     end do
@@ -899,7 +899,7 @@ contains
 
         if (chemistry) then
             !$acc kernels
-            rhs_vf(T_idx)%sf(:, :, :) = 0d0
+            rhs_vf(T_idx)%sf(:, :, :) = 0.0_wp
             !$acc end kernels
 
             if (chem_params%reactions) then
@@ -929,7 +929,7 @@ contains
         if (t_step >= 4) then
             time_avg = (abs(t_finish - t_start) + (t_step - 4)*time_avg)/(t_step - 3)
         else
-            time_avg = 0d0
+            time_avg = 0._wp
         end if
         ! ==================================================================
 
@@ -952,9 +952,9 @@ contains
             do l = 0, p
                 do k = 0, n
                     do j = 0, m
-                        blkmod1(j, k, l) = ((gammas(1) + 1d0)*q_prim_vf%vf(E_idx)%sf(j, k, l) + &
+                        blkmod1(j, k, l) = ((gammas(1) + 1._wp)*q_prim_vf%vf(E_idx)%sf(j, k, l) + &
                                             pi_infs(1))/gammas(1)
-                        blkmod2(j, k, l) = ((gammas(2) + 1d0)*q_prim_vf%vf(E_idx)%sf(j, k, l) + &
+                        blkmod2(j, k, l) = ((gammas(2) + 1._wp)*q_prim_vf%vf(E_idx)%sf(j, k, l) + &
                                             pi_infs(2))/gammas(2)
                         alpha1(j, k, l) = q_cons_vf%vf(advxb)%sf(j, k, l)
 
@@ -988,7 +988,7 @@ contains
                 do q = 0, p
                     do l = 0, n
                         do k = 0, m
-                            rhs_vf(j)%sf(k, l, q) = 1d0/dx(k)* &
+                            rhs_vf(j)%sf(k, l, q) = 1._wp/dx(k)* &
                                                     (flux_n(1)%vf(j)%sf(k - 1, l, q) &
                                                      - flux_n(1)%vf(j)%sf(k, l, q))
                         end do
@@ -1003,7 +1003,7 @@ contains
                         do j = 0, m
                             do i = 1, num_fluids
                                 rhs_vf(i + intxb - 1)%sf(j, k, l) = &
-                                    rhs_vf(i + intxb - 1)%sf(j, k, l) - 1d0/dx(j)* &
+                                    rhs_vf(i + intxb - 1)%sf(j, k, l) - 1._wp/dx(j)* &
                                     q_cons_vf%vf(i + advxb - 1)%sf(j, k, l)* &
                                     q_prim_vf%vf(E_idx)%sf(j, k, l)* &
                                     (flux_src_n(1)%vf(advxb)%sf(j, k, l) - &
@@ -1021,7 +1021,7 @@ contains
                         do l = 0, n
                             do k = 0, m
                                 rhs_vf(j)%sf(k, l, q) = &
-                                    rhs_vf(j)%sf(k, l, q) + 1d0/dx(k)* &
+                                    rhs_vf(j)%sf(k, l, q) + 1._wp/dx(k)* &
                                     q_prim_vf%vf(contxe + idir)%sf(k, l, q)* &
                                     (flux_src_n(1)%vf(j)%sf(k - 1, l, q) &
                                      - flux_src_n(1)%vf(j)%sf(k, l, q))
@@ -1038,7 +1038,7 @@ contains
                                 do l = 0, n
                                     do k = 0, m
                                         rhs_vf(j)%sf(k, l, q) = &
-                                            rhs_vf(j)%sf(k, l, q) + 1d0/dx(k)* &
+                                            rhs_vf(j)%sf(k, l, q) + 1._wp/dx(k)* &
                                             (q_cons_vf%vf(j)%sf(k, l, q) - Kterm(k, l, q))* &
                                             (flux_src_n(1)%vf(j)%sf(k, l, q) &
                                              - flux_src_n(1)%vf(j)%sf(k - 1, l, q))
@@ -1051,7 +1051,7 @@ contains
                                 do l = 0, n
                                     do k = 0, m
                                         rhs_vf(j)%sf(k, l, q) = &
-                                            rhs_vf(j)%sf(k, l, q) + 1d0/dx(k)* &
+                                            rhs_vf(j)%sf(k, l, q) + 1._wp/dx(k)* &
                                             (q_cons_vf%vf(j)%sf(k, l, q) + Kterm(k, l, q))* &
                                             (flux_src_n(1)%vf(j)%sf(k, l, q) &
                                              - flux_src_n(1)%vf(j)%sf(k - 1, l, q))
@@ -1067,7 +1067,7 @@ contains
                             do l = 0, n
                                 do k = 0, m
                                     rhs_vf(j)%sf(k, l, q) = &
-                                        rhs_vf(j)%sf(k, l, q) + 1d0/dx(k)* &
+                                        rhs_vf(j)%sf(k, l, q) + 1._wp/dx(k)* &
                                         q_cons_vf%vf(j)%sf(k, l, q)* &
                                         (flux_src_n(1)%vf(j)%sf(k, l, q) &
                                          - flux_src_n(1)%vf(j)%sf(k - 1, l, q))
@@ -1098,7 +1098,7 @@ contains
                     do k = 0, n
                         do q = 0, m
                             rhs_vf(j)%sf(q, k, l) = &
-                                rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                 (flux_n(2)%vf(j)%sf(q, k - 1, l) &
                                  - flux_n(2)%vf(j)%sf(q, k, l))
                         end do
@@ -1113,7 +1113,7 @@ contains
                         do j = 0, m
                             do i = 1, num_fluids
                                 rhs_vf(i + intxb - 1)%sf(j, k, l) = &
-                                    rhs_vf(i + intxb - 1)%sf(j, k, l) - 1d0/dy(k)* &
+                                    rhs_vf(i + intxb - 1)%sf(j, k, l) - 1._wp/dy(k)* &
                                     q_cons_vf%vf(i + advxb - 1)%sf(j, k, l)* &
                                     q_prim_vf%vf(E_idx)%sf(j, k, l)* &
                                     (flux_src_n(2)%vf(advxb)%sf(j, k, l) - &
@@ -1130,7 +1130,7 @@ contains
                             do j = 0, m
                                 do i = 1, num_fluids
                                     rhs_vf(i + intxb - 1)%sf(j, k, l) = &
-                                        rhs_vf(i + intxb - 1)%sf(j, k, l) - 5d-1/y_cc(k)* &
+                                        rhs_vf(i + intxb - 1)%sf(j, k, l) - 5e-1_wp/y_cc(k)* &
                                         q_cons_vf%vf(i + advxb - 1)%sf(j, k, l)* &
                                         q_prim_vf%vf(E_idx)%sf(j, k, l)* &
                                         (flux_src_n(2)%vf(advxb)%sf(j, k, l) + &
@@ -1149,7 +1149,7 @@ contains
                         do k = 0, n
                             do q = 0, m
                                 rhs_vf(j)%sf(q, k, l) = &
-                                    rhs_vf(j)%sf(q, k, l) - 5d-1/y_cc(k)* &
+                                    rhs_vf(j)%sf(q, k, l) - 5e-1_wp/y_cc(k)* &
                                     (flux_gsrc_n(2)%vf(j)%sf(q, k - 1, l) &
                                      + flux_gsrc_n(2)%vf(j)%sf(q, k, l))
                             end do
@@ -1165,7 +1165,7 @@ contains
                         do k = 0, n
                             do q = 0, m
                                 rhs_vf(j)%sf(q, k, l) = &
-                                    rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                    rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                     q_prim_vf%vf(contxe + idir)%sf(q, k, l)* &
                                     (flux_src_n(2)%vf(j)%sf(q, k - 1, l) &
                                      - flux_src_n(2)%vf(j)%sf(q, k, l))
@@ -1183,7 +1183,7 @@ contains
                                 do k = 0, n
                                     do q = 0, m
                                         rhs_vf(j)%sf(q, k, l) = &
-                                            rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                            rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                             (q_cons_vf%vf(j)%sf(q, k, l) - Kterm(q, k, l))* &
                                             (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                              - flux_src_n(2)%vf(j)%sf(q, k - 1, l))
@@ -1197,7 +1197,7 @@ contains
                                         do q = 0, m
                                             rhs_vf(j)%sf(q, k, l) = &
                                                 rhs_vf(j)%sf(q, k, l) - &
-                                                (Kterm(q, k, l)/2d0/y_cc(k))* &
+                                                (Kterm(q, k, l)/2._wp/y_cc(k))* &
                                                 (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                                  + flux_src_n(2)%vf(j)%sf(q, k - 1, l))
                                         end do
@@ -1210,7 +1210,7 @@ contains
                                 do k = 0, n
                                     do q = 0, m
                                         rhs_vf(j)%sf(q, k, l) = &
-                                            rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                            rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                             (q_cons_vf%vf(j)%sf(q, k, l) + Kterm(q, k, l))* &
                                             (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                              - flux_src_n(2)%vf(j)%sf(q, k - 1, l))
@@ -1224,7 +1224,7 @@ contains
                                         do q = 0, m
                                             rhs_vf(j)%sf(q, k, l) = &
                                                 rhs_vf(j)%sf(q, k, l) + &
-                                                (Kterm(q, k, l)/2d0/y_cc(k))* &
+                                                (Kterm(q, k, l)/2._wp/y_cc(k))* &
                                                 (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                                  + flux_src_n(2)%vf(j)%sf(q, k - 1, l))
                                         end do
@@ -1240,7 +1240,7 @@ contains
                             do k = 0, n
                                 do q = 0, m
                                     rhs_vf(j)%sf(q, k, l) = &
-                                        rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                        rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                         q_cons_vf%vf(j)%sf(q, k, l)* &
                                         (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                          - flux_src_n(2)%vf(j)%sf(q, k - 1, l))
@@ -1273,7 +1273,7 @@ contains
                         do q = 0, n
                             do l = 0, m
                                 rhs_vf(j)%sf(l, q, k) = &
-                                    rhs_vf(j)%sf(l, q, k) + 1d0/dz(k)/y_cc(q)* &
+                                    rhs_vf(j)%sf(l, q, k) + 1._wp/dz(k)/y_cc(q)* &
                                     q_prim_vf%vf(contxe + idir)%sf(l, q, k)* &
                                     (flux_n(3)%vf(j)%sf(l, q, k - 1) &
                                      - flux_n(3)%vf(j)%sf(l, q, k))
@@ -1288,7 +1288,7 @@ contains
                         do q = 0, n
                             do l = 0, m
                                 rhs_vf(j)%sf(l, q, k) = &
-                                    rhs_vf(j)%sf(l, q, k) - 5d-1/y_cc(q)* &
+                                    rhs_vf(j)%sf(l, q, k) - 5e-1_wp/y_cc(q)* &
                                     (flux_gsrc_n(3)%vf(j)%sf(l, q, k - 1) &
                                      - flux_gsrc_n(3)%vf(j)%sf(l, q, k))
                             end do
@@ -1303,7 +1303,7 @@ contains
                         do q = 0, n
                             do l = 0, m
                                 rhs_vf(j)%sf(l, q, k) = &
-                                    rhs_vf(j)%sf(l, q, k) + 1d0/dz(k)* &
+                                    rhs_vf(j)%sf(l, q, k) + 1._wp/dz(k)* &
                                     (flux_n(3)%vf(j)%sf(l, q, k - 1) &
                                      - flux_n(3)%vf(j)%sf(l, q, k))
                             end do
@@ -1319,7 +1319,7 @@ contains
                         do j = 0, m
                             do i = 1, num_fluids
                                 rhs_vf(i + intxb - 1)%sf(j, k, l) = &
-                                    rhs_vf(i + intxb - 1)%sf(j, k, l) - 1d0/dz(l)* &
+                                    rhs_vf(i + intxb - 1)%sf(j, k, l) - 1._wp/dz(l)* &
                                     q_cons_vf%vf(i + advxb - 1)%sf(j, k, l)* &
                                     q_prim_vf%vf(E_idx)%sf(j, k, l)* &
                                     (flux_src_n(3)%vf(advxb)%sf(j, k, l) - &
@@ -1338,7 +1338,7 @@ contains
                             do k = 0, n
                                 do q = 0, m
                                     rhs_vf(j)%sf(q, k, l) = &
-                                        rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                        rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                         q_prim_vf%vf(contxe + idir)%sf(q, k, l)* &
                                         (flux_src_n(2)%vf(j)%sf(q, k - 1, l) &
                                          - flux_src_n(2)%vf(j)%sf(q, k, l))
@@ -1356,7 +1356,7 @@ contains
                                     do k = 0, n
                                         do q = 0, m
                                             rhs_vf(j)%sf(q, k, l) = &
-                                                rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                                rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                                 (q_cons_vf%vf(j)%sf(q, k, l) - Kterm(q, k, l))* &
                                                 (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                                  - flux_src_n(2)%vf(j)%sf(q, k - 1, l))
@@ -1370,7 +1370,7 @@ contains
                                             do q = 0, m
                                                 rhs_vf(j)%sf(q, k, l) = &
                                                     rhs_vf(j)%sf(q, k, l) - &
-                                                    (Kterm(q, k, l)/2d0/y_cc(k))* &
+                                                    (Kterm(q, k, l)/2._wp/y_cc(k))* &
                                                     (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                                      + flux_src_n(2)%vf(j)%sf(q, k - 1, l))
                                             end do
@@ -1383,7 +1383,7 @@ contains
                                     do k = 0, n
                                         do q = 0, m
                                             rhs_vf(j)%sf(q, k, l) = &
-                                                rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                                rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                                 (q_cons_vf%vf(j)%sf(q, k, l) + Kterm(q, k, l))* &
                                                 (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                                  - flux_src_n(2)%vf(j)%sf(q, k - 1, l))
@@ -1397,7 +1397,7 @@ contains
                                             do q = 0, m
                                                 rhs_vf(j)%sf(q, k, l) = &
                                                     rhs_vf(j)%sf(q, k, l) + &
-                                                    (Kterm(q, k, l)/2d0/y_cc(k))* &
+                                                    (Kterm(q, k, l)/2._wp/y_cc(k))* &
                                                     (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                                      + flux_src_n(2)%vf(j)%sf(q, k - 1, l))
                                             end do
@@ -1413,7 +1413,7 @@ contains
                                 do k = 0, n
                                     do q = 0, m
                                         rhs_vf(j)%sf(q, k, l) = &
-                                            rhs_vf(j)%sf(q, k, l) + 1d0/dy(k)* &
+                                            rhs_vf(j)%sf(q, k, l) + 1._wp/dy(k)* &
                                             q_cons_vf%vf(j)%sf(q, k, l)* &
                                             (flux_src_n(2)%vf(j)%sf(q, k, l) &
                                              - flux_src_n(2)%vf(j)%sf(q, k - 1, l))
@@ -1431,7 +1431,7 @@ contains
                             do q = 0, n
                                 do l = 0, m
                                     rhs_vf(j)%sf(l, q, k) = &
-                                        rhs_vf(j)%sf(l, q, k) + 1d0/dz(k)* &
+                                        rhs_vf(j)%sf(l, q, k) + 1._wp/dz(k)* &
                                         q_prim_vf%vf(contxe + idir)%sf(l, q, k)* &
                                         (flux_src_n(3)%vf(j)%sf(l, q, k - 1) &
                                          - flux_src_n(3)%vf(j)%sf(l, q, k))
@@ -1448,7 +1448,7 @@ contains
                                     do q = 0, n
                                         do l = 0, m
                                             rhs_vf(j)%sf(l, q, k) = &
-                                                rhs_vf(j)%sf(l, q, k) + 1d0/dz(k)* &
+                                                rhs_vf(j)%sf(l, q, k) + 1._wp/dz(k)* &
                                                 (q_cons_vf%vf(j)%sf(l, q, k) - Kterm(l, q, k))* &
                                                 (flux_src_n(3)%vf(j)%sf(l, q, k) &
                                                  - flux_src_n(3)%vf(j)%sf(l, q, k - 1))
@@ -1461,7 +1461,7 @@ contains
                                     do q = 0, n
                                         do l = 0, m
                                             rhs_vf(j)%sf(l, q, k) = &
-                                                rhs_vf(j)%sf(l, q, k) + 1d0/dz(k)* &
+                                                rhs_vf(j)%sf(l, q, k) + 1._wp/dz(k)* &
                                                 (q_cons_vf%vf(j)%sf(l, q, k) + Kterm(l, q, k))* &
                                                 (flux_src_n(3)%vf(j)%sf(l, q, k) &
                                                  - flux_src_n(3)%vf(j)%sf(l, q, k - 1))
@@ -1477,7 +1477,7 @@ contains
                                 do q = 0, n
                                     do l = 0, m
                                         rhs_vf(j)%sf(l, q, k) = &
-                                            rhs_vf(j)%sf(l, q, k) + 1d0/dz(k)* &
+                                            rhs_vf(j)%sf(l, q, k) + 1._wp/dz(k)* &
                                             q_cons_vf%vf(j)%sf(l, q, k)* &
                                             (flux_src_n(3)%vf(j)%sf(l, q, k) &
                                              - flux_src_n(3)%vf(j)%sf(l, q, k - 1))
@@ -1511,7 +1511,7 @@ contains
                     do k = 0, n
                         do j = 0, m
                             rhs_vf(c_idx)%sf(j, k, l) = &
-                                rhs_vf(c_idx)%sf(j, k, l) + 1d0/dx(j)* &
+                                rhs_vf(c_idx)%sf(j, k, l) + 1._wp/dx(j)* &
                                 q_prim_vf(c_idx)%sf(j, k, l)* &
                                 (flux_src_n(advxb)%sf(j, k, l) - &
                                  flux_src_n(advxb)%sf(j - 1, k, l))
@@ -1527,7 +1527,7 @@ contains
                         !$acc loop seq
                         do i = momxb, E_idx
                             rhs_vf(i)%sf(j, k, l) = &
-                                rhs_vf(i)%sf(j, k, l) + 1d0/dx(j)* &
+                                rhs_vf(i)%sf(j, k, l) + 1._wp/dx(j)* &
                                 (flux_src_n(i)%sf(j - 1, k, l) &
                                  - flux_src_n(i)%sf(j, k, l))
                         end do
@@ -1543,7 +1543,7 @@ contains
                     do k = 0, n
                         do j = 0, m
                             rhs_vf(c_idx)%sf(j, k, l) = &
-                                rhs_vf(c_idx)%sf(j, k, l) + 1d0/dy(k)* &
+                                rhs_vf(c_idx)%sf(j, k, l) + 1._wp/dy(k)* &
                                 q_prim_vf(c_idx)%sf(j, k, l)* &
                                 (flux_src_n(advxb)%sf(j, k, l) - &
                                  flux_src_n(advxb)%sf(j, k - 1, l))
@@ -1576,7 +1576,7 @@ contains
                             !$acc loop seq
                             do i = momxb, E_idx
                                 rhs_vf(i)%sf(j, 0, l) = &
-                                    rhs_vf(i)%sf(j, 0, l) + 1d0/(y_cc(1) - y_cc(-1))* &
+                                    rhs_vf(i)%sf(j, 0, l) + 1._wp/(y_cc(1) - y_cc(-1))* &
                                     (tau_Re_vf(i)%sf(j, -1, l) &
                                      - tau_Re_vf(i)%sf(j, 1, l))
                             end do
@@ -1592,7 +1592,7 @@ contains
                             !$acc loop seq
                             do i = momxb, E_idx
                                 rhs_vf(i)%sf(j, k, l) = &
-                                    rhs_vf(i)%sf(j, k, l) + 1d0/dy(k)* &
+                                    rhs_vf(i)%sf(j, k, l) + 1._wp/dy(k)* &
                                     (flux_src_n(i)%sf(j, k - 1, l) &
                                      - flux_src_n(i)%sf(j, k, l))
                             end do
@@ -1608,7 +1608,7 @@ contains
                             !$acc loop seq
                             do i = momxb, E_idx
                                 rhs_vf(i)%sf(j, k, l) = &
-                                    rhs_vf(i)%sf(j, k, l) + 1d0/dy(k)* &
+                                    rhs_vf(i)%sf(j, k, l) + 1._wp/dy(k)* &
                                     (flux_src_n(i)%sf(j, k - 1, l) &
                                      - flux_src_n(i)%sf(j, k, l))
                             end do
@@ -1629,7 +1629,7 @@ contains
                                 !$acc loop seq
                                 do i = momxb, E_idx
                                     rhs_vf(i)%sf(j, k, l) = &
-                                        rhs_vf(i)%sf(j, k, l) - 5d-1/y_cc(k)* &
+                                        rhs_vf(i)%sf(j, k, l) - 5e-1_wp/y_cc(k)* &
                                         (flux_src_n(i)%sf(j, k - 1, l) &
                                          + flux_src_n(i)%sf(j, k, l))
                                 end do
@@ -1644,7 +1644,7 @@ contains
                                 !$acc loop seq
                                 do i = momxb, E_idx
                                     rhs_vf(i)%sf(j, 0, l) = &
-                                        rhs_vf(i)%sf(j, 0, l) - 1d0/y_cc(0)* &
+                                        rhs_vf(i)%sf(j, 0, l) - 1._wp/y_cc(0)* &
                                         tau_Re_vf(i)%sf(j, 0, l)
                                 end do
                             end do
@@ -1659,7 +1659,7 @@ contains
                                 !$acc loop seq
                                 do i = momxb, E_idx
                                     rhs_vf(i)%sf(j, k, l) = &
-                                        rhs_vf(i)%sf(j, k, l) - 5d-1/y_cc(k)* &
+                                        rhs_vf(i)%sf(j, k, l) - 5e-1_wp/y_cc(k)* &
                                         (flux_src_n(i)%sf(j, k - 1, l) &
                                          + flux_src_n(i)%sf(j, k, l))
                                 end do
@@ -1678,7 +1678,7 @@ contains
                     do k = 0, n
                         do j = 0, m
                             rhs_vf(c_idx)%sf(j, k, l) = &
-                                rhs_vf(c_idx)%sf(j, k, l) + 1d0/dz(l)* &
+                                rhs_vf(c_idx)%sf(j, k, l) + 1._wp/dz(l)* &
                                 q_prim_vf(c_idx)%sf(j, k, l)* &
                                 (flux_src_n(advxb)%sf(j, k, l) - &
                                  flux_src_n(advxb)%sf(j, k, l - 1))
@@ -1694,7 +1694,7 @@ contains
                         !$acc loop seq
                         do i = momxb, E_idx
                             rhs_vf(i)%sf(j, k, l) = &
-                                rhs_vf(i)%sf(j, k, l) + 1d0/dz(l)* &
+                                rhs_vf(i)%sf(j, k, l) + 1._wp/dz(l)* &
                                 (flux_src_n(i)%sf(j, k, l - 1) &
                                  - flux_src_n(i)%sf(j, k, l))
                         end do
@@ -1708,12 +1708,12 @@ contains
                     do k = 0, n
                         do j = 0, m
                             rhs_vf(momxb + 1)%sf(j, k, l) = &
-                                rhs_vf(momxb + 1)%sf(j, k, l) + 5d-1* &
+                                rhs_vf(momxb + 1)%sf(j, k, l) + 5e-1_wp* &
                                 (flux_src_n(momxe)%sf(j, k, l - 1) &
                                  + flux_src_n(momxe)%sf(j, k, l))
 
                             rhs_vf(momxe)%sf(j, k, l) = &
-                                rhs_vf(momxe)%sf(j, k, l) - 5d-1* &
+                                rhs_vf(momxe)%sf(j, k, l) - 5e-1_wp* &
                                 (flux_src_n(momxb + 1)%sf(j, k, l - 1) &
                                  + flux_src_n(momxb + 1)%sf(j, k, l))
                         end do
@@ -1741,19 +1741,19 @@ contains
             !! function, liquid stiffness function (two variations of the last two
             !! ones), shear and volume Reynolds numbers and the Weber numbers
         !> @{
-        real(kind(0d0)) :: pres_relax
-        real(kind(0d0)), dimension(num_fluids) :: pres_K_init
-        real(kind(0d0)) :: f_pres
-        real(kind(0d0)) :: df_pres
-        real(kind(0d0)), dimension(num_fluids) :: rho_K_s
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho
-        real(kind(0d0)), dimension(num_fluids) :: alpha
-        real(kind(0d0)) :: sum_alpha
-        real(kind(0d0)) :: rho
-        real(kind(0d0)) :: dyn_pres
-        real(kind(0d0)) :: gamma
-        real(kind(0d0)) :: pi_inf
-        real(kind(0d0)), dimension(2) :: Re
+        real(wp) :: pres_relax
+        real(wp), dimension(num_fluids) :: pres_K_init
+        real(wp) :: f_pres
+        real(wp) :: df_pres
+        real(wp), dimension(num_fluids) :: rho_K_s
+        real(wp), dimension(num_fluids) :: alpha_rho
+        real(wp), dimension(num_fluids) :: alpha
+        real(wp) :: sum_alpha
+        real(wp) :: rho
+        real(wp) :: dyn_pres
+        real(wp) :: gamma
+        real(wp) :: pi_inf
+        real(wp), dimension(2) :: Re
 
         integer :: i, j, k, l, q, iter !< Generic loop iterators
         integer :: relax !< Relaxation procedure determination variable
@@ -1765,19 +1765,19 @@ contains
 
                     ! Numerical correction of the volume fractions
                     if (mpp_lim) then
-                        sum_alpha = 0d0
+                        sum_alpha = 0._wp
 
                         !$acc loop seq
                         do i = 1, num_fluids
-                            if ((q_cons_vf(i + contxb - 1)%sf(j, k, l) < 0d0) .or. &
-                                (q_cons_vf(i + advxb - 1)%sf(j, k, l) < 0d0)) then
-                                q_cons_vf(i + contxb - 1)%sf(j, k, l) = 0d0
-                                q_cons_vf(i + advxb - 1)%sf(j, k, l) = 0d0
-                                q_cons_vf(i + intxb - 1)%sf(j, k, l) = 0d0
+                            if ((q_cons_vf(i + contxb - 1)%sf(j, k, l) < 0._wp) .or. &
+                                (q_cons_vf(i + advxb - 1)%sf(j, k, l) < 0._wp)) then
+                                q_cons_vf(i + contxb - 1)%sf(j, k, l) = 0._wp
+                                q_cons_vf(i + advxb - 1)%sf(j, k, l) = 0._wp
+                                q_cons_vf(i + intxb - 1)%sf(j, k, l) = 0._wp
                             end if
 
-                            if (q_cons_vf(i + advxb - 1)%sf(j, k, l) > 1d0) &
-                                q_cons_vf(i + advxb - 1)%sf(j, k, l) = 1d0
+                            if (q_cons_vf(i + advxb - 1)%sf(j, k, l) > 1._wp) &
+                                q_cons_vf(i + advxb - 1)%sf(j, k, l) = 1._wp
                             sum_alpha = sum_alpha + q_cons_vf(i + advxb - 1)%sf(j, k, l)
                         end do
 
@@ -1794,12 +1794,12 @@ contains
 
                     !$acc loop seq
                     do i = 1, num_fluids
-                        if (q_cons_vf(i + advxb - 1)%sf(j, k, l) > (1d0 - sgm_eps)) relax = 0
+                        if (q_cons_vf(i + advxb - 1)%sf(j, k, l) > (1._wp - sgm_eps)) relax = 0
                     end do
 
                     if (relax == 1) then
                         ! Initial state
-                        pres_relax = 0d0
+                        pres_relax = 0._wp
 
                         !$acc loop seq
                         do i = 1, num_fluids
@@ -1809,38 +1809,38 @@ contains
                                      q_cons_vf(i + advxb - 1)%sf(j, k, l) &
                                      - pi_infs(i))/gammas(i)
 
-                                if (pres_K_init(i) <= -(1d0 - 1d-8)*pres_inf(i) + 1d-8) &
-                                    pres_K_init(i) = -(1d0 - 1d-8)*pres_inf(i) + 1d-8
+                                if (pres_K_init(i) <= -(1._wp - 1e-8_wp)*pres_inf(i) + 1e-8_wp) &
+                                    pres_K_init(i) = -(1._wp - 1e-8_wp)*pres_inf(i) + 1e-8_wp
                             else
-                                pres_K_init(i) = 0d0
+                                pres_K_init(i) = 0._wp
                             end if
                             pres_relax = pres_relax + q_cons_vf(i + advxb - 1)%sf(j, k, l)*pres_K_init(i)
                         end do
 
                         ! Iterative process for relaxed pressure determination
-                        f_pres = 1d-9
-                        df_pres = 1d9
+                        f_pres = 1e-9_wp
+                        df_pres = 1e9_wp
 
                         !$acc loop seq
                         do i = 1, num_fluids
-                            rho_K_s(i) = 0d0
+                            rho_K_s(i) = 0._wp
                         end do
 
                         !$acc loop seq
                         do iter = 0, 49
 
-                            if (DABS(f_pres) > 1d-10) then
+                            if (abs(f_pres) > 1e-10_wp) then
                                 pres_relax = pres_relax - f_pres/df_pres
 
                                 ! Physical pressure
                                 do i = 1, num_fluids
-                                    if (pres_relax <= -(1d0 - 1d-8)*pres_inf(i) + 1d-8) &
-                                        pres_relax = -(1d0 - 1d-8)*pres_inf(i) + 1d0
+                                    if (pres_relax <= -(1._wp - 1e-8_wp)*pres_inf(i) + 1e-8_wp) &
+                                        pres_relax = -(1._wp - 1e-8_wp)*pres_inf(i) + 1._wp
                                 end do
 
                                 ! Newton-Raphson method
-                                f_pres = -1d0
-                                df_pres = 0d0
+                                f_pres = -1._wp
+                                df_pres = 0._wp
 
                                 !$acc loop seq
                                 do i = 1, num_fluids
@@ -1848,7 +1848,7 @@ contains
                                         rho_K_s(i) = q_cons_vf(i + contxb - 1)%sf(j, k, l)/ &
                                                      max(q_cons_vf(i + advxb - 1)%sf(j, k, l), sgm_eps) &
                                                      *((pres_relax + pres_inf(i))/(pres_K_init(i) + &
-                                                                                   pres_inf(i)))**(1d0/gamma_min(i))
+                                                                                   pres_inf(i)))**(1._wp/gamma_min(i))
 
                                         f_pres = f_pres + q_cons_vf(i + contxb - 1)%sf(j, k, l) &
                                                  /rho_K_s(i)
@@ -1887,9 +1887,9 @@ contains
                     end do
 
                     if (bubbles) then
-                        rho = 0d0
-                        gamma = 0d0
-                        pi_inf = 0d0
+                        rho = 0._wp
+                        gamma = 0._wp
+                        pi_inf = 0._wp
 
                         if (mpp_lim .and. (model_eqns == 2) .and. (num_fluids > 2)) then
                             !$acc loop seq
@@ -1911,17 +1911,17 @@ contains
                             pi_inf = pi_infs(1)
                         end if
                     else
-                        rho = 0d0
-                        gamma = 0d0
-                        pi_inf = 0d0
+                        rho = 0._wp
+                        gamma = 0._wp
+                        pi_inf = 0._wp
 
-                        sum_alpha = 0d0
+                        sum_alpha = 0._wp
 
                         if (mpp_lim) then
                             !$acc loop seq
                             do i = 1, num_fluids
-                                alpha_rho(i) = max(0d0, alpha_rho(i))
-                                alpha(i) = min(max(0d0, alpha(i)), 1d0)
+                                alpha_rho(i) = max(0._wp, alpha_rho(i))
+                                alpha(i) = min(max(0._wp, alpha(i)), 1._wp)
                                 sum_alpha = sum_alpha + alpha(i)
                             end do
 
@@ -1941,24 +1941,24 @@ contains
                             do i = 1, 2
                                 Re(i) = dflt_real
 
-                                if (Re_size(i) > 0) Re(i) = 0d0
+                                if (Re_size(i) > 0) Re(i) = 0._wp
                                 !$acc loop seq
                                 do q = 1, Re_size(i)
                                     Re(i) = alpha(Re_idx(i, q))/Res(i, q) &
                                             + Re(i)
                                 end do
 
-                                Re(i) = 1d0/max(Re(i), sgm_eps)
+                                Re(i) = 1._wp/max(Re(i), sgm_eps)
 
                             end do
                         end if
                     end if
 
-                    dyn_pres = 0d0
+                    dyn_pres = 0._wp
 
                     !$acc loop seq
                     do i = momxb, momxe
-                        dyn_pres = dyn_pres + 5d-1*q_cons_vf(i)%sf(j, k, l)* &
+                        dyn_pres = dyn_pres + 5e-1_wp*q_cons_vf(i)%sf(j, k, l)* &
                                    q_cons_vf(i)%sf(j, k, l)/max(rho, sgm_eps)
                     end do
 
@@ -1991,8 +1991,8 @@ contains
                                                   norm_dir)
 
         type(scalar_field), dimension(iv%beg:iv%end), intent(in) :: v_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_x, vL_y, vL_z
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vR_x, vR_y, vR_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_x, vL_y, vL_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vR_x, vR_y, vR_z
         integer, intent(in) :: norm_dir
 
         integer :: weno_dir !< Coordinate direction of the WENO reconstruction
@@ -2044,8 +2044,8 @@ contains
                                                               norm_dir)
 
         type(scalar_field), dimension(iv%beg:iv%end), intent(in) :: v_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_x, vL_y, vL_z
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vR_x, vR_y, vR_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_x, vL_y, vL_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vR_x, vR_y, vR_z
         integer, intent(in) :: norm_dir
 
         integer :: recon_dir !< Coordinate direction of the WENO reconstruction
diff --git a/src/simulation/m_riemann_solvers.fpp b/src/simulation/m_riemann_solvers.fpp
index 7a9bdbb11..a7d1f3f3c 100644
--- a/src/simulation/m_riemann_solvers.fpp
+++ b/src/simulation/m_riemann_solvers.fpp
@@ -59,9 +59,10 @@ module m_riemann_solvers
     !! source terms, by using the left and right states given in qK_prim_rs_vf,
     !! dqK_prim_ds_vf where ds = dx, dy or dz.
     !> @{
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_rsx_vf, flux_src_rsx_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_rsy_vf, flux_src_rsy_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_rsz_vf, flux_src_rsz_vf
+
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_rsx_vf, flux_src_rsx_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_rsy_vf, flux_src_rsy_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_rsz_vf, flux_src_rsz_vf
     !$acc declare create( flux_rsx_vf, flux_src_rsx_vf, flux_rsy_vf,  &
     !$acc   flux_src_rsy_vf, flux_rsz_vf, flux_src_rsz_vf )
     !> @}
@@ -70,27 +71,29 @@ module m_riemann_solvers
     !! through the chosen Riemann problem solver by using the left and right
     !! states given in qK_prim_rs_vf. Currently 2D axisymmetric for inviscid only.
     !> @{
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_gsrc_rsx_vf !<
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_gsrc_rsy_vf !<
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: flux_gsrc_rsz_vf !<
+
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_gsrc_rsx_vf !<
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_gsrc_rsy_vf !<
+    real(wp), allocatable, dimension(:, :, :, :) :: flux_gsrc_rsz_vf !<
     !$acc declare create( flux_gsrc_rsx_vf, flux_gsrc_rsy_vf, flux_gsrc_rsz_vf )
     !> @}
 
     ! The cell-boundary values of the velocity. vel_src_rs_vf is determined as
     ! part of Riemann problem solution and is used to evaluate the source flux.
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: vel_src_rsx_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: vel_src_rsy_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: vel_src_rsz_vf
+
+    real(wp), allocatable, dimension(:, :, :, :) :: vel_src_rsx_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: vel_src_rsy_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: vel_src_rsz_vf
     !$acc declare create(vel_src_rsx_vf, vel_src_rsy_vf, vel_src_rsz_vf)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: mom_sp_rsx_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: mom_sp_rsy_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: mom_sp_rsz_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: mom_sp_rsx_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: mom_sp_rsy_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: mom_sp_rsz_vf
     !$acc declare create(mom_sp_rsx_vf, mom_sp_rsy_vf, mom_sp_rsz_vf)
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: Re_avg_rsx_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: Re_avg_rsy_vf
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: Re_avg_rsz_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: Re_avg_rsx_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: Re_avg_rsy_vf
+    real(wp), allocatable, dimension(:, :, :, :) :: Re_avg_rsz_vf
     !$acc declare create(Re_avg_rsx_vf, Re_avg_rsy_vf, Re_avg_rsz_vf)
 
     !> @name Indical bounds in the s1-, s2- and s3-directions
@@ -101,10 +104,10 @@ module m_riemann_solvers
 
     !$acc declare create(is1, is2, is3, isx, isy, isz)
 
-    real(kind(0d0)), allocatable, dimension(:) :: Gs
+    real(wp), allocatable, dimension(:) :: Gs
     !$acc declare create(Gs)
 
-    real(kind(0d0)), allocatable, dimension(:, :) :: Res
+    real(wp), allocatable, dimension(:, :) :: Res
     !$acc declare create(Res)
 
 contains
@@ -153,7 +156,7 @@ contains
                                 flux_gsrc_vf, &
                                 norm_dir, ix, iy, iz)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(INOUT) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(INOUT) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
         type(scalar_field), dimension(sys_size), intent(IN) :: q_prim_vf
 
         type(scalar_field), allocatable, dimension(:), intent(INOUT) :: qL_prim_vf, qR_prim_vf
@@ -274,7 +277,7 @@ contains
                                     flux_gsrc_vf, &
                                     norm_dir, ix, iy, iz)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
         type(scalar_field), dimension(sys_size), intent(in) :: q_prim_vf
 
         type(scalar_field), allocatable, dimension(:), intent(inout) :: qL_prim_vf, qR_prim_vf
@@ -293,44 +296,44 @@ contains
         integer, intent(in) :: norm_dir
         type(int_bounds_info), intent(in) :: ix, iy, iz
 
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho_L, alpha_rho_R
-        real(kind(0d0)) :: rho_L, rho_R
-        real(kind(0d0)), dimension(num_dims) :: vel_L, vel_R
-        real(kind(0d0)) :: pres_L, pres_R
-        real(kind(0d0)) :: E_L, E_R
-        real(kind(0d0)) :: H_L, H_R
-        real(kind(0d0)), dimension(num_fluids) :: alpha_L, alpha_R
-        real(kind(0d0)), dimension(num_species) :: Ys_L, Ys_R
-        real(kind(0d0)), dimension(num_species) :: Cp_iL, Cp_iR, Xs_L, Xs_R, Gamma_iL, Gamma_iR
-        real(kind(0d0)), dimension(num_species) :: Yi_avg, Phi_avg, h_iL, h_iR, h_avg_2
-        real(kind(0d0)) :: Cp_avg, Cv_avg, T_avg, eps, c_sum_Yi_Phi
-        real(kind(0d0)) :: T_L, T_R
-        real(kind(0d0)) :: Y_L, Y_R
-        real(kind(0d0)) :: MW_L, MW_R
-        real(kind(0d0)) :: R_gas_L, R_gas_R
-        real(kind(0d0)) :: Cp_L, Cp_R
-        real(kind(0d0)) :: Cv_L, Cv_R
-        real(kind(0d0)) :: Gamm_L, Gamm_R
-        real(kind(0d0)) :: gamma_L, gamma_R
-        real(kind(0d0)) :: pi_inf_L, pi_inf_R
-        real(kind(0d0)) :: qv_L, qv_R
-        real(kind(0d0)) :: c_L, c_R
-        real(kind(0d0)), dimension(6) :: tau_e_L, tau_e_R
-        real(kind(0d0)) :: G_L, G_R
-        real(kind(0d0)), dimension(2) :: Re_L, Re_R
-
-        real(kind(0d0)) :: rho_avg
-        real(kind(0d0)) :: H_avg
-        real(kind(0d0)) :: gamma_avg
-        real(kind(0d0)) :: c_avg
-
-        real(kind(0d0)) :: s_L, s_R, s_M, s_P, s_S
-        real(kind(0d0)) :: xi_M, xi_P
-
-        real(kind(0d0)) :: ptilde_L, ptilde_R
-        real(kind(0d0)) :: vel_L_rms, vel_R_rms, vel_avg_rms
-        real(kind(0d0)) :: Ms_L, Ms_R, pres_SL, pres_SR
-        real(kind(0d0)) :: alpha_L_sum, alpha_R_sum
+        real(wp), dimension(num_fluids) :: alpha_rho_L, alpha_rho_R
+        real(wp) :: rho_L, rho_R
+        real(wp), dimension(num_dims) :: vel_L, vel_R
+        real(wp) :: pres_L, pres_R
+        real(wp) :: E_L, E_R
+        real(wp) :: H_L, H_R
+        real(wp), dimension(num_fluids) :: alpha_L, alpha_R
+        real(wp), dimension(num_species) :: Ys_L, Ys_R
+        real(wp), dimension(num_species) :: Cp_iL, Cp_iR, Xs_L, Xs_R, Gamma_iL, Gamma_iR
+        real(wp), dimension(num_species) :: Yi_avg, Phi_avg, h_iL, h_iR, h_avg_2
+        real(wp) :: Cp_avg, Cv_avg, T_avg, eps, c_sum_Yi_Phi
+        real(wp) :: T_L, T_R
+        real(wp) :: Y_L, Y_R
+        real(wp) :: MW_L, MW_R
+        real(wp) :: R_gas_L, R_gas_R
+        real(wp) :: Cp_L, Cp_R
+        real(wp) :: Cv_L, Cv_R
+        real(wp) :: Gamm_L, Gamm_R
+        real(wp) :: gamma_L, gamma_R
+        real(wp) :: pi_inf_L, pi_inf_R
+        real(wp) :: qv_L, qv_R
+        real(wp) :: c_L, c_R
+        real(wp), dimension(6) :: tau_e_L, tau_e_R
+        real(wp) :: G_L, G_R
+        real(wp), dimension(2) :: Re_L, Re_R
+
+        real(wp) :: rho_avg
+        real(wp) :: H_avg
+        real(wp) :: gamma_avg
+        real(wp) :: c_avg
+
+        real(wp) :: s_L, s_R, s_M, s_P, s_S
+        real(wp) :: xi_M, xi_P
+
+        real(wp) :: ptilde_L, ptilde_R
+        real(wp) :: vel_L_rms, vel_R_rms, vel_avg_rms
+        real(wp) :: Ms_L, Ms_R, pres_SL, pres_SR
+        real(wp) :: alpha_L_sum, alpha_R_sum
 
         integer :: i, j, k, l, q !< Generic loop iterators
 
@@ -377,12 +380,12 @@ contains
                                 vel_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, contxe + i)
                             end do
 
-                            vel_L_rms = 0d0; vel_R_rms = 0d0
+                            vel_L_rms = 0._wp; vel_R_rms = 0._wp
 
                             !$acc loop seq
                             do i = 1, num_dims
-                                vel_L_rms = vel_L_rms + vel_L(i)**2d0
-                                vel_R_rms = vel_R_rms + vel_R(i)**2d0
+                                vel_L_rms = vel_L_rms + vel_L(i)**2._wp
+                                vel_R_rms = vel_R_rms + vel_R(i)**2._wp
                             end do
 
                             !$acc loop seq
@@ -394,24 +397,24 @@ contains
                             pres_L = qL_prim_rs${XYZ}$_vf(j, k, l, E_idx)
                             pres_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx)
 
-                            rho_L = 0d0
-                            gamma_L = 0d0
-                            pi_inf_L = 0d0
-                            qv_L = 0d0
+                            rho_L = 0._wp
+                            gamma_L = 0._wp
+                            pi_inf_L = 0._wp
+                            qv_L = 0._wp
 
-                            rho_R = 0d0
-                            gamma_R = 0d0
-                            pi_inf_R = 0d0
-                            qv_R = 0d0
+                            rho_R = 0._wp
+                            gamma_R = 0._wp
+                            pi_inf_R = 0._wp
+                            qv_R = 0._wp
 
-                            alpha_L_sum = 0d0
-                            alpha_R_sum = 0d0
+                            alpha_L_sum = 0._wp
+                            alpha_R_sum = 0._wp
 
                             if (mpp_lim) then
                                 !$acc loop seq
                                 do i = 1, num_fluids
-                                    alpha_rho_L(i) = max(0d0, alpha_rho_L(i))
-                                    alpha_L(i) = min(max(0d0, alpha_L(i)), 1d0)
+                                    alpha_rho_L(i) = max(0._wp, alpha_rho_L(i))
+                                    alpha_L(i) = min(max(0._wp, alpha_L(i)), 1._wp)
                                     alpha_L_sum = alpha_L_sum + alpha_L(i)
                                 end do
 
@@ -419,8 +422,8 @@ contains
 
                                 !$acc loop seq
                                 do i = 1, num_fluids
-                                    alpha_rho_R(i) = max(0d0, alpha_rho_R(i))
-                                    alpha_R(i) = min(max(0d0, alpha_R(i)), 1d0)
+                                    alpha_rho_R(i) = max(0._wp, alpha_rho_R(i))
+                                    alpha_R(i) = min(max(0._wp, alpha_R(i)), 1._wp)
                                     alpha_R_sum = alpha_R_sum + alpha_R(i)
                                 end do
 
@@ -445,7 +448,7 @@ contains
                                 do i = 1, 2
                                     Re_L(i) = dflt_real
 
-                                    if (Re_size(i) > 0) Re_L(i) = 0d0
+                                    if (Re_size(i) > 0) Re_L(i) = 0._wp
 
                                     !$acc loop seq
                                     do q = 1, Re_size(i)
@@ -453,7 +456,7 @@ contains
                                                   + Re_L(i)
                                     end do
 
-                                    Re_L(i) = 1d0/max(Re_L(i), sgm_eps)
+                                    Re_L(i) = 1._wp/max(Re_L(i), sgm_eps)
 
                                 end do
 
@@ -461,7 +464,7 @@ contains
                                 do i = 1, 2
                                     Re_R(i) = dflt_real
 
-                                    if (Re_size(i) > 0) Re_R(i) = 0d0
+                                    if (Re_size(i) > 0) Re_R(i) = 0._wp
 
                                     !$acc loop seq
                                     do q = 1, Re_size(i)
@@ -469,7 +472,7 @@ contains
                                                   + Re_R(i)
                                     end do
 
-                                    Re_R(i) = 1d0/max(Re_R(i), sgm_eps)
+                                    Re_R(i) = 1._wp/max(Re_R(i), sgm_eps)
                                 end do
                             end if
 
@@ -497,11 +500,11 @@ contains
 
                                 if (chem_params%gamma_method == 1) then
                                     ! gamma_method = 1: Ref. Section 2.3.1 Formulation of doi:10.7907/ZKW8-ES97.
-                                    Gamma_iL = Cp_iL/(Cp_iL - 1.0d0)
-                                    Gamma_iR = Cp_iR/(Cp_iR - 1.0d0)
+                                    Gamma_iL = Cp_iL/(Cp_iL - 1.0_wp)
+                                    Gamma_iR = Cp_iR/(Cp_iR - 1.0_wp)
 
-                                    gamma_L = sum(Xs_L(:)/(Gamma_iL(:) - 1.0d0))
-                                    gamma_R = sum(Xs_R(:)/(Gamma_iR(:) - 1.0d0))
+                                    gamma_L = sum(Xs_L(:)/(Gamma_iL(:) - 1.0_wp))
+                                    gamma_R = sum(Xs_R(:)/(Gamma_iR(:) - 1.0_wp))
                                 else if (chem_params%gamma_method == 2) then
                                     ! gamma_method = 2: c_p / c_v where c_p, c_v are specific heats.
                                     call get_mixture_specific_heat_cp_mass(T_L, Ys_L, Cp_L)
@@ -510,21 +513,21 @@ contains
                                     call get_mixture_specific_heat_cv_mass(T_R, Ys_R, Cv_R)
 
                                     Gamm_L = Cp_L/Cv_L
-                                    gamma_L = 1.0d0/(Gamm_L - 1.0d0)
+                                    gamma_L = 1.0_wp/(Gamm_L - 1.0_wp)
                                     Gamm_R = Cp_R/Cv_R
-                                    gamma_R = 1.0d0/(Gamm_R - 1.0d0)
+                                    gamma_R = 1.0_wp/(Gamm_R - 1.0_wp)
                                 end if
 
                                 call get_mixture_energy_mass(T_L, Ys_L, E_L)
                                 call get_mixture_energy_mass(T_R, Ys_R, E_R)
 
-                                E_L = rho_L*E_L + 5d-1*rho_L*vel_L_rms
-                                E_R = rho_R*E_R + 5d-1*rho_R*vel_R_rms
+                                E_L = rho_L*E_L + 5e-1*rho_L*vel_L_rms
+                                E_R = rho_R*E_R + 5e-1*rho_R*vel_R_rms
                                 H_L = (E_L + pres_L)/rho_L
                                 H_R = (E_R + pres_R)/rho_R
                             else
-                                E_L = gamma_L*pres_L + pi_inf_L + 5d-1*rho_L*vel_L_rms + qv_L
-                                E_R = gamma_R*pres_R + pi_inf_R + 5d-1*rho_R*vel_R_rms + qv_R
+                                E_L = gamma_L*pres_L + pi_inf_L + 5e-1*rho_L*vel_L_rms + qv_L
+                                E_R = gamma_R*pres_R + pi_inf_R + 5e-1*rho_R*vel_R_rms + qv_R
                                 H_L = (E_L + pres_L)/rho_L
                                 H_R = (E_R + pres_R)/rho_R
                             end if
@@ -536,8 +539,8 @@ contains
                                     tau_e_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, strxb - 1 + i)
                                 end do
 
-                                G_L = 0d0
-                                G_R = 0d0
+                                G_L = 0._wp
+                                G_R = 0._wp
 
                                 !$acc loop seq
                                 do i = 1, num_fluids
@@ -549,12 +552,12 @@ contains
                                     ! Elastic contribution to energy if G large enough
                                     !TODO take out if statement if stable without
                                     if ((G_L > 1000) .and. (G_R > 1000)) then
-                                        E_L = E_L + (tau_e_L(i)*tau_e_L(i))/(4d0*G_L)
-                                        E_R = E_R + (tau_e_R(i)*tau_e_R(i))/(4d0*G_R)
+                                        E_L = E_L + (tau_e_L(i)*tau_e_L(i))/(4._wp*G_L)
+                                        E_R = E_R + (tau_e_R(i)*tau_e_R(i))/(4._wp*G_R)
                                         ! Additional terms in 2D and 3D
                                         if ((i == 2) .or. (i == 4) .or. (i == 5)) then
-                                            E_L = E_L + (tau_e_L(i)*tau_e_L(i))/(4d0*G_L)
-                                            E_R = E_R + (tau_e_R(i)*tau_e_R(i))/(4d0*G_R)
+                                            E_L = E_L + (tau_e_L(i)*tau_e_L(i))/(4._wp*G_L)
+                                            E_R = E_R + (tau_e_R(i)*tau_e_R(i))/(4._wp*G_R)
                                         end if
                                     end if
                                 end do
@@ -563,10 +566,10 @@ contains
                             @:compute_average_state()
 
                             call s_compute_speed_of_sound(pres_L, rho_L, gamma_L, pi_inf_L, H_L, alpha_L, &
-                                                          vel_L_rms, 0d0, c_L)
+                                                          vel_L_rms, 0._wp, c_L)
 
                             call s_compute_speed_of_sound(pres_R, rho_R, gamma_R, pi_inf_R, H_R, alpha_R, &
-                                                          vel_R_rms, 0d0, c_R)
+                                                          vel_R_rms, 0._wp, c_R)
 
                             !> The computation of c_avg does not require all the variables, and therefore the non '_avg'
                             ! variables are placeholders to call the subroutine.
@@ -577,23 +580,23 @@ contains
                             if (viscous) then
                                 !$acc loop seq
                                 do i = 1, 2
-                                    Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2d0/(1d0/Re_L(i) + 1d0/Re_R(i))
+                                    Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2._wp/(1._wp/Re_L(i) + 1._wp/Re_R(i))
                                 end do
                             end if
 
                             if (wave_speeds == 1) then
                                 if (hypoelasticity) then
                                     s_L = min(vel_L(dir_idx(1)) - sqrt(c_L*c_L + &
-                                                                       (((4d0*G_L)/3d0) + &
+                                                                       (((4._wp*G_L)/3._wp) + &
                                                                         tau_e_L(dir_idx_tau(1)))/rho_L) &
                                               , vel_R(dir_idx(1)) - sqrt(c_R*c_R + &
-                                                                         (((4d0*G_R)/3d0) + &
+                                                                         (((4._wp*G_R)/3._wp) + &
                                                                           tau_e_R(dir_idx_tau(1)))/rho_R))
                                     s_R = max(vel_R(dir_idx(1)) + sqrt(c_R*c_R + &
-                                                                       (((4d0*G_R)/3d0) + &
+                                                                       (((4._wp*G_R)/3._wp) + &
                                                                         tau_e_R(dir_idx_tau(1)))/rho_R) &
                                               , vel_L(dir_idx(1)) + sqrt(c_L*c_L + &
-                                                                         (((4d0*G_L)/3d0) + &
+                                                                         (((4._wp*G_L)/3._wp) + &
                                                                           tau_e_L(dir_idx_tau(1)))/rho_L))
                                 else
                                     s_L = min(vel_L(dir_idx(1)) - c_L, vel_R(dir_idx(1)) - c_R)
@@ -607,35 +610,35 @@ contains
                                       /(rho_L*(s_L - vel_L(dir_idx(1))) - &
                                         rho_R*(s_R - vel_R(dir_idx(1))))
                             elseif (wave_speeds == 2) then
-                                pres_SL = 5d-1*(pres_L + pres_R + rho_avg*c_avg* &
-                                                (vel_L(dir_idx(1)) - &
-                                                 vel_R(dir_idx(1))))
+                                pres_SL = 5e-1_wp*(pres_L + pres_R + rho_avg*c_avg* &
+                                                   (vel_L(dir_idx(1)) - &
+                                                    vel_R(dir_idx(1))))
 
                                 pres_SR = pres_SL
 
-                                Ms_L = max(1d0, sqrt(1d0 + ((5d-1 + gamma_L)/(1d0 + gamma_L))* &
-                                                     (pres_SL/pres_L - 1d0)*pres_L/ &
-                                                     ((pres_L + pi_inf_L/(1d0 + gamma_L)))))
-                                Ms_R = max(1d0, sqrt(1d0 + ((5d-1 + gamma_R)/(1d0 + gamma_R))* &
-                                                     (pres_SR/pres_R - 1d0)*pres_R/ &
-                                                     ((pres_R + pi_inf_R/(1d0 + gamma_R)))))
+                                Ms_L = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_L)/(1._wp + gamma_L))* &
+                                                       (pres_SL/pres_L - 1._wp)*pres_L/ &
+                                                       ((pres_L + pi_inf_L/(1._wp + gamma_L)))))
+                                Ms_R = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_R)/(1._wp + gamma_R))* &
+                                                       (pres_SR/pres_R - 1._wp)*pres_R/ &
+                                                       ((pres_R + pi_inf_R/(1._wp + gamma_R)))))
 
                                 s_L = vel_L(dir_idx(1)) - c_L*Ms_L
                                 s_R = vel_R(dir_idx(1)) + c_R*Ms_R
 
-                                s_S = 5d-1*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
-                                            (pres_L - pres_R)/ &
-                                            (rho_avg*c_avg))
+                                s_S = 5e-1_wp*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
+                                               (pres_L - pres_R)/ &
+                                               (rho_avg*c_avg))
                             end if
 
-                            s_M = min(0d0, s_L); s_P = max(0d0, s_R)
+                            s_M = min(0._wp, s_L); s_P = max(0._wp, s_R)
 
-                            xi_M = (5d-1 + sign(5d-1, s_L)) &
-                                   + (5d-1 - sign(5d-1, s_L)) &
-                                   *(5d-1 + sign(5d-1, s_R))
-                            xi_P = (5d-1 - sign(5d-1, s_R)) &
-                                   + (5d-1 - sign(5d-1, s_L)) &
-                                   *(5d-1 + sign(5d-1, s_R))
+                            xi_M = (5e-1_wp + sign(5e-1_wp, s_L)) &
+                                   + (5e-1_wp - sign(5e-1_wp, s_L)) &
+                                   *(5e-1_wp + sign(5e-1_wp, s_R))
+                            xi_P = (5e-1_wp - sign(5e-1_wp, s_R)) &
+                                   + (5e-1_wp - sign(5e-1_wp, s_L)) &
+                                   *(5e-1_wp + sign(5e-1_wp, s_R))
 
                             ! Mass
                             !$acc loop seq
@@ -787,7 +790,7 @@ contains
                             if (bubbles) then
                                 ! From HLLC: Kills mass transport @ bubble gas density
                                 if (num_fluids > 1) then
-                                    flux_rs${XYZ}$_vf(j, k, l, contxe) = 0d0
+                                    flux_rs${XYZ}$_vf(j, k, l, contxe) = 0._wp
                                 end if
                             end if
 
@@ -801,7 +804,7 @@ contains
                                                                      - s_P*Y_L*rho_L*vel_L(dir_idx(1)) &
                                                                      + s_M*s_P*(Y_L*rho_L - Y_R*rho_R)) &
                                                                     /(s_M - s_P)
-                                    flux_src_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                    flux_src_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                 end do
                             end if
                         end do
@@ -888,7 +891,7 @@ contains
                                      flux_gsrc_vf, &
                                      norm_dir, ix, iy, iz)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
         type(scalar_field), dimension(sys_size), intent(in) :: q_prim_vf
 
         type(scalar_field), allocatable, dimension(:), intent(inout) :: qL_prim_vf, qR_prim_vf
@@ -907,56 +910,57 @@ contains
         integer, intent(in) :: norm_dir
         type(int_bounds_info), intent(in) :: ix, iy, iz
 
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho_L, alpha_rho_R
-        real(kind(0d0)) :: rho_L, rho_R
-        real(kind(0d0)), dimension(num_dims) :: vel_L, vel_R
-        real(kind(0d0)) :: pres_L, pres_R
-        real(kind(0d0)) :: E_L, E_R
-        real(kind(0d0)) :: H_L, H_R
-        real(kind(0d0)), dimension(num_fluids) :: alpha_L, alpha_R
-        real(kind(0d0)), dimension(num_species) :: Ys_L, Ys_R, Xs_L, Xs_R, Gamma_iL, Gamma_iR, Cp_iL, Cp_iR
-        real(kind(0d0)), dimension(num_species) :: Yi_avg, Phi_avg, h_iL, h_iR, h_avg_2
-        real(kind(0d0)) :: Cp_avg, Cv_avg, T_avg, c_sum_Yi_Phi, eps
-        real(kind(0d0)) :: T_L, T_R
-        real(kind(0d0)) :: MW_L, MW_R
-        real(kind(0d0)) :: R_gas_L, R_gas_R
-        real(kind(0d0)) :: Cp_L, Cp_R
-        real(kind(0d0)) :: Cv_L, Cv_R
-        real(kind(0d0)) :: Gamm_L, Gamm_R
-        real(kind(0d0)) :: Y_L, Y_R
-        real(kind(0d0)) :: gamma_L, gamma_R
-        real(kind(0d0)) :: pi_inf_L, pi_inf_R
-        real(kind(0d0)) :: qv_L, qv_R
-        real(kind(0d0)) :: c_L, c_R
-        real(kind(0d0)), dimension(2) :: Re_L, Re_R
-
-        real(kind(0d0)) :: rho_avg
-        real(kind(0d0)) :: H_avg
-        real(kind(0d0)) :: gamma_avg
-        real(kind(0d0)) :: c_avg
-
-        real(kind(0d0)) :: s_L, s_R, s_M, s_P, s_S
-        real(kind(0d0)) :: xi_L, xi_R !< Left and right wave speeds functions
-        real(kind(0d0)) :: xi_M, xi_P
-
-        real(kind(0d0)) :: nbub_L, nbub_R
-        real(kind(0d0)), dimension(nb) :: R0_L, R0_R
-        real(kind(0d0)), dimension(nb) :: V0_L, V0_R
-        real(kind(0d0)), dimension(nb) :: P0_L, P0_R
-        real(kind(0d0)), dimension(nb) :: pbw_L, pbw_R
-        real(kind(0d0)) :: ptilde_L, ptilde_R
-
-        real(kind(0d0)) :: alpha_L_sum, alpha_R_sum, nbub_L_denom, nbub_R_denom
-
-        real(kind(0d0)) :: PbwR3Lbar, Pbwr3Rbar
-        real(kind(0d0)) :: R3Lbar, R3Rbar
-        real(kind(0d0)) :: R3V2Lbar, R3V2Rbar
-
-        real(kind(0d0)) :: vel_L_rms, vel_R_rms, vel_avg_rms
-        real(kind(0d0)) :: vel_L_tmp, vel_R_tmp
-        real(kind(0d0)) :: rho_Star, E_Star, p_Star, p_K_Star
-        real(kind(0d0)) :: pres_SL, pres_SR, Ms_L, Ms_R
-        real(kind(0d0)) :: zcoef, pcorr !< low Mach number correction
+        real(wp), dimension(num_fluids) :: alpha_rho_L, alpha_rho_R
+        real(wp) :: rho_L, rho_R
+        real(wp), dimension(num_dims) :: vel_L, vel_R
+        real(wp) :: pres_L, pres_R
+        real(wp) :: E_L, E_R
+        real(wp) :: H_L, H_R
+        real(wp), dimension(num_fluids) :: alpha_L, alpha_R
+        real(wp), dimension(num_species) :: Ys_L, Ys_R, Xs_L, Xs_R, Gamma_iL, Gamma_iR, Cp_iL, Cp_iR
+        real(wp), dimension(num_species) :: Yi_avg, Phi_avg, h_iL, h_iR, h_avg_2
+        real(wp) :: Cp_avg, Cv_avg, T_avg, c_sum_Yi_Phi, eps
+        real(wp) :: T_L, T_R
+        real(wp) :: MW_L, MW_R
+        real(wp) :: R_gas_L, R_gas_R
+        real(wp) :: Cp_L, Cp_R
+        real(wp) :: Cv_L, Cv_R
+        real(wp) :: Gamm_L, Gamm_R
+        real(wp) :: Y_L, Y_R
+        real(wp) :: gamma_L, gamma_R
+        real(wp) :: pi_inf_L, pi_inf_R
+        real(wp) :: qv_L, qv_R
+        real(wp) :: c_L, c_R
+        real(wp), dimension(2) :: Re_L, Re_R
+
+        real(wp) :: rho_avg
+        real(wp) :: H_avg
+        real(wp) :: gamma_avg
+        real(wp) :: c_avg
+
+        real(wp) :: s_L, s_R, s_M, s_P, s_S
+        real(wp) :: xi_L, xi_R !< Left and right wave speeds functions
+        real(wp) :: xi_M, xi_P
+
+        real(wp) :: nbub_L, nbub_R
+        real(wp), dimension(nb) :: R0_L, R0_R
+        real(wp), dimension(nb) :: V0_L, V0_R
+        real(wp), dimension(nb) :: P0_L, P0_R
+        real(wp), dimension(nb) :: pbw_L, pbw_R
+        real(wp) :: ptilde_L, ptilde_R
+
+        real(wp) :: alpha_L_sum, alpha_R_sum, nbub_L_denom, nbub_R_denom
+
+        real(wp) :: PbwR3Lbar, Pbwr3Rbar
+        real(wp) :: R3Lbar, R3Rbar
+        real(wp) :: R3V2Lbar, R3V2Rbar
+
+        real(wp) :: vel_L_rms, vel_R_rms, vel_avg_rms
+        real(wp) :: vel_L_tmp, vel_R_tmp
+        real(wp) :: rho_Star, E_Star, p_Star, p_K_Star
+        real(wp) :: pres_SL, pres_SR, Ms_L, Ms_R
+        real(wp) :: zcoef, pcorr !< low Mach number correction
+
         integer :: i, j, k, l, q !< Generic loop iterators
         integer :: idx1, idxi
 
@@ -997,37 +1001,37 @@ contains
                         do k = is2%beg, is2%end
                             do j = is1%beg, is1%end
 
-                                vel_L_rms = 0d0; vel_R_rms = 0d0
+                                vel_L_rms = 0._wp; vel_R_rms = 0._wp
 
                                 !$acc loop seq
                                 do i = 1, num_dims
                                     vel_L(i) = qL_prim_rs${XYZ}$_vf(j, k, l, contxe + i)
                                     vel_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, contxe + i)
-                                    vel_L_rms = vel_L_rms + vel_L(i)**2d0
-                                    vel_R_rms = vel_R_rms + vel_R(i)**2d0
+                                    vel_L_rms = vel_L_rms + vel_L(i)**2._wp
+                                    vel_R_rms = vel_R_rms + vel_R(i)**2._wp
                                 end do
 
                                 pres_L = qL_prim_rs${XYZ}$_vf(j, k, l, E_idx)
                                 pres_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx)
 
-                                rho_L = 0d0
-                                gamma_L = 0d0
-                                pi_inf_L = 0d0
-                                qv_L = 0d0
+                                rho_L = 0._wp
+                                gamma_L = 0._wp
+                                pi_inf_L = 0._wp
+                                qv_L = 0._wp
 
-                                rho_R = 0d0
-                                gamma_R = 0d0
-                                pi_inf_R = 0d0
-                                qv_R = 0d0
+                                rho_R = 0._wp
+                                gamma_R = 0._wp
+                                pi_inf_R = 0._wp
+                                qv_R = 0._wp
 
-                                alpha_L_sum = 0d0
-                                alpha_R_sum = 0d0
+                                alpha_L_sum = 0._wp
+                                alpha_R_sum = 0._wp
 
                                 if (mpp_lim) then
                                     !$acc loop seq
                                     do i = 1, num_fluids
-                                        qL_prim_rs${XYZ}$_vf(j, k, l, i) = max(0d0, qL_prim_rs${XYZ}$_vf(j, k, l, i))
-                                        qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i) = min(max(0d0, qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i)), 1d0)
+                                        qL_prim_rs${XYZ}$_vf(j, k, l, i) = max(0._wp, qL_prim_rs${XYZ}$_vf(j, k, l, i))
+                                        qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i) = min(max(0._wp, qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i)), 1._wp)
                                         alpha_L_sum = alpha_L_sum + qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i)
                                     end do
 
@@ -1038,8 +1042,8 @@ contains
 
                                     !$acc loop seq
                                     do i = 1, num_fluids
-                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) = max(0d0, qR_prim_rs${XYZ}$_vf(j + 1, k, l, i))
-                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i) = min(max(0d0, qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)), 1d0)
+                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) = max(0._wp, qR_prim_rs${XYZ}$_vf(j + 1, k, l, i))
+                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i) = min(max(0._wp, qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)), 1._wp)
                                         alpha_R_sum = alpha_R_sum + qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)
                                     end do
 
@@ -1070,7 +1074,7 @@ contains
                                     do i = 1, 2
                                         Re_L(i) = dflt_real
 
-                                        if (Re_size(i) > 0) Re_L(i) = 0d0
+                                        if (Re_size(i) > 0) Re_L(i) = 0._wp
 
                                         !$acc loop seq
                                         do q = 1, Re_size(i)
@@ -1078,7 +1082,7 @@ contains
                                                       + Re_L(i)
                                         end do
 
-                                        Re_L(i) = 1d0/max(Re_L(i), sgm_eps)
+                                        Re_L(i) = 1._wp/max(Re_L(i), sgm_eps)
 
                                     end do
 
@@ -1086,7 +1090,7 @@ contains
                                     do i = 1, 2
                                         Re_R(i) = dflt_real
 
-                                        if (Re_size(i) > 0) Re_R(i) = 0d0
+                                        if (Re_size(i) > 0) Re_R(i) = 0._wp
 
                                         !$acc loop seq
                                         do q = 1, Re_size(i)
@@ -1094,13 +1098,13 @@ contains
                                                       + Re_R(i)
                                         end do
 
-                                        Re_R(i) = 1d0/max(Re_R(i), sgm_eps)
+                                        Re_R(i) = 1._wp/max(Re_R(i), sgm_eps)
                                     end do
                                 end if
 
-                                E_L = gamma_L*pres_L + pi_inf_L + 5d-1*rho_L*vel_L_rms + qv_L
+                                E_L = gamma_L*pres_L + pi_inf_L + 5e-1_wp*rho_L*vel_L_rms + qv_L
 
-                                E_R = gamma_R*pres_R + pi_inf_R + 5d-1*rho_R*vel_R_rms + qv_R
+                                E_R = gamma_R*pres_R + pi_inf_R + 5e-1_wp*rho_R*vel_R_rms + qv_R
 
                                 H_L = (E_L + pres_L)/rho_L
                                 H_R = (E_R + pres_R)/rho_R
@@ -1108,21 +1112,21 @@ contains
                                 @:compute_average_state()
 
                                 call s_compute_speed_of_sound(pres_L, rho_L, gamma_L, pi_inf_L, H_L, alpha_L, &
-                                                              vel_L_rms, 0d0, c_L)
+                                                              vel_L_rms, 0._wp, c_L)
 
                                 call s_compute_speed_of_sound(pres_R, rho_R, gamma_R, pi_inf_R, H_R, alpha_R, &
-                                                              vel_R_rms, 0d0, c_R)
+                                                              vel_R_rms, 0._wp, c_R)
 
                                 !> The computation of c_avg does not require all the variables, and therefore the non '_avg'
                                 ! variables are placeholders to call the subroutine.
 
                                 call s_compute_speed_of_sound(pres_R, rho_avg, gamma_avg, pi_inf_R, H_avg, alpha_R, &
-                                                              vel_avg_rms, 0d0, c_avg)
+                                                              vel_avg_rms, 0._wp, c_avg)
 
                                 if (viscous) then
                                     !$acc loop seq
                                     do i = 1, 2
-                                        Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2d0/(1d0/Re_L(i) + 1d0/Re_R(i))
+                                        Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2._wp/(1._wp/Re_L(i) + 1._wp/Re_R(i))
                                     end do
                                 end if
 
@@ -1137,28 +1141,28 @@ contains
                                           /(rho_L*(s_L - vel_L(dir_idx(1))) - &
                                             rho_R*(s_R - vel_R(dir_idx(1))))
                                 elseif (wave_speeds == 2) then
-                                    pres_SL = 5d-1*(pres_L + pres_R + rho_avg*c_avg* &
-                                                    (vel_L(dir_idx(1)) - &
-                                                     vel_R(dir_idx(1))))
+                                    pres_SL = 5e-1_wp*(pres_L + pres_R + rho_avg*c_avg* &
+                                                       (vel_L(dir_idx(1)) - &
+                                                        vel_R(dir_idx(1))))
 
                                     pres_SR = pres_SL
 
-                                    Ms_L = max(1d0, sqrt(1d0 + ((5d-1 + gamma_L)/(1d0 + gamma_L))* &
-                                                         (pres_SL/pres_L - 1d0)*pres_L/ &
-                                                         ((pres_L + pi_inf_L/(1d0 + gamma_L)))))
-                                    Ms_R = max(1d0, sqrt(1d0 + ((5d-1 + gamma_R)/(1d0 + gamma_R))* &
-                                                         (pres_SR/pres_R - 1d0)*pres_R/ &
-                                                         ((pres_R + pi_inf_R/(1d0 + gamma_R)))))
+                                    Ms_L = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_L)/(1._wp + gamma_L))* &
+                                                           (pres_SL/pres_L - 1._wp)*pres_L/ &
+                                                           ((pres_L + pi_inf_L/(1._wp + gamma_L)))))
+                                    Ms_R = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_R)/(1._wp + gamma_R))* &
+                                                           (pres_SR/pres_R - 1._wp)*pres_R/ &
+                                                           ((pres_R + pi_inf_R/(1._wp + gamma_R)))))
 
                                     s_L = vel_L(dir_idx(1)) - c_L*Ms_L
                                     s_R = vel_R(dir_idx(1)) + c_R*Ms_R
 
-                                    s_S = 5d-1*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
-                                                (pres_L - pres_R)/ &
-                                                (rho_avg*c_avg))
+                                    s_S = 5e-1_wp*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
+                                                   (pres_L - pres_R)/ &
+                                                   (rho_avg*c_avg))
                                 end if
 
-                                if (s_L >= 0d0) then
+                                if (s_L >= 0._wp) then
                                     p_Star = pres_L ! Only useful to recalculate the radial momentum geometric source flux
                                     !$acc loop seq
                                     do i = 1, num_fluids
@@ -1191,7 +1195,7 @@ contains
                                     end if
 
                                     ! Compute right solution state
-                                else if (s_R <= 0d0) then
+                                else if (s_R <= 0._wp) then
                                     p_Star = pres_R
                                     ! Only useful to recalculate the radial momentum geometric source flux
                                     !$acc loop seq
@@ -1225,7 +1229,7 @@ contains
                                     end if
 
                                     ! Compute left star solution state
-                                else if (s_S >= 0d0) then
+                                else if (s_S >= 0._wp) then
                                     xi_L = (s_L - vel_L(dir_idx(1)))/(s_L - s_S)
                                     rho_Star = rho_L*xi_L
                                     E_Star = xi_L*(E_L + (s_S - vel_L(dir_idx(1)))* &
@@ -1233,8 +1237,8 @@ contains
                                     p_Star = rho_L*(s_L - vel_L(dir_idx(1)))*(s_S - vel_L(dir_idx(1))) + pres_L
                                     !$acc loop seq
                                     do i = 1, num_fluids
-                                        p_K_Star = (pres_L + pi_infs(i)/(1d0 + gammas(i)))* &
-                                                   xi_L**(1d0/gammas(i) + 1d0) - pi_infs(i)/(1d0 + gammas(i))
+                                        p_K_Star = (pres_L + pi_infs(i)/(1._wp + gammas(i)))* &
+                                                   xi_L**(1._wp/gammas(i) + 1._wp) - pi_infs(i)/(1._wp + gammas(i))
 
                                         flux_rs${XYZ}$_vf(j, k, l, i + advxb - 1) = &
                                             qL_prim_rs${XYZ}$_vf(j, k, l, i + advxb - 1)*s_S
@@ -1252,7 +1256,7 @@ contains
                                     do i = 1, num_dims
                                         flux_rs${XYZ}$_vf(j, k, l, momxb - 1 + dir_idx(i)) = &
                                             rho_Star*s_S*(s_S*dir_flg(dir_idx(i)) + vel_L(dir_idx(i))* &
-                                                          (1d0 - dir_flg(dir_idx(i)))) + dir_flg(dir_idx(i))*p_Star
+                                                          (1._wp - dir_flg(dir_idx(i)))) + dir_flg(dir_idx(i))*p_Star
 
                                         vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(i)) = vel_L(dir_idx(i)) + &
                                                                                     dir_flg(dir_idx(i))*(s_S*xi_L - vel_L(dir_idx(i)))
@@ -1277,8 +1281,8 @@ contains
                                     p_Star = rho_R*(s_R - vel_R(dir_idx(1)))*(s_S - vel_R(dir_idx(1))) + pres_R
                                     !$acc loop seq
                                     do i = 1, num_fluids
-                                        p_K_Star = (pres_R + pi_infs(i)/(1d0 + gammas(i)))* &
-                                                   xi_R**(1d0/gammas(i) + 1d0) - pi_infs(i)/(1d0 + gammas(i))
+                                        p_K_Star = (pres_R + pi_infs(i)/(1._wp + gammas(i)))* &
+                                                   xi_R**(1._wp/gammas(i) + 1._wp) - pi_infs(i)/(1._wp + gammas(i))
 
                                         flux_rs${XYZ}$_vf(j, k, l, i + advxb - 1) = &
                                             qR_prim_rs${XYZ}$_vf(j + 1, k, l, i + advxb - 1)*s_S
@@ -1295,7 +1299,7 @@ contains
                                     !$acc loop seq
                                     do i = 1, num_dims
                                         flux_rs${XYZ}$_vf(j, k, l, momxb - 1 + dir_idx(i)) = rho_Star*s_S* &
-                                                                                             (s_S*dir_flg(dir_idx(i)) + vel_R(dir_idx(i))*(1d0 - dir_flg(dir_idx(i)))) + &
+                                                                                             (s_S*dir_flg(dir_idx(i)) + vel_R(dir_idx(i))*(1._wp - dir_flg(dir_idx(i)))) + &
                                                                                              dir_flg(dir_idx(i))*p_Star
 
                                         vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(i)) = vel_R(dir_idx(i)) + &
@@ -1331,7 +1335,7 @@ contains
                                     ! Geometrical source of the void fraction(s) is zero
                                     !$acc loop seq
                                     do i = advxb, advxe
-                                        flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                        flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                     end do
                                 end if
 
@@ -1357,11 +1361,11 @@ contains
                                     vel_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, contxe + i)
                                 end do
 
-                                vel_L_rms = 0d0; vel_R_rms = 0d0
+                                vel_L_rms = 0._wp; vel_R_rms = 0._wp
                                 !$acc loop seq
                                 do i = 1, num_dims
-                                    vel_L_rms = vel_L_rms + vel_L(i)**2d0
-                                    vel_R_rms = vel_R_rms + vel_R(i)**2d0
+                                    vel_L_rms = vel_L_rms + vel_L(i)**2._wp
+                                    vel_R_rms = vel_R_rms + vel_R(i)**2._wp
                                 end do
 
                                 !$acc loop seq
@@ -1373,10 +1377,10 @@ contains
                                 pres_L = qL_prim_rs${XYZ}$_vf(j, k, l, E_idx)
                                 pres_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx)
 
-                                rho_L = 0d0
-                                gamma_L = 0d0
-                                pi_inf_L = 0d0
-                                qv_L = 0d0
+                                rho_L = 0._wp
+                                gamma_L = 0._wp
+                                pi_inf_L = 0._wp
+                                qv_L = 0._wp
                                 !$acc loop seq
                                 do i = 1, num_fluids
                                     rho_L = rho_L + alpha_rho_L(i)
@@ -1385,10 +1389,10 @@ contains
                                     qv_L = qv_L + alpha_rho_L(i)*qvs(i)
                                 end do
 
-                                rho_R = 0d0
-                                gamma_R = 0d0
-                                pi_inf_R = 0d0
-                                qv_R = 0d0
+                                rho_R = 0._wp
+                                gamma_R = 0._wp
+                                pi_inf_R = 0._wp
+                                qv_R = 0._wp
                                 !$acc loop seq
                                 do i = 1, num_fluids
                                     rho_R = rho_R + alpha_rho_R(i)
@@ -1397,9 +1401,9 @@ contains
                                     qv_R = qv_R + alpha_rho_R(i)*qvs(i)
                                 end do
 
-                                E_L = gamma_L*pres_L + pi_inf_L + 5d-1*rho_L*vel_L_rms + qv_L
+                                E_L = gamma_L*pres_L + pi_inf_L + 5e-1_wp*rho_L*vel_L_rms + qv_L
 
-                                E_R = gamma_R*pres_R + pi_inf_R + 5d-1*rho_R*vel_R_rms + qv_R
+                                E_R = gamma_R*pres_R + pi_inf_R + 5e-1_wp*rho_R*vel_R_rms + qv_R
 
                                 H_L = (E_L + pres_L)/rho_L
                                 H_R = (E_R + pres_R)/rho_R
@@ -1407,16 +1411,16 @@ contains
                                 @:compute_average_state()
 
                                 call s_compute_speed_of_sound(pres_L, rho_L, gamma_L, pi_inf_L, H_L, alpha_L, &
-                                                              vel_L_rms, 0d0, c_L)
+                                                              vel_L_rms, 0._wp, c_L)
 
                                 call s_compute_speed_of_sound(pres_R, rho_R, gamma_R, pi_inf_R, H_R, alpha_R, &
-                                                              vel_R_rms, 0d0, c_R)
+                                                              vel_R_rms, 0._wp, c_R)
 
                                 !> The computation of c_avg does not require all the variables, and therefore the non '_avg'
                                 ! variables are placeholders to call the subroutine.
 
                                 call s_compute_speed_of_sound(pres_R, rho_avg, gamma_avg, pi_inf_R, H_avg, alpha_R, &
-                                                              vel_avg_rms, 0d0, c_avg)
+                                                              vel_avg_rms, 0._wp, c_avg)
 
                                 if (wave_speeds == 1) then
                                     s_L = min(vel_L(dir_idx(1)) - c_L, vel_R(dir_idx(1)) - c_R)
@@ -1429,30 +1433,30 @@ contains
                                           /(rho_L*(s_L - vel_L(dir_idx(1))) - &
                                             rho_R*(s_R - vel_R(dir_idx(1))))
                                 elseif (wave_speeds == 2) then
-                                    pres_SL = 5d-1*(pres_L + pres_R + rho_avg*c_avg* &
-                                                    (vel_L(dir_idx(1)) - &
-                                                     vel_R(dir_idx(1))))
+                                    pres_SL = 5e-1_wp*(pres_L + pres_R + rho_avg*c_avg* &
+                                                       (vel_L(dir_idx(1)) - &
+                                                        vel_R(dir_idx(1))))
 
                                     pres_SR = pres_SL
 
-                                    Ms_L = max(1d0, sqrt(1d0 + ((5d-1 + gamma_L)/(1d0 + gamma_L))* &
-                                                         (pres_SL/pres_L - 1d0)*pres_L/ &
-                                                         ((pres_L + pi_inf_L/(1d0 + gamma_L)))))
-                                    Ms_R = max(1d0, sqrt(1d0 + ((5d-1 + gamma_R)/(1d0 + gamma_R))* &
-                                                         (pres_SR/pres_R - 1d0)*pres_R/ &
-                                                         ((pres_R + pi_inf_R/(1d0 + gamma_R)))))
+                                    Ms_L = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_L)/(1._wp + gamma_L))* &
+                                                           (pres_SL/pres_L - 1._wp)*pres_L/ &
+                                                           ((pres_L + pi_inf_L/(1._wp + gamma_L)))))
+                                    Ms_R = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_R)/(1._wp + gamma_R))* &
+                                                           (pres_SR/pres_R - 1._wp)*pres_R/ &
+                                                           ((pres_R + pi_inf_R/(1._wp + gamma_R)))))
 
                                     s_L = vel_L(dir_idx(1)) - c_L*Ms_L
                                     s_R = vel_R(dir_idx(1)) + c_R*Ms_R
 
-                                    s_S = 5d-1*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
-                                                (pres_L - pres_R)/ &
-                                                (rho_avg*c_avg))
+                                    s_S = 5e-1_wp*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
+                                                   (pres_L - pres_R)/ &
+                                                   (rho_avg*c_avg))
                                 end if
 
                                 ! follows Einfeldt et al.
                                 ! s_M/P = min/max(0.,s_L/R)
-                                s_M = min(0d0, s_L); s_P = max(0d0, s_R)
+                                s_M = min(0._wp, s_L); s_P = max(0._wp, s_R)
 
                                 ! goes with q_star_L/R = xi_L/R * (variable)
                                 ! xi_L/R = ( ( s_L/R - u_L/R )/(s_L/R - s_star) )
@@ -1461,16 +1465,16 @@ contains
 
                                 ! goes with numerical velocity in x/y/z directions
                                 ! xi_P/M = 0.5 +/m sgn(0.5,s_star)
-                                xi_M = (5d-1 + sign(5d-1, s_S))
-                                xi_P = (5d-1 - sign(5d-1, s_S))
+                                xi_M = (5e-1_wp + sign(5e-1_wp, s_S))
+                                xi_P = (5e-1_wp - sign(5e-1_wp, s_S))
 
                                 !$acc loop seq
                                 do i = 1, contxe
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*alpha_rho_L(i) &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*alpha_rho_R(i) &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 ! Momentum flux.
@@ -1481,13 +1485,13 @@ contains
                                         xi_M*(rho_L*(vel_L(dir_idx(1))* &
                                                      vel_L(dir_idx(i)) + &
                                                      s_M*(xi_L*(dir_flg(dir_idx(i))*s_S + &
-                                                                (1d0 - dir_flg(dir_idx(i)))* &
+                                                                (1._wp - dir_flg(dir_idx(i)))* &
                                                                 vel_L(dir_idx(i))) - vel_L(dir_idx(i)))) + &
                                               dir_flg(dir_idx(i))*pres_L) &
                                         + xi_P*(rho_R*(vel_R(dir_idx(1))* &
                                                        vel_R(dir_idx(i)) + &
                                                        s_P*(xi_R*(dir_flg(dir_idx(i))*s_S + &
-                                                                  (1d0 - dir_flg(dir_idx(i)))* &
+                                                                  (1._wp - dir_flg(dir_idx(i)))* &
                                                                   vel_R(dir_idx(i))) - vel_R(dir_idx(i)))) + &
                                                 dir_flg(dir_idx(i))*pres_R)
                                 end do
@@ -1498,28 +1502,28 @@ contains
                                     do i = 1, num_dims
                                         flux_rs${XYZ}$_vf(j, k, l, contxe + dir_idx(i)) = &
                                             flux_rs${XYZ}$_vf(j, k, l, contxe + dir_idx(i)) + &
-                                            xi_M*(dir_flg(dir_idx(i))*(-1d0*ptilde_L)) &
-                                            + xi_P*(dir_flg(dir_idx(i))*(-1d0*ptilde_R))
+                                            xi_M*(dir_flg(dir_idx(i))*(-1._wp*ptilde_L)) &
+                                            + xi_P*(dir_flg(dir_idx(i))*(-1._wp*ptilde_R))
                                     end do
                                 end if
 
-                                flux_rs${XYZ}$_vf(j, k, l, E_idx) = 0.d0
+                                flux_rs${XYZ}$_vf(j, k, l, E_idx) = 0._wp
 
                                 !$acc loop seq
                                 do i = alf_idx, alf_idx !only advect the void fraction
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 ! Source for volume fraction advection equation
                                 !$acc loop seq
                                 do i = 1, num_dims
 
-                                    vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(i)) = 0d0
-                                    !IF ( (model_eqns == 4) .or. (num_fluids==1) ) vel_src_rs_vf(dir_idx(i))%sf(j,k,l) = 0d0
+                                    vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(i)) = 0._wp
+                                    !IF ( (model_eqns == 4) .or. (num_fluids==1) ) vel_src_rs_vf(dir_idx(i))%sf(j,k,l) = 0._wp
                                 end do
 
                                 flux_src_rs${XYZ}$_vf(j, k, l, advxb) = vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(1))
@@ -1530,9 +1534,9 @@ contains
                                     do i = bubxb, bubxe
                                         flux_rs${XYZ}$_vf(j, k, l, i) = &
                                             xi_M*nbub_L*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                            *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                            *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                             + xi_P*nbub_R*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                            *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                            *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                     end do
                                 end if
 
@@ -1550,17 +1554,17 @@ contains
                                             xi_M*(rho_L*(vel_L(dir_idx(1))* &
                                                          vel_L(dir_idx(1)) + &
                                                          s_M*(xi_L*(dir_flg(dir_idx(1))*s_S + &
-                                                                    (1d0 - dir_flg(dir_idx(1)))* &
+                                                                    (1._wp - dir_flg(dir_idx(1)))* &
                                                                     vel_L(dir_idx(1))) - vel_L(dir_idx(1))))) &
                                             + xi_P*(rho_R*(vel_R(dir_idx(1))* &
                                                            vel_R(dir_idx(1)) + &
                                                            s_P*(xi_R*(dir_flg(dir_idx(1))*s_S + &
-                                                                      (1d0 - dir_flg(dir_idx(1)))* &
+                                                                      (1._wp - dir_flg(dir_idx(1)))* &
                                                                       vel_R(dir_idx(1))) - vel_R(dir_idx(1)))))
                                         ! Geometrical source of the void fraction(s) is zero
                                         !$acc loop seq
                                         do i = advxb, advxe
-                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                         end do
                                     end if
                                 #:endif
@@ -1568,18 +1572,18 @@ contains
                                     if (grid_geometry == 3) then
                                         !$acc loop seq
                                         do i = 1, sys_size
-                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                         end do
                                         flux_gsrc_rs${XYZ}$_vf(j, k, l, momxb + 1) = &
                                             -xi_M*(rho_L*(vel_L(dir_idx(1))* &
                                                           vel_L(dir_idx(1)) + &
                                                           s_M*(xi_L*(dir_flg(dir_idx(1))*s_S + &
-                                                                     (1d0 - dir_flg(dir_idx(1)))* &
+                                                                     (1._wp - dir_flg(dir_idx(1)))* &
                                                                      vel_L(dir_idx(1))) - vel_L(dir_idx(1))))) &
                                             - xi_P*(rho_R*(vel_R(dir_idx(1))* &
                                                            vel_R(dir_idx(1)) + &
                                                            s_P*(xi_R*(dir_flg(dir_idx(1))*s_S + &
-                                                                      (1d0 - dir_flg(dir_idx(1)))* &
+                                                                      (1._wp - dir_flg(dir_idx(1)))* &
                                                                       vel_R(dir_idx(1))) - vel_R(dir_idx(1)))))
                                         flux_gsrc_rs${XYZ}$_vf(j, k, l, momxe) = flux_rs${XYZ}$_vf(j, k, l, momxb + 1)
                                     end if
@@ -1601,23 +1605,23 @@ contains
                                     alpha_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)
                                 end do
 
-                                vel_L_rms = 0d0; vel_R_rms = 0d0
+                                vel_L_rms = 0._wp; vel_R_rms = 0._wp
 
                                 !$acc loop seq
                                 do i = 1, num_dims
                                     vel_L(i) = qL_prim_rs${XYZ}$_vf(j, k, l, contxe + i)
                                     vel_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, contxe + i)
-                                    vel_L_rms = vel_L_rms + vel_L(i)**2d0
-                                    vel_R_rms = vel_R_rms + vel_R(i)**2d0
+                                    vel_L_rms = vel_L_rms + vel_L(i)**2._wp
+                                    vel_R_rms = vel_R_rms + vel_R(i)**2._wp
                                 end do
 
                                 pres_L = qL_prim_rs${XYZ}$_vf(j, k, l, E_idx)
                                 pres_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx)
 
-                                rho_L = 0d0
-                                gamma_L = 0d0
-                                pi_inf_L = 0d0
-                                qv_L = 0d0
+                                rho_L = 0._wp
+                                gamma_L = 0._wp
+                                pi_inf_L = 0._wp
+                                qv_L = 0._wp
 
                                 ! Retain this in the refactor
                                 if (mpp_lim .and. (num_fluids > 2)) then
@@ -1643,10 +1647,10 @@ contains
                                     qv_L = qvs(1)
                                 end if
 
-                                rho_R = 0d0
-                                gamma_R = 0d0
-                                pi_inf_R = 0d0
-                                qv_R = 0d0
+                                rho_R = 0._wp
+                                gamma_R = 0._wp
+                                pi_inf_R = 0._wp
+                                qv_R = 0._wp
 
                                 if (mpp_lim .and. (num_fluids > 2)) then
                                     !$acc loop seq
@@ -1677,15 +1681,15 @@ contains
                                         do i = 1, 2
                                             Re_L(i) = dflt_real
 
-                                            if (Re_size(i) > 0) Re_L(i) = 0d0
+                                            if (Re_size(i) > 0) Re_L(i) = 0._wp
 
                                             !$acc loop seq
                                             do q = 1, Re_size(i)
-                                                Re_L(i) = (1d0 - qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + Re_idx(i, q)))/Res(i, q) &
+                                                Re_L(i) = (1._wp - qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + Re_idx(i, q)))/Res(i, q) &
                                                           + Re_L(i)
                                             end do
 
-                                            Re_L(i) = 1d0/max(Re_L(i), sgm_eps)
+                                            Re_L(i) = 1._wp/max(Re_L(i), sgm_eps)
 
                                         end do
 
@@ -1693,22 +1697,22 @@ contains
                                         do i = 1, 2
                                             Re_R(i) = dflt_real
 
-                                            if (Re_size(i) > 0) Re_R(i) = 0d0
+                                            if (Re_size(i) > 0) Re_R(i) = 0._wp
 
                                             !$acc loop seq
                                             do q = 1, Re_size(i)
-                                                Re_R(i) = (1d0 - qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + Re_idx(i, q)))/Res(i, q) &
+                                                Re_R(i) = (1._wp - qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + Re_idx(i, q)))/Res(i, q) &
                                                           + Re_R(i)
                                             end do
 
-                                            Re_R(i) = 1d0/max(Re_R(i), sgm_eps)
+                                            Re_R(i) = 1._wp/max(Re_R(i), sgm_eps)
                                         end do
                                     end if
                                 end if
 
-                                E_L = gamma_L*pres_L + pi_inf_L + 5d-1*rho_L*vel_L_rms
+                                E_L = gamma_L*pres_L + pi_inf_L + 5e-1_wp*rho_L*vel_L_rms
 
-                                E_R = gamma_R*pres_R + pi_inf_R + 5d-1*rho_R*vel_R_rms
+                                E_R = gamma_R*pres_R + pi_inf_R + 5e-1_wp*rho_R*vel_R_rms
 
                                 H_L = (E_L + pres_L)/rho_L
                                 H_R = (E_R + pres_R)/rho_R
@@ -1731,15 +1735,15 @@ contains
                                             nbub_L = qL_prim_rs${XYZ}$_vf(j, k, l, n_idx)
                                             nbub_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, n_idx)
                                         else
-                                            nbub_L_denom = 0d0
-                                            nbub_R_denom = 0d0
+                                            nbub_L_denom = 0._wp
+                                            nbub_R_denom = 0._wp
                                             !$acc loop seq
                                             do i = 1, nb
-                                                nbub_L_denom = nbub_L_denom + (R0_L(i)**3d0)*weight(i)
-                                                nbub_R_denom = nbub_R_denom + (R0_R(i)**3d0)*weight(i)
+                                                nbub_L_denom = nbub_L_denom + (R0_L(i)**3._wp)*weight(i)
+                                                nbub_R_denom = nbub_R_denom + (R0_R(i)**3._wp)*weight(i)
                                             end do
-                                            nbub_L = (3.d0/(4.d0*pi))*qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + num_fluids)/nbub_L_denom
-                                            nbub_R = (3.d0/(4.d0*pi))*qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + num_fluids)/nbub_R_denom
+                                            nbub_L = (3._wp/(4._wp*pi))*qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + num_fluids)/nbub_L_denom
+                                            nbub_R = (3._wp/(4._wp*pi))*qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + num_fluids)/nbub_R_denom
                                         end if
                                     else
                                         !nb stored in 0th moment of first R0 bin in variable conversion module
@@ -1751,8 +1755,8 @@ contains
                                     do i = 1, nb
                                         if (.not. qbmm) then
                                             if (polytropic) then
-                                                pbw_L(i) = f_cpbw_KM(R0(i), R0_L(i), V0_L(i), 0d0)
-                                                pbw_R(i) = f_cpbw_KM(R0(i), R0_R(i), V0_R(i), 0d0)
+                                                pbw_L(i) = f_cpbw_KM(R0(i), R0_L(i), V0_L(i), 0._wp)
+                                                pbw_R(i) = f_cpbw_KM(R0(i), R0_R(i), V0_R(i), 0._wp)
                                             else
                                                 pbw_L(i) = f_cpbw_KM(R0(i), R0_L(i), V0_L(i), P0_L(i))
                                                 pbw_R(i) = f_cpbw_KM(R0(i), R0_R(i), V0_R(i), P0_R(i))
@@ -1771,25 +1775,25 @@ contains
                                         R3V2Rbar = mom_sp_rs${XYZ}$_vf(j + 1, k, l, 3)
                                     else
 
-                                        PbwR3Lbar = 0d0
-                                        PbwR3Rbar = 0d0
+                                        PbwR3Lbar = 0._wp
+                                        PbwR3Rbar = 0._wp
 
-                                        R3Lbar = 0d0
-                                        R3Rbar = 0d0
+                                        R3Lbar = 0._wp
+                                        R3Rbar = 0._wp
 
-                                        R3V2Lbar = 0d0
-                                        R3V2Rbar = 0d0
+                                        R3V2Lbar = 0._wp
+                                        R3V2Rbar = 0._wp
 
                                         !$acc loop seq
                                         do i = 1, nb
-                                            PbwR3Lbar = PbwR3Lbar + pbw_L(i)*(R0_L(i)**3.d0)*weight(i)
-                                            PbwR3Rbar = PbwR3Rbar + pbw_R(i)*(R0_R(i)**3.d0)*weight(i)
+                                            PbwR3Lbar = PbwR3Lbar + pbw_L(i)*(R0_L(i)**3._wp)*weight(i)
+                                            PbwR3Rbar = PbwR3Rbar + pbw_R(i)*(R0_R(i)**3._wp)*weight(i)
 
-                                            R3Lbar = R3Lbar + (R0_L(i)**3.d0)*weight(i)
-                                            R3Rbar = R3Rbar + (R0_R(i)**3.d0)*weight(i)
+                                            R3Lbar = R3Lbar + (R0_L(i)**3._wp)*weight(i)
+                                            R3Rbar = R3Rbar + (R0_R(i)**3._wp)*weight(i)
 
-                                            R3V2Lbar = R3V2Lbar + (R0_L(i)**3.d0)*(V0_L(i)**2.d0)*weight(i)
-                                            R3V2Rbar = R3V2Rbar + (R0_R(i)**3.d0)*(V0_R(i)**2.d0)*weight(i)
+                                            R3V2Lbar = R3V2Lbar + (R0_L(i)**3._wp)*(V0_L(i)**2._wp)*weight(i)
+                                            R3V2Rbar = R3V2Rbar + (R0_R(i)**3._wp)*(V0_R(i)**2._wp)*weight(i)
                                         end do
                                     end if
 
@@ -1810,34 +1814,34 @@ contains
                                     if ((ptilde_L /= ptilde_L) .or. (ptilde_R /= ptilde_R)) then
                                     end if
 
-                                    rho_avg = 5d-1*(rho_L + rho_R)
-                                    H_avg = 5d-1*(H_L + H_R)
-                                    gamma_avg = 5d-1*(gamma_L + gamma_R)
-                                    vel_avg_rms = 0d0
+                                    rho_avg = 5e-1_wp*(rho_L + rho_R)
+                                    H_avg = 5e-1_wp*(H_L + H_R)
+                                    gamma_avg = 5e-1_wp*(gamma_L + gamma_R)
+                                    vel_avg_rms = 0._wp
 
                                     !$acc loop seq
                                     do i = 1, num_dims
-                                        vel_avg_rms = vel_avg_rms + (5d-1*(vel_L(i) + vel_R(i)))**2d0
+                                        vel_avg_rms = vel_avg_rms + (5e-1_wp*(vel_L(i) + vel_R(i)))**2._wp
                                     end do
 
                                 end if
 
                                 call s_compute_speed_of_sound(pres_L, rho_L, gamma_L, pi_inf_L, H_L, alpha_L, &
-                                                              vel_L_rms, 0d0, c_L)
+                                                              vel_L_rms, 0._wp, c_L)
 
                                 call s_compute_speed_of_sound(pres_R, rho_R, gamma_R, pi_inf_R, H_R, alpha_R, &
-                                                              vel_R_rms, 0d0, c_R)
+                                                              vel_R_rms, 0._wp, c_R)
 
                                 !> The computation of c_avg does not require all the variables, and therefore the non '_avg'
                                 ! variables are placeholders to call the subroutine.
 
                                 call s_compute_speed_of_sound(pres_R, rho_avg, gamma_avg, pi_inf_R, H_avg, alpha_R, &
-                                                              vel_avg_rms, 0d0, c_avg)
+                                                              vel_avg_rms, 0._wp, c_avg)
 
                                 if (viscous) then
                                     !$acc loop seq
                                     do i = 1, 2
-                                        Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2d0/(1d0/Re_L(i) + 1d0/Re_R(i))
+                                        Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2._wp/(1._wp/Re_L(i) + 1._wp/Re_R(i))
                                     end do
                                 end if
 
@@ -1856,30 +1860,30 @@ contains
                                           /(rho_L*(s_L - vel_L(dir_idx(1))) - &
                                             rho_R*(s_R - vel_R(dir_idx(1))))
                                 elseif (wave_speeds == 2) then
-                                    pres_SL = 5d-1*(pres_L + pres_R + rho_avg*c_avg* &
-                                                    (vel_L(dir_idx(1)) - &
-                                                     vel_R(dir_idx(1))))
+                                    pres_SL = 5e-1_wp*(pres_L + pres_R + rho_avg*c_avg* &
+                                                       (vel_L(dir_idx(1)) - &
+                                                        vel_R(dir_idx(1))))
 
                                     pres_SR = pres_SL
 
-                                    Ms_L = max(1d0, sqrt(1d0 + ((5d-1 + gamma_L)/(1d0 + gamma_L))* &
-                                                         (pres_SL/pres_L - 1d0)*pres_L/ &
-                                                         ((pres_L + pi_inf_L/(1d0 + gamma_L)))))
-                                    Ms_R = max(1d0, sqrt(1d0 + ((5d-1 + gamma_R)/(1d0 + gamma_R))* &
-                                                         (pres_SR/pres_R - 1d0)*pres_R/ &
-                                                         ((pres_R + pi_inf_R/(1d0 + gamma_R)))))
+                                    Ms_L = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_L)/(1._wp + gamma_L))* &
+                                                           (pres_SL/pres_L - 1._wp)*pres_L/ &
+                                                           ((pres_L + pi_inf_L/(1._wp + gamma_L)))))
+                                    Ms_R = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_R)/(1._wp + gamma_R))* &
+                                                           (pres_SR/pres_R - 1._wp)*pres_R/ &
+                                                           ((pres_R + pi_inf_R/(1._wp + gamma_R)))))
 
                                     s_L = vel_L(dir_idx(1)) - c_L*Ms_L
                                     s_R = vel_R(dir_idx(1)) + c_R*Ms_R
 
-                                    s_S = 5d-1*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
-                                                (pres_L - pres_R)/ &
-                                                (rho_avg*c_avg))
+                                    s_S = 5e-1_wp*((vel_L(dir_idx(1)) + vel_R(dir_idx(1))) + &
+                                                   (pres_L - pres_R)/ &
+                                                   (rho_avg*c_avg))
                                 end if
 
                                 ! follows Einfeldt et al.
                                 ! s_M/P = min/max(0.,s_L/R)
-                                s_M = min(0d0, s_L); s_P = max(0d0, s_R)
+                                s_M = min(0._wp, s_L); s_P = max(0._wp, s_R)
 
                                 ! goes with q_star_L/R = xi_L/R * (variable)
                                 ! xi_L/R = ( ( s_L/R - u_L/R )/(s_L/R - s_star) )
@@ -1888,27 +1892,27 @@ contains
 
                                 ! goes with numerical velocity in x/y/z directions
                                 ! xi_P/M = 0.5 +/m sgn(0.5,s_star)
-                                xi_M = (5d-1 + sign(5d-1, s_S))
-                                xi_P = (5d-1 - sign(5d-1, s_S))
+                                xi_M = (5e-1_wp + sign(5e-1_wp, s_S))
+                                xi_P = (5e-1_wp - sign(5e-1_wp, s_S))
 
                                 if (low_Mach == 1) then
                                     @:compute_low_Mach_correction()
                                 else
-                                    pcorr = 0d0
+                                    pcorr = 0._wp
                                 end if
 
                                 !$acc loop seq
                                 do i = 1, contxe
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 if (bubbles .and. (num_fluids > 1)) then
                                     ! Kill mass transport @ gas density
-                                    flux_rs${XYZ}$_vf(j, k, l, contxe) = 0.d0
+                                    flux_rs${XYZ}$_vf(j, k, l, contxe) = 0._wp
                                 end if
 
                                 ! Momentum flux.
@@ -1922,13 +1926,13 @@ contains
                                         xi_M*(rho_L*(vel_L(dir_idx(1))* &
                                                      vel_L(dir_idx(i)) + &
                                                      s_M*(xi_L*(dir_flg(dir_idx(i))*s_S + &
-                                                                (1d0 - dir_flg(dir_idx(i)))* &
+                                                                (1._wp - dir_flg(dir_idx(i)))* &
                                                                 vel_L(dir_idx(i))) - vel_L(dir_idx(i)))) + &
                                               dir_flg(dir_idx(i))*(pres_L - ptilde_L)) &
                                         + xi_P*(rho_R*(vel_R(dir_idx(1))* &
                                                        vel_R(dir_idx(i)) + &
                                                        s_P*(xi_R*(dir_flg(dir_idx(i))*s_S + &
-                                                                  (1d0 - dir_flg(dir_idx(i)))* &
+                                                                  (1._wp - dir_flg(dir_idx(i)))* &
                                                                   vel_R(dir_idx(i))) - vel_R(dir_idx(i)))) + &
                                                 dir_flg(dir_idx(i))*(pres_R - ptilde_R)) &
                                         + (s_M/s_L)*(s_P/s_R)*dir_flg(dir_idx(i))*pcorr
@@ -1954,9 +1958,9 @@ contains
                                 do i = advxb, advxe
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 ! Source for volume fraction advection equation
@@ -1965,12 +1969,12 @@ contains
                                     vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(i)) = &
                                         xi_M*(vel_L(dir_idx(i)) + &
                                               dir_flg(dir_idx(i))* &
-                                              s_M*(xi_L - 1d0)) &
+                                              s_M*(xi_L - 1._wp)) &
                                         + xi_P*(vel_R(dir_idx(i)) + &
                                                 dir_flg(dir_idx(i))* &
-                                                s_P*(xi_R - 1d0))
+                                                s_P*(xi_R - 1._wp))
 
-                                    !IF ( (model_eqns == 4) .or. (num_fluids==1) ) vel_src_rs_vf(idxi)%sf(j,k,l) = 0d0
+                                    !IF ( (model_eqns == 4) .or. (num_fluids==1) ) vel_src_rs_vf(idxi)%sf(j,k,l) = 0._wp
                                 end do
 
                                 flux_src_rs${XYZ}$_vf(j, k, l, advxb) = vel_src_rs${XYZ}$_vf(j, k, l, dir_idx(1))
@@ -1980,25 +1984,25 @@ contains
                                 do i = bubxb, bubxe
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*nbub_L*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*nbub_R*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 if (qbmm) then
                                     flux_rs${XYZ}$_vf(j, k, l, bubxb) = &
                                         xi_M*nbub_L &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*nbub_R &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end if
 
                                 if (adv_n) then
                                     flux_rs${XYZ}$_vf(j, k, l, n_idx) = &
                                         xi_M*nbub_L &
-                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(dir_idx(1)) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*nbub_R &
-                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1d0))
+                                        *(vel_R(dir_idx(1)) + s_P*(xi_R - 1._wp))
                                 end if
 
                                 ! Geometrical source flux for cylindrical coordinates
@@ -2014,17 +2018,17 @@ contains
                                             xi_M*(rho_L*(vel_L(dir_idx(1))* &
                                                          vel_L(dir_idx(1)) + &
                                                          s_M*(xi_L*(dir_flg(dir_idx(1))*s_S + &
-                                                                    (1d0 - dir_flg(dir_idx(1)))* &
+                                                                    (1._wp - dir_flg(dir_idx(1)))* &
                                                                     vel_L(dir_idx(1))) - vel_L(dir_idx(1))))) &
                                             + xi_P*(rho_R*(vel_R(dir_idx(1))* &
                                                            vel_R(dir_idx(1)) + &
                                                            s_P*(xi_R*(dir_flg(dir_idx(1))*s_S + &
-                                                                      (1d0 - dir_flg(dir_idx(1)))* &
+                                                                      (1._wp - dir_flg(dir_idx(1)))* &
                                                                       vel_R(dir_idx(1))) - vel_R(dir_idx(1)))))
                                         ! Geometrical source of the void fraction(s) is zero
                                         !$acc loop seq
                                         do i = advxb, advxe
-                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                         end do
                                     end if
                                 #:endif
@@ -2032,19 +2036,19 @@ contains
                                     if (grid_geometry == 3) then
                                         !$acc loop seq
                                         do i = 1, sys_size
-                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                         end do
 
                                         flux_gsrc_rs${XYZ}$_vf(j, k, l, momxb + 1) = &
                                             -xi_M*(rho_L*(vel_L(dir_idx(1))* &
                                                           vel_L(dir_idx(1)) + &
                                                           s_M*(xi_L*(dir_flg(dir_idx(1))*s_S + &
-                                                                     (1d0 - dir_flg(dir_idx(1)))* &
+                                                                     (1._wp - dir_flg(dir_idx(1)))* &
                                                                      vel_L(dir_idx(1))) - vel_L(dir_idx(1))))) &
                                             - xi_P*(rho_R*(vel_R(dir_idx(1))* &
                                                            vel_R(dir_idx(1)) + &
                                                            s_P*(xi_R*(dir_flg(dir_idx(1))*s_S + &
-                                                                      (1d0 - dir_flg(dir_idx(1)))* &
+                                                                      (1._wp - dir_flg(dir_idx(1)))* &
                                                                       vel_R(dir_idx(1))) - vel_R(dir_idx(1)))))
                                         flux_gsrc_rs${XYZ}$_vf(j, k, l, momxe) = flux_rs${XYZ}$_vf(j, k, l, momxb + 1)
 
@@ -2071,38 +2075,38 @@ contains
                                     alpha_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)
                                 end do
 
-                                vel_L_rms = 0d0; vel_R_rms = 0d0
+                                vel_L_rms = 0._wp; vel_R_rms = 0._wp
                                 !$acc loop seq
                                 do i = 1, num_dims
                                     vel_L(i) = qL_prim_rs${XYZ}$_vf(j, k, l, contxe + i)
                                     vel_R(i) = qR_prim_rs${XYZ}$_vf(j + 1, k, l, contxe + i)
-                                    vel_L_rms = vel_L_rms + vel_L(i)**2d0
-                                    vel_R_rms = vel_R_rms + vel_R(i)**2d0
+                                    vel_L_rms = vel_L_rms + vel_L(i)**2._wp
+                                    vel_R_rms = vel_R_rms + vel_R(i)**2._wp
                                 end do
 
                                 pres_L = qL_prim_rs${XYZ}$_vf(j, k, l, E_idx)
                                 pres_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx)
 
-                                rho_L = 0d0
-                                gamma_L = 0d0
-                                pi_inf_L = 0d0
-                                qv_L = 0d0
+                                rho_L = 0._wp
+                                gamma_L = 0._wp
+                                pi_inf_L = 0._wp
+                                qv_L = 0._wp
 
-                                rho_R = 0d0
-                                gamma_R = 0d0
-                                pi_inf_R = 0d0
-                                qv_R = 0d0
+                                rho_R = 0._wp
+                                gamma_R = 0._wp
+                                pi_inf_R = 0._wp
+                                qv_R = 0._wp
 
-                                alpha_L_sum = 0d0
-                                alpha_R_sum = 0d0
+                                alpha_L_sum = 0._wp
+                                alpha_R_sum = 0._wp
 
                                 ! Change this by splitting it into the cases
                                 ! present in the bubbles
                                 if (mpp_lim) then
                                     !$acc loop seq
                                     do i = 1, num_fluids
-                                        qL_prim_rs${XYZ}$_vf(j, k, l, i) = max(0d0, qL_prim_rs${XYZ}$_vf(j, k, l, i))
-                                        qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i) = min(max(0d0, qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i)), 1d0)
+                                        qL_prim_rs${XYZ}$_vf(j, k, l, i) = max(0._wp, qL_prim_rs${XYZ}$_vf(j, k, l, i))
+                                        qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i) = min(max(0._wp, qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i)), 1._wp)
                                         alpha_L_sum = alpha_L_sum + qL_prim_rs${XYZ}$_vf(j, k, l, E_idx + i)
                                     end do
 
@@ -2113,8 +2117,8 @@ contains
 
                                     !$acc loop seq
                                     do i = 1, num_fluids
-                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) = max(0d0, qR_prim_rs${XYZ}$_vf(j + 1, k, l, i))
-                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i) = min(max(0d0, qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)), 1d0)
+                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) = max(0._wp, qR_prim_rs${XYZ}$_vf(j + 1, k, l, i))
+                                        qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i) = min(max(0._wp, qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)), 1._wp)
                                         alpha_R_sum = alpha_R_sum + qR_prim_rs${XYZ}$_vf(j + 1, k, l, E_idx + i)
                                     end do
 
@@ -2142,7 +2146,7 @@ contains
                                     do i = 1, 2
                                         Re_L(i) = dflt_real
 
-                                        if (Re_size(i) > 0) Re_L(i) = 0d0
+                                        if (Re_size(i) > 0) Re_L(i) = 0._wp
 
                                         !$acc loop seq
                                         do q = 1, Re_size(i)
@@ -2150,7 +2154,7 @@ contains
                                                       + Re_L(i)
                                         end do
 
-                                        Re_L(i) = 1d0/max(Re_L(i), sgm_eps)
+                                        Re_L(i) = 1._wp/max(Re_L(i), sgm_eps)
 
                                     end do
 
@@ -2158,7 +2162,7 @@ contains
                                     do i = 1, 2
                                         Re_R(i) = dflt_real
 
-                                        if (Re_size(i) > 0) Re_R(i) = 0d0
+                                        if (Re_size(i) > 0) Re_R(i) = 0._wp
 
                                         !$acc loop seq
                                         do q = 1, Re_size(i)
@@ -2166,12 +2170,12 @@ contains
                                                       + Re_R(i)
                                         end do
 
-                                        Re_R(i) = 1d0/max(Re_R(i), sgm_eps)
+                                        Re_R(i) = 1._wp/max(Re_R(i), sgm_eps)
                                     end do
                                 end if
 
                                 if (chemistry) then
-                                    c_sum_Yi_Phi = 0.0d0
+                                    c_sum_Yi_Phi = 0.0_wp
                                     !$acc loop seq
                                     do i = chemxb, chemxe
                                         Ys_L(i - chemxb + 1) = qL_prim_rs${XYZ}$_vf(j, k, l, i)
@@ -2195,11 +2199,11 @@ contains
 
                                     if (chem_params%gamma_method == 1) then
                                         !> gamma_method = 1: Ref. Section 2.3.1 Formulation of doi:10.7907/ZKW8-ES97.
-                                        Gamma_iL = Cp_iL/(Cp_iL - 1.0d0)
-                                        Gamma_iR = Cp_iR/(Cp_iR - 1.0d0)
+                                        Gamma_iL = Cp_iL/(Cp_iL - 1.0_wp)
+                                        Gamma_iR = Cp_iR/(Cp_iR - 1.0_wp)
 
-                                        gamma_L = sum(Xs_L(:)/(Gamma_iL(:) - 1.0d0))
-                                        gamma_R = sum(Xs_R(:)/(Gamma_iR(:) - 1.0d0))
+                                        gamma_L = sum(Xs_L(:)/(Gamma_iL(:) - 1.0_wp))
+                                        gamma_R = sum(Xs_R(:)/(Gamma_iR(:) - 1.0_wp))
                                     else if (chem_params%gamma_method == 2) then
                                         !> gamma_method = 2: c_p / c_v where c_p, c_v are specific heats.
                                         call get_mixture_specific_heat_cp_mass(T_L, Ys_L, Cp_L)
@@ -2208,22 +2212,22 @@ contains
                                         call get_mixture_specific_heat_cv_mass(T_R, Ys_R, Cv_R)
 
                                         Gamm_L = Cp_L/Cv_L
-                                        gamma_L = 1.0d0/(Gamm_L - 1.0d0)
+                                        gamma_L = 1.0_wp/(Gamm_L - 1.0_wp)
                                         Gamm_R = Cp_R/Cv_R
-                                        gamma_R = 1.0d0/(Gamm_R - 1.0d0)
+                                        gamma_R = 1.0_wp/(Gamm_R - 1.0_wp)
                                     end if
 
                                     call get_mixture_energy_mass(T_L, Ys_L, E_L)
                                     call get_mixture_energy_mass(T_R, Ys_R, E_R)
 
-                                    E_L = rho_L*E_L + 5d-1*rho_L*vel_L_rms
-                                    E_R = rho_R*E_R + 5d-1*rho_R*vel_R_rms
+                                    E_L = rho_L*E_L + 5e-1*rho_L*vel_L_rms
+                                    E_R = rho_R*E_R + 5e-1*rho_R*vel_R_rms
                                     H_L = (E_L + pres_L)/rho_L
                                     H_R = (E_R + pres_R)/rho_R
                                 else
-                                    E_L = gamma_L*pres_L + pi_inf_L + 5d-1*rho_L*vel_L_rms + qv_L
+                                    E_L = gamma_L*pres_L + pi_inf_L + 5e-1*rho_L*vel_L_rms + qv_L
 
-                                    E_R = gamma_R*pres_R + pi_inf_R + 5d-1*rho_R*vel_R_rms + qv_R
+                                    E_R = gamma_R*pres_R + pi_inf_R + 5e-1*rho_R*vel_R_rms + qv_R
 
                                     H_L = (E_L + pres_L)/rho_L
                                     H_R = (E_R + pres_R)/rho_R
@@ -2232,10 +2236,10 @@ contains
                                 @:compute_average_state()
 
                                 call s_compute_speed_of_sound(pres_L, rho_L, gamma_L, pi_inf_L, H_L, alpha_L, &
-                                                              vel_L_rms, 0d0, c_L)
+                                                              vel_L_rms, 0._wp, c_L)
 
                                 call s_compute_speed_of_sound(pres_R, rho_R, gamma_R, pi_inf_R, H_R, alpha_R, &
-                                                              vel_R_rms, 0d0, c_R)
+                                                              vel_R_rms, 0._wp, c_R)
 
                                 !> The computation of c_avg does not require all the variables, and therefore the non '_avg'
                                 ! variables are placeholders to call the subroutine.
@@ -2246,7 +2250,7 @@ contains
                                 if (viscous) then
                                     !$acc loop seq
                                     do i = 1, 2
-                                        Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2d0/(1d0/Re_L(i) + 1d0/Re_R(i))
+                                        Re_avg_rs${XYZ}$_vf(j, k, l, i) = 2._wp/(1._wp/Re_L(i) + 1._wp/Re_R(i))
                                     end do
                                 end if
 
@@ -2266,30 +2270,30 @@ contains
                                             rho_R*(s_R - vel_R(idx1)))
 
                                 elseif (wave_speeds == 2) then
-                                    pres_SL = 5d-1*(pres_L + pres_R + rho_avg*c_avg* &
-                                                    (vel_L(idx1) - &
-                                                     vel_R(idx1)))
+                                    pres_SL = 5e-1_wp*(pres_L + pres_R + rho_avg*c_avg* &
+                                                       (vel_L(idx1) - &
+                                                        vel_R(idx1)))
 
                                     pres_SR = pres_SL
 
-                                    Ms_L = max(1d0, sqrt(1d0 + ((5d-1 + gamma_L)/(1d0 + gamma_L))* &
-                                                         (pres_SL/pres_L - 1d0)*pres_L/ &
-                                                         ((pres_L + pi_inf_L/(1d0 + gamma_L)))))
-                                    Ms_R = max(1d0, sqrt(1d0 + ((5d-1 + gamma_R)/(1d0 + gamma_R))* &
-                                                         (pres_SR/pres_R - 1d0)*pres_R/ &
-                                                         ((pres_R + pi_inf_R/(1d0 + gamma_R)))))
+                                    Ms_L = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_L)/(1._wp + gamma_L))* &
+                                                           (pres_SL/pres_L - 1._wp)*pres_L/ &
+                                                           ((pres_L + pi_inf_L/(1._wp + gamma_L)))))
+                                    Ms_R = max(1._wp, sqrt(1._wp + ((5e-1_wp + gamma_R)/(1._wp + gamma_R))* &
+                                                           (pres_SR/pres_R - 1._wp)*pres_R/ &
+                                                           ((pres_R + pi_inf_R/(1._wp + gamma_R)))))
 
                                     s_L = vel_L(idx1) - c_L*Ms_L
                                     s_R = vel_R(idx1) + c_R*Ms_R
 
-                                    s_S = 5d-1*((vel_L(idx1) + vel_R(idx1)) + &
-                                                (pres_L - pres_R)/ &
-                                                (rho_avg*c_avg))
+                                    s_S = 5e-1_wp*((vel_L(idx1) + vel_R(idx1)) + &
+                                                   (pres_L - pres_R)/ &
+                                                   (rho_avg*c_avg))
                                 end if
 
                                 ! follows Einfeldt et al.
                                 ! s_M/P = min/max(0.,s_L/R)
-                                s_M = min(0d0, s_L); s_P = max(0d0, s_R)
+                                s_M = min(0._wp, s_L); s_P = max(0._wp, s_R)
 
                                 ! goes with q_star_L/R = xi_L/R * (variable)
                                 ! xi_L/R = ( ( s_L/R - u_L/R )/(s_L/R - s_star) )
@@ -2298,22 +2302,22 @@ contains
 
                                 ! goes with numerical velocity in x/y/z directions
                                 ! xi_P/M = 0.5 +/m sgn(0.5,s_star)
-                                xi_M = (5d-1 + sign(5d-1, s_S))
-                                xi_P = (5d-1 - sign(5d-1, s_S))
+                                xi_M = (5e-1_wp + sign(5e-1_wp, s_S))
+                                xi_P = (5e-1_wp - sign(5e-1_wp, s_S))
 
                                 if (low_Mach == 1) then
                                     @:compute_low_Mach_correction()
                                 else
-                                    pcorr = 0d0
+                                    pcorr = 0._wp
                                 end if
 
                                 !$acc loop seq
                                 do i = 1, contxe
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                        *(vel_L(idx1) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(idx1) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                        *(vel_R(idx1) + s_P*(xi_R - 1d0))
+                                        *(vel_R(idx1) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 ! Momentum flux.
@@ -2325,13 +2329,13 @@ contains
                                         xi_M*(rho_L*(vel_L(idx1)* &
                                                      vel_L(idxi) + &
                                                      s_M*(xi_L*(dir_flg(idxi)*s_S + &
-                                                                (1d0 - dir_flg(idxi))* &
+                                                                (1._wp - dir_flg(idxi))* &
                                                                 vel_L(idxi)) - vel_L(idxi))) + &
                                               dir_flg(idxi)*(pres_L)) &
                                         + xi_P*(rho_R*(vel_R(idx1)* &
                                                        vel_R(idxi) + &
                                                        s_P*(xi_R*(dir_flg(idxi)*s_S + &
-                                                                  (1d0 - dir_flg(idxi))* &
+                                                                  (1._wp - dir_flg(idxi))* &
                                                                   vel_R(idxi)) - vel_R(idxi))) + &
                                                 dir_flg(idxi)*(pres_R)) &
                                         + (s_M/s_L)*(s_P/s_R)*dir_flg(idxi)*pcorr
@@ -2355,9 +2359,9 @@ contains
                                 do i = advxb, advxe
                                     flux_rs${XYZ}$_vf(j, k, l, i) = &
                                         xi_M*qL_prim_rs${XYZ}$_vf(j, k, l, i) &
-                                        *(vel_L(idx1) + s_M*(xi_L - 1d0)) &
+                                        *(vel_L(idx1) + s_M*(xi_L - 1._wp)) &
                                         + xi_P*qR_prim_rs${XYZ}$_vf(j + 1, k, l, i) &
-                                        *(vel_R(idx1) + s_P*(xi_R - 1d0))
+                                        *(vel_R(idx1) + s_P*(xi_R - 1._wp))
                                 end do
 
                                 ! Source for volume fraction advection equation
@@ -2367,12 +2371,12 @@ contains
                                     vel_src_rs${XYZ}$_vf(j, k, l, idxi) = &
                                         xi_M*(vel_L(idxi) + &
                                               dir_flg(idxi)* &
-                                              s_M*(xi_L - 1d0)) &
+                                              s_M*(xi_L - 1._wp)) &
                                         + xi_P*(vel_R(idxi) + &
                                                 dir_flg(idxi)* &
-                                                s_P*(xi_R - 1d0))
+                                                s_P*(xi_R - 1._wp))
 
-                                    !if ( (model_eqns == 4) .or. (num_fluids==1) ) vel_src_rs_vf(dir_idx(i))%sf(j,k,l) = 0d0
+                                    !if ( (model_eqns == 4) .or. (num_fluids==1) ) vel_src_rs_vf(dir_idx(i))%sf(j,k,l) = 0._wp
                                 end do
 
                                 flux_src_rs${XYZ}$_vf(j, k, l, advxb) = vel_src_rs${XYZ}$_vf(j, k, l, idx1)
@@ -2383,9 +2387,9 @@ contains
                                         Y_L = qL_prim_rs${XYZ}$_vf(j, k, l, i)
                                         Y_R = qR_prim_rs${XYZ}$_vf(j + 1, k, l, i)
 
-                                        flux_rs${XYZ}$_vf(j, k, l, i) = xi_M*rho_L*Y_L*(vel_L(idx1) + s_M*(xi_L - 1d0)) &
-                                                                        + xi_P*rho_R*Y_R*(vel_R(idx1) + s_P*(xi_R - 1d0))
-                                        flux_src_rs${XYZ}$_vf(j, k, l, i) = 0.0d0
+                                        flux_rs${XYZ}$_vf(j, k, l, i) = xi_M*rho_L*Y_L*(vel_L(idx1) + s_M*(xi_L - 1._wp)) &
+                                                                        + xi_P*rho_R*Y_R*(vel_R(idx1) + s_P*(xi_R - 1._wp))
+                                        flux_src_rs${XYZ}$_vf(j, k, l, i) = 0.0_wp
                                     end do
                                 end if
 
@@ -2403,17 +2407,17 @@ contains
                                             xi_M*(rho_L*(vel_L(idx1)* &
                                                          vel_L(idx1) + &
                                                          s_M*(xi_L*(dir_flg(idx1)*s_S + &
-                                                                    (1d0 - dir_flg(idx1))* &
+                                                                    (1._wp - dir_flg(idx1))* &
                                                                     vel_L(idx1)) - vel_L(idx1)))) &
                                             + xi_P*(rho_R*(vel_R(idx1)* &
                                                            vel_R(idx1) + &
                                                            s_P*(xi_R*(dir_flg(idx1)*s_S + &
-                                                                      (1d0 - dir_flg(idx1))* &
+                                                                      (1._wp - dir_flg(idx1))* &
                                                                       vel_R(idx1)) - vel_R(idx1))))
                                         ! Geometrical source of the void fraction(s) is zero
                                         !$acc loop seq
                                         do i = advxb, advxe
-                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                         end do
                                     end if
                                 #:endif
@@ -2421,19 +2425,19 @@ contains
                                     if (grid_geometry == 3) then
                                         !$acc loop seq
                                         do i = 1, sys_size
-                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0d0
+                                            flux_gsrc_rs${XYZ}$_vf(j, k, l, i) = 0._wp
                                         end do
 
                                         flux_gsrc_rs${XYZ}$_vf(j, k, l, momxb + 1) = &
                                             -xi_M*(rho_L*(vel_L(idx1)* &
                                                           vel_L(idx1) + &
                                                           s_M*(xi_L*(dir_flg(idx1)*s_S + &
-                                                                     (1d0 - dir_flg(idx1))* &
+                                                                     (1._wp - dir_flg(idx1))* &
                                                                      vel_L(idx1)) - vel_L(idx1)))) &
                                             - xi_P*(rho_R*(vel_R(idx1)* &
                                                            vel_R(idx1) + &
                                                            s_P*(xi_R*(dir_flg(idx1)*s_S + &
-                                                                      (1d0 - dir_flg(idx1))* &
+                                                                      (1._wp - dir_flg(idx1))* &
                                                                       vel_R(idx1)) - vel_R(idx1))))
                                         flux_gsrc_rs${XYZ}$_vf(j, k, l, momxe) = flux_rs${XYZ}$_vf(j, k, l, momxb + 1)
 
@@ -2642,7 +2646,7 @@ contains
         qR_prim_vf, &
         norm_dir, ix, iy, iz)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: qL_prim_rsx_vf, qL_prim_rsy_vf, qL_prim_rsz_vf, qR_prim_rsx_vf, qR_prim_rsy_vf, qR_prim_rsz_vf
 
         type(scalar_field), &
             allocatable, dimension(:), &
@@ -2658,13 +2662,13 @@ contains
 
         if (norm_dir == 1) then
             is1 = ix; is2 = iy; is3 = iz
-            dir_idx = (/1, 2, 3/); dir_flg = (/1d0, 0d0, 0d0/)
+            dir_idx = (/1, 2, 3/); dir_flg = (/1._wp, 0._wp, 0._wp/)
         elseif (norm_dir == 2) then
             is1 = iy; is2 = ix; is3 = iz
-            dir_idx = (/2, 1, 3/); dir_flg = (/0d0, 1d0, 0d0/)
+            dir_idx = (/2, 1, 3/); dir_flg = (/0._wp, 1._wp, 0._wp/)
         else
             is1 = iz; is2 = iy; is3 = ix
-            dir_idx = (/3, 1, 2/); dir_flg = (/0d0, 0d0, 1d0/)
+            dir_idx = (/3, 1, 2/); dir_flg = (/0._wp, 0._wp, 1._wp/)
         end if
 
         !$acc update device(is1, is2, is3)
@@ -3040,7 +3044,7 @@ contains
                     do l = is3%beg, is3%end
                         do k = is2%beg, is2%end
                             do j = is1%beg, is1%end
-                                flux_src_vf(i)%sf(j, k, l) = 0d0
+                                flux_src_vf(i)%sf(j, k, l) = 0._wp
                             end do
                         end do
                     end do
@@ -3072,7 +3076,7 @@ contains
                     do l = is3%beg, is3%end
                         do j = is1%beg, is1%end
                             do k = is2%beg, is2%end
-                                flux_src_vf(i)%sf(k, j, l) = 0d0
+                                flux_src_vf(i)%sf(k, j, l) = 0._wp
                             end do
                         end do
                     end do
@@ -3103,7 +3107,7 @@ contains
                     do j = is1%beg, is1%end
                         do k = is2%beg, is2%end
                             do l = is3%beg, is3%end
-                                flux_src_vf(i)%sf(l, k, j) = 0d0
+                                flux_src_vf(i)%sf(l, k, j) = 0._wp
                             end do
                         end do
                     end do
@@ -3175,13 +3179,13 @@ contains
         ! Arithmetic mean of the left and right, WENO-reconstructed, cell-
         ! boundary values of cell-average first-order spatial derivatives
         ! of velocity
-        real(kind(0d0)), dimension(num_dims) :: avg_vel
-        real(kind(0d0)), dimension(num_dims) :: dvel_avg_dx
-        real(kind(0d0)), dimension(num_dims) :: dvel_avg_dy
-        real(kind(0d0)), dimension(num_dims) :: dvel_avg_dz
+        real(wp), dimension(num_dims) :: avg_vel
+        real(wp), dimension(num_dims) :: dvel_avg_dx
+        real(wp), dimension(num_dims) :: dvel_avg_dy
+        real(wp), dimension(num_dims) :: dvel_avg_dz
 
         ! Viscous stress tensor
-        real(kind(0d0)), dimension(num_dims, num_dims) :: tau_Re
+        real(wp), dimension(num_dims, num_dims) :: tau_Re
 
         ! Generic loop iterators
         integer :: i, j, k, l
@@ -3194,10 +3198,10 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j + 1, k, l))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j + 1, k, l))
 
-                            tau_Re(1, 1) = (4d0/3d0)*dvel_avg_dx(1)/ &
+                            tau_Re(1, 1) = (4._wp/3._wp)*dvel_avg_dx(1)/ &
                                            Re_avg_rsx_vf(j, k, l, 1)
 
                             flux_src_vf(momxb)%sf(j, k, l) = &
@@ -3220,8 +3224,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j + 1, k, l))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j + 1, k, l))
 
                             tau_Re(1, 1) = dvel_avg_dx(1)/ &
                                            Re_avg_rsx_vf(j, k, l, 2)
@@ -3248,21 +3252,21 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            avg_vel(2) = 5d-1*(velL_vf(2)%sf(j, k, l) &
-                                               + velR_vf(2)%sf(j + 1, k, l))
+                            avg_vel(2) = 5e-1_wp*(velL_vf(2)%sf(j, k, l) &
+                                                  + velR_vf(2)%sf(j + 1, k, l))
 
                             !$acc loop seq
                             do i = 1, 2
                                 dvel_avg_dy(i) = &
-                                    5d-1*(dvelL_dy_vf(i)%sf(j, k, l) &
-                                          + dvelR_dy_vf(i)%sf(j + 1, k, l))
+                                    5e-1_wp*(dvelL_dy_vf(i)%sf(j, k, l) &
+                                             + dvelR_dy_vf(i)%sf(j + 1, k, l))
                             end do
 
-                            dvel_avg_dx(2) = 5d-1*(dvelL_dx_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(2)%sf(j + 1, k, l))
+                            dvel_avg_dx(2) = 5e-1_wp*(dvelL_dx_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(2)%sf(j + 1, k, l))
 
-                            tau_Re(1, 1) = -(2d0/3d0)*(dvel_avg_dy(2) + &
-                                                       avg_vel(2)/y_cc(k))/ &
+                            tau_Re(1, 1) = -(2._wp/3._wp)*(dvel_avg_dy(2) + &
+                                                           avg_vel(2)/y_cc(k))/ &
                                            Re_avg_rsx_vf(j, k, l, 1)
 
                             tau_Re(1, 2) = (dvel_avg_dy(1) + dvel_avg_dx(2))/ &
@@ -3290,11 +3294,11 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            avg_vel(2) = 5d-1*(velL_vf(2)%sf(j, k, l) &
-                                               + velR_vf(2)%sf(j + 1, k, l))
+                            avg_vel(2) = 5e-1_wp*(velL_vf(2)%sf(j, k, l) &
+                                                  + velR_vf(2)%sf(j + 1, k, l))
 
-                            dvel_avg_dy(2) = 5d-1*(dvelL_dy_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(2)%sf(j + 1, k, l))
+                            dvel_avg_dy(2) = 5e-1_wp*(dvelL_dy_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(2)%sf(j + 1, k, l))
 
                             tau_Re(1, 1) = (dvel_avg_dy(2) + &
                                             avg_vel(2)/y_cc(k))/ &
@@ -3325,14 +3329,14 @@ contains
                             !$acc loop seq
                             do i = 1, 3, 2
                                 dvel_avg_dz(i) = &
-                                    5d-1*(dvelL_dz_vf(i)%sf(j, k, l) &
-                                          + dvelR_dz_vf(i)%sf(j + 1, k, l))
+                                    5e-1_wp*(dvelL_dz_vf(i)%sf(j, k, l) &
+                                             + dvelR_dz_vf(i)%sf(j + 1, k, l))
                             end do
 
-                            dvel_avg_dx(3) = 5d-1*(dvelL_dx_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(3)%sf(j + 1, k, l))
+                            dvel_avg_dx(3) = 5e-1_wp*(dvelL_dx_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(3)%sf(j + 1, k, l))
 
-                            tau_Re(1, 1) = -(2d0/3d0)*dvel_avg_dz(3)/y_cc(k)/ &
+                            tau_Re(1, 1) = -(2._wp/3._wp)*dvel_avg_dz(3)/y_cc(k)/ &
                                            Re_avg_rsx_vf(j, k, l, 1)
 
                             tau_Re(1, 3) = (dvel_avg_dz(1)/y_cc(k) + dvel_avg_dx(3))/ &
@@ -3363,8 +3367,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dz(3) = 5d-1*(dvelL_dz_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dz_vf(3)%sf(j + 1, k, l))
+                            dvel_avg_dz(3) = 5e-1_wp*(dvelL_dz_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dz_vf(3)%sf(j + 1, k, l))
 
                             tau_Re(1, 1) = dvel_avg_dz(3)/y_cc(k)/ &
                                            Re_avg_rsx_vf(j, k, l, 2)
@@ -3394,29 +3398,29 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            avg_vel(2) = 5d-1*(velL_vf(2)%sf(j, k, l) &
-                                               + velR_vf(2)%sf(j, k + 1, l))
+                            avg_vel(2) = 5e-1_wp*(velL_vf(2)%sf(j, k, l) &
+                                                  + velR_vf(2)%sf(j, k + 1, l))
 
                             !$acc loop seq
                             do i = 1, 2
 
                                 dvel_avg_dx(i) = &
-                                    5d-1*(dvelL_dx_vf(i)%sf(j, k, l) &
-                                          + dvelR_dx_vf(i)%sf(j, k + 1, l))
+                                    5e-1_wp*(dvelL_dx_vf(i)%sf(j, k, l) &
+                                             + dvelR_dx_vf(i)%sf(j, k + 1, l))
 
                                 dvel_avg_dy(i) = &
-                                    5d-1*(dvelL_dy_vf(i)%sf(j, k, l) &
-                                          + dvelR_dy_vf(i)%sf(j, k + 1, l))
+                                    5e-1_wp*(dvelL_dy_vf(i)%sf(j, k, l) &
+                                             + dvelR_dy_vf(i)%sf(j, k + 1, l))
 
                             end do
 
                             tau_Re(2, 1) = (dvel_avg_dy(1) + dvel_avg_dx(2))/ &
                                            Re_avg_rsy_vf(k, j, l, 1)
 
-                            tau_Re(2, 2) = (4d0*dvel_avg_dy(2) &
-                                            - 2d0*dvel_avg_dx(1) &
-                                            - 2d0*avg_vel(2)/y_cb(k))/ &
-                                           (3d0*Re_avg_rsy_vf(k, j, l, 1))
+                            tau_Re(2, 2) = (4._wp*dvel_avg_dy(2) &
+                                            - 2._wp*dvel_avg_dx(1) &
+                                            - 2._wp*avg_vel(2)/y_cb(k))/ &
+                                           (3._wp*Re_avg_rsy_vf(k, j, l, 1))
 
                             !$acc loop seq
                             do i = 1, 2
@@ -3443,14 +3447,14 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            avg_vel(2) = 5d-1*(velL_vf(2)%sf(j, k, l) &
-                                               + velR_vf(2)%sf(j, k + 1, l))
+                            avg_vel(2) = 5e-1_wp*(velL_vf(2)%sf(j, k, l) &
+                                                  + velR_vf(2)%sf(j, k + 1, l))
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j, k + 1, l))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j, k + 1, l))
 
-                            dvel_avg_dy(2) = 5d-1*(dvelL_dy_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(2)%sf(j, k + 1, l))
+                            dvel_avg_dy(2) = 5e-1_wp*(dvelL_dy_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(2)%sf(j, k + 1, l))
 
                             tau_Re(2, 2) = (dvel_avg_dx(1) + dvel_avg_dy(2) + &
                                             avg_vel(2)/y_cb(k))/ &
@@ -3478,20 +3482,20 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            avg_vel(3) = 5d-1*(velL_vf(3)%sf(j, k, l) &
-                                               + velR_vf(3)%sf(j, k + 1, l))
+                            avg_vel(3) = 5e-1_wp*(velL_vf(3)%sf(j, k, l) &
+                                                  + velR_vf(3)%sf(j, k + 1, l))
 
                             !$acc loop seq
                             do i = 2, 3
                                 dvel_avg_dz(i) = &
-                                    5d-1*(dvelL_dz_vf(i)%sf(j, k, l) &
-                                          + dvelR_dz_vf(i)%sf(j, k + 1, l))
+                                    5e-1_wp*(dvelL_dz_vf(i)%sf(j, k, l) &
+                                             + dvelR_dz_vf(i)%sf(j, k + 1, l))
                             end do
 
-                            dvel_avg_dy(3) = 5d-1*(dvelL_dy_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(3)%sf(j, k + 1, l))
+                            dvel_avg_dy(3) = 5e-1_wp*(dvelL_dy_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(3)%sf(j, k + 1, l))
 
-                            tau_Re(2, 2) = -(2d0/3d0)*dvel_avg_dz(3)/y_cb(k)/ &
+                            tau_Re(2, 2) = -(2._wp/3._wp)*dvel_avg_dz(3)/y_cb(k)/ &
                                            Re_avg_rsy_vf(k, j, l, 1)
 
                             tau_Re(2, 3) = ((dvel_avg_dz(2) - avg_vel(3))/ &
@@ -3523,8 +3527,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dz(3) = 5d-1*(dvelL_dz_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dz_vf(3)%sf(j, k + 1, l))
+                            dvel_avg_dz(3) = 5e-1_wp*(dvelL_dz_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dz_vf(3)%sf(j, k + 1, l))
 
                             tau_Re(2, 2) = dvel_avg_dz(3)/y_cb(k)/ &
                                            Re_avg_rsy_vf(k, j, l, 2)
@@ -3555,28 +3559,28 @@ contains
 
                             !$acc loop seq
                             do i = 2, 3
-                                avg_vel(i) = 5d-1*(velL_vf(i)%sf(j, k, l) &
-                                                   + velR_vf(i)%sf(j, k, l + 1))
+                                avg_vel(i) = 5e-1_wp*(velL_vf(i)%sf(j, k, l) &
+                                                      + velR_vf(i)%sf(j, k, l + 1))
                             end do
 
                             !$acc loop seq
                             do i = 1, 3, 2
                                 dvel_avg_dx(i) = &
-                                    5d-1*(dvelL_dx_vf(i)%sf(j, k, l) &
-                                          + dvelR_dx_vf(i)%sf(j, k, l + 1))
+                                    5e-1_wp*(dvelL_dx_vf(i)%sf(j, k, l) &
+                                             + dvelR_dx_vf(i)%sf(j, k, l + 1))
                             end do
 
                             do i = 2, 3
                                 dvel_avg_dy(i) = &
-                                    5d-1*(dvelL_dy_vf(i)%sf(j, k, l) &
-                                          + dvelR_dy_vf(i)%sf(j, k, l + 1))
+                                    5e-1_wp*(dvelL_dy_vf(i)%sf(j, k, l) &
+                                             + dvelR_dy_vf(i)%sf(j, k, l + 1))
                             end do
 
                             !$acc loop seq
                             do i = 1, 3
                                 dvel_avg_dz(i) = &
-                                    5d-1*(dvelL_dz_vf(i)%sf(j, k, l) &
-                                          + dvelR_dz_vf(i)%sf(j, k, l + 1))
+                                    5e-1_wp*(dvelL_dz_vf(i)%sf(j, k, l) &
+                                             + dvelR_dz_vf(i)%sf(j, k, l + 1))
                             end do
 
                             tau_Re(3, 1) = (dvel_avg_dz(1)/y_cc(k) + dvel_avg_dx(3))/ &
@@ -3588,11 +3592,11 @@ contains
                                            Re_avg_rsz_vf(l, k, j, 1)/ &
                                            y_cc(k)
 
-                            tau_Re(3, 3) = (4d0*dvel_avg_dz(3)/y_cc(k) &
-                                            - 2d0*dvel_avg_dx(1) &
-                                            - 2d0*dvel_avg_dy(2) &
-                                            + 4d0*avg_vel(2)/y_cc(k))/ &
-                                           (3d0*Re_avg_rsz_vf(l, k, j, 1))/ &
+                            tau_Re(3, 3) = (4._wp*dvel_avg_dz(3)/y_cc(k) &
+                                            - 2._wp*dvel_avg_dx(1) &
+                                            - 2._wp*dvel_avg_dy(2) &
+                                            + 4._wp*avg_vel(2)/y_cc(k))/ &
+                                           (3._wp*Re_avg_rsz_vf(l, k, j, 1))/ &
                                            y_cc(k)
 
                             !$acc loop seq
@@ -3618,17 +3622,17 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            avg_vel(2) = 5d-1*(velL_vf(2)%sf(j, k, l) &
-                                               + velR_vf(2)%sf(j, k, l + 1))
+                            avg_vel(2) = 5e-1_wp*(velL_vf(2)%sf(j, k, l) &
+                                                  + velR_vf(2)%sf(j, k, l + 1))
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j, k, l + 1))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j, k, l + 1))
 
-                            dvel_avg_dy(2) = 5d-1*(dvelL_dy_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(2)%sf(j, k, l + 1))
+                            dvel_avg_dy(2) = 5e-1_wp*(dvelL_dy_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(2)%sf(j, k, l + 1))
 
-                            dvel_avg_dz(3) = 5d-1*(dvelL_dz_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dz_vf(3)%sf(j, k, l + 1))
+                            dvel_avg_dz(3) = 5e-1_wp*(dvelL_dz_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dz_vf(3)%sf(j, k, l + 1))
 
                             tau_Re(3, 3) = (dvel_avg_dx(1) &
                                             + dvel_avg_dy(2) &
@@ -3701,11 +3705,11 @@ contains
         ! Arithmetic mean of the left and right, WENO-reconstructed, cell-
         ! boundary values of cell-average first-order spatial derivatives
         ! of velocity
-        real(kind(0d0)), dimension(num_dims) :: dvel_avg_dx
-        real(kind(0d0)), dimension(num_dims) :: dvel_avg_dy
-        real(kind(0d0)), dimension(num_dims) :: dvel_avg_dz
+        real(wp), dimension(num_dims) :: dvel_avg_dx
+        real(wp), dimension(num_dims) :: dvel_avg_dy
+        real(wp), dimension(num_dims) :: dvel_avg_dz
 
-        real(kind(0d0)), dimension(num_dims, num_dims) :: tau_Re !< Viscous stress tensor
+        real(wp), dimension(num_dims, num_dims) :: tau_Re !< Viscous stress tensor
 
         integer :: i, j, k, l !< Generic loop iterators
 
@@ -3718,10 +3722,10 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j + 1, k, l))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j + 1, k, l))
 
-                            tau_Re(1, 1) = (4d0/3d0)*dvel_avg_dx(1)/ &
+                            tau_Re(1, 1) = (4._wp/3._wp)*dvel_avg_dx(1)/ &
                                            Re_avg_rsx_vf(j, k, l, 1)
 
                             flux_src_vf(momxb)%sf(j, k, l) = &
@@ -3744,8 +3748,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j + 1, k, l))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j + 1, k, l))
 
                             tau_Re(1, 1) = dvel_avg_dx(1)/ &
                                            Re_avg_rsx_vf(j, k, l, 2)
@@ -3775,14 +3779,14 @@ contains
                             !$acc loop seq
                             do i = 1, 2
                                 dvel_avg_dy(i) = &
-                                    5d-1*(dvelL_dy_vf(i)%sf(j, k, l) &
-                                          + dvelR_dy_vf(i)%sf(j + 1, k, l))
+                                    5e-1_wp*(dvelL_dy_vf(i)%sf(j, k, l) &
+                                             + dvelR_dy_vf(i)%sf(j + 1, k, l))
                             end do
 
-                            dvel_avg_dx(2) = 5d-1*(dvelL_dx_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(2)%sf(j + 1, k, l))
+                            dvel_avg_dx(2) = 5e-1_wp*(dvelL_dx_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(2)%sf(j + 1, k, l))
 
-                            tau_Re(1, 1) = -(2d0/3d0)*dvel_avg_dy(2)/ &
+                            tau_Re(1, 1) = -(2._wp/3._wp)*dvel_avg_dy(2)/ &
                                            Re_avg_rsx_vf(j, k, l, 1)
 
                             tau_Re(1, 2) = (dvel_avg_dy(1) + dvel_avg_dx(2))/ &
@@ -3813,8 +3817,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dy(2) = 5d-1*(dvelL_dy_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(2)%sf(j + 1, k, l))
+                            dvel_avg_dy(2) = 5e-1_wp*(dvelL_dy_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(2)%sf(j + 1, k, l))
 
                             tau_Re(1, 1) = dvel_avg_dy(2)/ &
                                            Re_avg_rsx_vf(j, k, l, 2)
@@ -3844,14 +3848,14 @@ contains
                             !$acc loop seq
                             do i = 1, 3, 2
                                 dvel_avg_dz(i) = &
-                                    5d-1*(dvelL_dz_vf(i)%sf(j, k, l) &
-                                          + dvelR_dz_vf(i)%sf(j + 1, k, l))
+                                    5e-1_wp*(dvelL_dz_vf(i)%sf(j, k, l) &
+                                             + dvelR_dz_vf(i)%sf(j + 1, k, l))
                             end do
 
-                            dvel_avg_dx(3) = 5d-1*(dvelL_dx_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(3)%sf(j + 1, k, l))
+                            dvel_avg_dx(3) = 5e-1_wp*(dvelL_dx_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(3)%sf(j + 1, k, l))
 
-                            tau_Re(1, 1) = -(2d0/3d0)*dvel_avg_dz(3)/ &
+                            tau_Re(1, 1) = -(2._wp/3._wp)*dvel_avg_dz(3)/ &
                                            Re_avg_rsx_vf(j, k, l, 1)
 
                             tau_Re(1, 3) = (dvel_avg_dz(1) + dvel_avg_dx(3))/ &
@@ -3881,8 +3885,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dz(3) = 5d-1*(dvelL_dz_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dz_vf(3)%sf(j + 1, k, l))
+                            dvel_avg_dz(3) = 5e-1_wp*(dvelL_dz_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dz_vf(3)%sf(j + 1, k, l))
 
                             tau_Re(1, 1) = dvel_avg_dz(3)/ &
                                            Re_avg_rsx_vf(j, k, l, 2)
@@ -3915,21 +3919,21 @@ contains
                             do i = 1, 2
 
                                 dvel_avg_dx(i) = &
-                                    5d-1*(dvelL_dx_vf(i)%sf(j, k, l) &
-                                          + dvelR_dx_vf(i)%sf(j, k + 1, l))
+                                    5e-1_wp*(dvelL_dx_vf(i)%sf(j, k, l) &
+                                             + dvelR_dx_vf(i)%sf(j, k + 1, l))
 
                                 dvel_avg_dy(i) = &
-                                    5d-1*(dvelL_dy_vf(i)%sf(j, k, l) &
-                                          + dvelR_dy_vf(i)%sf(j, k + 1, l))
+                                    5e-1_wp*(dvelL_dy_vf(i)%sf(j, k, l) &
+                                             + dvelR_dy_vf(i)%sf(j, k + 1, l))
 
                             end do
 
                             tau_Re(2, 1) = (dvel_avg_dy(1) + dvel_avg_dx(2))/ &
                                            Re_avg_rsy_vf(k, j, l, 1)
 
-                            tau_Re(2, 2) = (4d0*dvel_avg_dy(2) &
-                                            - 2d0*dvel_avg_dx(1))/ &
-                                           (3d0*Re_avg_rsy_vf(k, j, l, 1))
+                            tau_Re(2, 2) = (4._wp*dvel_avg_dy(2) &
+                                            - 2._wp*dvel_avg_dx(1))/ &
+                                           (3._wp*Re_avg_rsy_vf(k, j, l, 1))
 
                             !$acc loop seq
                             do i = 1, 2
@@ -3956,11 +3960,11 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j, k + 1, l))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j, k + 1, l))
 
-                            dvel_avg_dy(2) = 5d-1*(dvelL_dy_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(2)%sf(j, k + 1, l))
+                            dvel_avg_dy(2) = 5e-1_wp*(dvelL_dy_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(2)%sf(j, k + 1, l))
 
                             tau_Re(2, 2) = (dvel_avg_dx(1) + dvel_avg_dy(2))/ &
                                            Re_avg_rsy_vf(k, j, l, 2)
@@ -3990,14 +3994,14 @@ contains
                             !$acc loop seq
                             do i = 2, 3
                                 dvel_avg_dz(i) = &
-                                    5d-1*(dvelL_dz_vf(i)%sf(j, k, l) &
-                                          + dvelR_dz_vf(i)%sf(j, k + 1, l))
+                                    5e-1_wp*(dvelL_dz_vf(i)%sf(j, k, l) &
+                                             + dvelR_dz_vf(i)%sf(j, k + 1, l))
                             end do
 
-                            dvel_avg_dy(3) = 5d-1*(dvelL_dy_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(3)%sf(j, k + 1, l))
+                            dvel_avg_dy(3) = 5e-1_wp*(dvelL_dy_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(3)%sf(j, k + 1, l))
 
-                            tau_Re(2, 2) = -(2d0/3d0)*dvel_avg_dz(3)/ &
+                            tau_Re(2, 2) = -(2._wp/3._wp)*dvel_avg_dz(3)/ &
                                            Re_avg_rsy_vf(k, j, l, 1)
 
                             tau_Re(2, 3) = (dvel_avg_dz(2) + dvel_avg_dy(3))/ &
@@ -4028,8 +4032,8 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dz(3) = 5d-1*(dvelL_dz_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dz_vf(3)%sf(j, k + 1, l))
+                            dvel_avg_dz(3) = 5e-1_wp*(dvelL_dz_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dz_vf(3)%sf(j, k + 1, l))
 
                             tau_Re(2, 2) = dvel_avg_dz(3)/ &
                                            Re_avg_rsy_vf(k, j, l, 2)
@@ -4061,22 +4065,22 @@ contains
                             !$acc loop seq
                             do i = 1, 3, 2
                                 dvel_avg_dx(i) = &
-                                    5d-1*(dvelL_dx_vf(i)%sf(j, k, l) &
-                                          + dvelR_dx_vf(i)%sf(j, k, l + 1))
+                                    5e-1_wp*(dvelL_dx_vf(i)%sf(j, k, l) &
+                                             + dvelR_dx_vf(i)%sf(j, k, l + 1))
                             end do
 
                             !$acc loop seq
                             do i = 2, 3
                                 dvel_avg_dy(i) = &
-                                    5d-1*(dvelL_dy_vf(i)%sf(j, k, l) &
-                                          + dvelR_dy_vf(i)%sf(j, k, l + 1))
+                                    5e-1_wp*(dvelL_dy_vf(i)%sf(j, k, l) &
+                                             + dvelR_dy_vf(i)%sf(j, k, l + 1))
                             end do
 
                             !$acc loop seq
                             do i = 1, 3
                                 dvel_avg_dz(i) = &
-                                    5d-1*(dvelL_dz_vf(i)%sf(j, k, l) &
-                                          + dvelR_dz_vf(i)%sf(j, k, l + 1))
+                                    5e-1_wp*(dvelL_dz_vf(i)%sf(j, k, l) &
+                                             + dvelR_dz_vf(i)%sf(j, k, l + 1))
                             end do
 
                             tau_Re(3, 1) = (dvel_avg_dz(1) + dvel_avg_dx(3))/ &
@@ -4085,10 +4089,10 @@ contains
                             tau_Re(3, 2) = (dvel_avg_dz(2) + dvel_avg_dy(3))/ &
                                            Re_avg_rsz_vf(l, k, j, 1)
 
-                            tau_Re(3, 3) = (4d0*dvel_avg_dz(3) &
-                                            - 2d0*dvel_avg_dx(1) &
-                                            - 2d0*dvel_avg_dy(2))/ &
-                                           (3d0*Re_avg_rsz_vf(l, k, j, 1))
+                            tau_Re(3, 3) = (4._wp*dvel_avg_dz(3) &
+                                            - 2._wp*dvel_avg_dx(1) &
+                                            - 2._wp*dvel_avg_dy(2))/ &
+                                           (3._wp*Re_avg_rsz_vf(l, k, j, 1))
 
                             !$acc loop seq
                             do i = 1, 3
@@ -4115,14 +4119,14 @@ contains
                     do k = isy%beg, isy%end
                         do j = isx%beg, isx%end
 
-                            dvel_avg_dx(1) = 5d-1*(dvelL_dx_vf(1)%sf(j, k, l) &
-                                                   + dvelR_dx_vf(1)%sf(j, k, l + 1))
+                            dvel_avg_dx(1) = 5e-1_wp*(dvelL_dx_vf(1)%sf(j, k, l) &
+                                                      + dvelR_dx_vf(1)%sf(j, k, l + 1))
 
-                            dvel_avg_dy(2) = 5d-1*(dvelL_dy_vf(2)%sf(j, k, l) &
-                                                   + dvelR_dy_vf(2)%sf(j, k, l + 1))
+                            dvel_avg_dy(2) = 5e-1_wp*(dvelL_dy_vf(2)%sf(j, k, l) &
+                                                      + dvelR_dy_vf(2)%sf(j, k, l + 1))
 
-                            dvel_avg_dz(3) = 5d-1*(dvelL_dz_vf(3)%sf(j, k, l) &
-                                                   + dvelR_dz_vf(3)%sf(j, k, l + 1))
+                            dvel_avg_dz(3) = 5e-1_wp*(dvelL_dz_vf(3)%sf(j, k, l) &
+                                                      + dvelR_dz_vf(3)%sf(j, k, l + 1))
 
                             tau_Re(3, 3) = (dvel_avg_dx(1) &
                                             + dvel_avg_dy(2) &
diff --git a/src/simulation/m_sim_helpers.f90 b/src/simulation/m_sim_helpers.f90
index 2e94be868..f52b25e65 100644
--- a/src/simulation/m_sim_helpers.f90
+++ b/src/simulation/m_sim_helpers.f90
@@ -38,11 +38,11 @@ subroutine s_compute_enthalpy(q_prim_vf, pres, rho, gamma, pi_inf, Re, H, alpha,
 #endif
 
         type(scalar_field), dimension(sys_size) :: q_prim_vf
-        real(kind(0d0)), dimension(num_fluids) :: alpha_rho
-        real(kind(0d0)), dimension(num_fluids) :: alpha
-        real(kind(0d0)), dimension(num_dims) :: vel
-        real(kind(0d0)) :: rho, gamma, pi_inf, qv, vel_sum, E, H, pres
-        real(kind(0d0)), dimension(2) :: Re
+        real(wp), dimension(num_fluids) :: alpha_rho
+        real(wp), dimension(num_fluids) :: alpha
+        real(wp), dimension(num_dims) :: vel
+        real(wp) :: rho, gamma, pi_inf, qv, vel_sum, E, H, pres
+        real(wp), dimension(2) :: Re
         integer :: i, j, k, l
 
         do i = 1, num_fluids
@@ -60,14 +60,14 @@ subroutine s_compute_enthalpy(q_prim_vf, pres, rho, gamma, pi_inf, Re, H, alpha,
             vel(i) = q_prim_vf(contxe + i)%sf(j, k, l)
         end do
 
-        vel_sum = 0d0
+        vel_sum = 0._wp
         do i = 1, num_dims
-            vel_sum = vel_sum + vel(i)**2d0
+            vel_sum = vel_sum + vel(i)**2._wp
         end do
 
         pres = q_prim_vf(E_idx)%sf(j, k, l)
 
-        E = gamma*pres + pi_inf + 5d-1*rho*vel_sum + qv
+        E = gamma*pres + pi_inf + 5e-1_wp*rho*vel_sum + qv
 
         H = (E + pres)/rho
 
@@ -85,22 +85,22 @@ end subroutine s_compute_enthalpy
         !! @param Rc_sf (optional) cell centered Rc
     subroutine s_compute_stability_from_dt(vel, c, rho, Re_l, j, k, l, icfl_sf, vcfl_sf, Rc_sf)
         !$acc routine seq
-        real(kind(0d0)), dimension(num_dims) :: vel
-        real(kind(0d0)) :: c, rho
-        real(kind(0d0)), dimension(0:m, 0:n, 0:p) :: icfl_sf
-        real(kind(0d0)), dimension(0:m, 0:n, 0:p), optional :: vcfl_sf, Rc_sf
-        real(kind(0d0)) :: fltr_dtheta   !<
+        real(wp), dimension(num_dims) :: vel
+        real(wp) :: c, rho
+        real(wp), dimension(0:m, 0:n, 0:p) :: icfl_sf
+        real(wp), dimension(0:m, 0:n, 0:p), optional :: vcfl_sf, Rc_sf
+        real(wp) :: fltr_dtheta   !<
              !! Modified dtheta accounting for Fourier filtering in azimuthal direction.
         integer :: j, k, l
         integer :: Nfq
-        real(kind(0d0)), dimension(2) :: Re_l
+        real(wp), dimension(2) :: Re_l
 
         if (grid_geometry == 3) then
             if (k == 0) then
-                fltr_dtheta = 2d0*pi*y_cb(0)/3d0
+                fltr_dtheta = 2._wp*pi*y_cb(0)/3._wp
             elseif (k <= fourier_rings) then
-                Nfq = min(floor(2d0*real(k, kind(0d0))*pi), (p + 1)/2 + 1)
-                fltr_dtheta = 2d0*pi*y_cb(k - 1)/real(Nfq, kind(0d0))
+                Nfq = min(floor(2._wp*real(k, wp)*pi), (p + 1)/2 + 1)
+                fltr_dtheta = 2._wp*pi*y_cb(k - 1)/real(Nfq, wp)
             else
                 fltr_dtheta = y_cb(k - 1)*dz(l)
             end if
@@ -122,20 +122,20 @@ subroutine s_compute_stability_from_dt(vel, c, rho, Re_l, j, k, l, icfl_sf, vcfl
 
                 if (grid_geometry == 3) then
                     vcfl_sf(j, k, l) = maxval(dt/Re_l/rho) &
-                                       /min(dx(j), dy(k), fltr_dtheta)**2d0
+                                       /min(dx(j), dy(k), fltr_dtheta)**2._wp
 
                     Rc_sf(j, k, l) = min(dx(j)*(abs(vel(1)) + c), &
                                          dy(k)*(abs(vel(2)) + c), &
                                          fltr_dtheta*(abs(vel(3)) + c)) &
-                                     /maxval(1d0/Re_l)
+                                     /maxval(1._wp/Re_l)
                 else
                     vcfl_sf(j, k, l) = maxval(dt/Re_l/rho) &
-                                       /min(dx(j), dy(k), dz(l))**2d0
+                                       /min(dx(j), dy(k), dz(l))**2._wp
 
                     Rc_sf(j, k, l) = min(dx(j)*(abs(vel(1)) + c), &
                                          dy(k)*(abs(vel(2)) + c), &
                                          dz(l)*(abs(vel(3)) + c)) &
-                                     /maxval(1d0/Re_l)
+                                     /maxval(1._wp/Re_l)
                 end if
 
             end if
@@ -147,11 +147,11 @@ subroutine s_compute_stability_from_dt(vel, c, rho, Re_l, j, k, l, icfl_sf, vcfl
 
             if (viscous) then
 
-                vcfl_sf(j, k, l) = maxval(dt/Re_l/rho)/min(dx(j), dy(k))**2d0
+                vcfl_sf(j, k, l) = maxval(dt/Re_l/rho)/min(dx(j), dy(k))**2._wp
 
                 Rc_sf(j, k, l) = min(dx(j)*(abs(vel(1)) + c), &
                                      dy(k)*(abs(vel(2)) + c)) &
-                                 /maxval(1d0/Re_l)
+                                 /maxval(1._wp/Re_l)
 
             end if
 
@@ -161,9 +161,9 @@ subroutine s_compute_stability_from_dt(vel, c, rho, Re_l, j, k, l, icfl_sf, vcfl
 
             if (viscous) then
 
-                vcfl_sf(j, k, l) = maxval(dt/Re_l/rho)/dx(j)**2d0
+                vcfl_sf(j, k, l) = maxval(dt/Re_l/rho)/dx(j)**2._wp
 
-                Rc_sf(j, k, l) = dx(j)*(abs(vel(1)) + c)/maxval(1d0/Re_l)
+                Rc_sf(j, k, l) = dx(j)*(abs(vel(1)) + c)/maxval(1._wp/Re_l)
 
             end if
 
@@ -181,21 +181,21 @@ end subroutine s_compute_stability_from_dt
         !! @param l z coordinate
     subroutine s_compute_dt_from_cfl(vel, c, max_dt, rho, Re_l, j, k, l)
         !$acc routine seq
-        real(kind(0d0)), dimension(num_dims) :: vel
-        real(kind(0d0)) :: c, icfl_dt, vcfl_dt, rho
-        real(kind(0d0)), dimension(0:m, 0:n, 0:p) :: max_dt
-        real(kind(0d0)) :: fltr_dtheta   !<
+        real(wp), dimension(num_dims) :: vel
+        real(wp) :: c, icfl_dt, vcfl_dt, rho
+        real(wp), dimension(0:m, 0:n, 0:p) :: max_dt
+        real(wp) :: fltr_dtheta   !<
              !! Modified dtheta accounting for Fourier filtering in azimuthal direction.
         integer :: j, k, l
         integer :: Nfq
-        real(kind(0d0)), dimension(2) :: Re_l
+        real(wp), dimension(2) :: Re_l
 
         if (grid_geometry == 3) then
             if (k == 0) then
-                fltr_dtheta = 2d0*pi*y_cb(0)/3d0
+                fltr_dtheta = 2._wp*pi*y_cb(0)/3._wp
             elseif (k <= fourier_rings) then
-                Nfq = min(floor(2d0*real(k, kind(0d0))*pi), (p + 1)/2 + 1)
-                fltr_dtheta = 2d0*pi*y_cb(k - 1)/real(Nfq, kind(0d0))
+                Nfq = min(floor(2._wp*real(k, wp)*pi), (p + 1)/2 + 1)
+                fltr_dtheta = 2._wp*pi*y_cb(k - 1)/real(Nfq, wp)
             else
                 fltr_dtheta = y_cb(k - 1)*dz(l)
             end if
@@ -215,10 +215,10 @@ subroutine s_compute_dt_from_cfl(vel, c, max_dt, rho, Re_l, j, k, l)
 
             if (viscous) then
                 if (grid_geometry == 3) then
-                    vcfl_dt = cfl_target*(min(dx(j), dy(k), fltr_dtheta)**2d0) &
+                    vcfl_dt = cfl_target*(min(dx(j), dy(k), fltr_dtheta)**2._wp) &
                               /minval(1/(rho*Re_l))
                 else
-                    vcfl_dt = cfl_target*(min(dx(j), dy(k), dz(l))**2d0) &
+                    vcfl_dt = cfl_target*(min(dx(j), dy(k), dz(l))**2._wp) &
                               /minval(1/(rho*Re_l))
                 end if
             end if
@@ -229,7 +229,7 @@ subroutine s_compute_dt_from_cfl(vel, c, max_dt, rho, Re_l, j, k, l)
                                      dy(k)/(abs(vel(2)) + c))
 
             if (viscous) then
-                vcfl_dt = cfl_target*(min(dx(j), dy(k))**2d0)/maxval((1/Re_l)/rho)
+                vcfl_dt = cfl_target*(min(dx(j), dy(k))**2._wp)/maxval((1/Re_l)/rho)
             end if
 
         else
@@ -237,7 +237,7 @@ subroutine s_compute_dt_from_cfl(vel, c, max_dt, rho, Re_l, j, k, l)
             icfl_dt = cfl_target*(dx(j)/(abs(vel(1)) + c))
 
             if (viscous) then
-                vcfl_dt = cfl_target*(dx(j)**2d0)/minval(1/(rho*Re_l))
+                vcfl_dt = cfl_target*(dx(j)**2._wp)/minval(1/(rho*Re_l))
             end if
 
         end if
diff --git a/src/simulation/m_start_up.fpp b/src/simulation/m_start_up.fpp
index 2d6611d65..d2de693ec 100644
--- a/src/simulation/m_start_up.fpp
+++ b/src/simulation/m_start_up.fpp
@@ -36,7 +36,7 @@ module m_start_up
 
     use m_acoustic_src      !< Acoustic source calculations
 
-    use m_rhs                  !< Right-hand-side (RHS) evaluation procedures
+    use m_rhs                  !< Right-hane-side (RHS) evaluation procedures
 
     use m_chemistry            !< Chemistry module
 
@@ -97,7 +97,7 @@ module m_start_up
 
     type(scalar_field), allocatable, dimension(:) :: grad_x_vf, grad_y_vf, grad_z_vf, norm_vf
 
-    real(kind(0d0)) :: dt_init
+    real(wp) :: dt_init
 
 contains
 
@@ -109,6 +109,7 @@ contains
             dimension(sys_size), &
             intent(inout) :: q_cons_vf
 
+
         if (.not. parallel_io) then
             call s_read_serial_data_files(q_cons_vf)
         else
@@ -285,7 +286,7 @@ contains
         end if
 
         dx(0:m) = x_cb(0:m) - x_cb(-1:m - 1)
-        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2d0
+        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2._wp
 
         if (ib) then
             do i = 1, num_ibs
@@ -314,7 +315,7 @@ contains
             end if
 
             dy(0:n) = y_cb(0:n) - y_cb(-1:n - 1)
-            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2d0
+            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2._wp
 
         end if
         ! ==================================================================
@@ -337,7 +338,7 @@ contains
             end if
 
             dz(0:p) = z_cb(0:p) - z_cb(-1:p - 1)
-            z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2d0
+            z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2._wp
 
         end if
         ! ==================================================================
@@ -488,7 +489,7 @@ contains
 
 #ifdef MFC_MPI
 
-        real(kind(0d0)), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb
+        real(wp), allocatable, dimension(:) :: x_cb_glb, y_cb_glb, z_cb_glb
 
         integer :: ifile, ierr, data_size
         integer, dimension(MPI_STATUS_SIZE) :: status
@@ -516,7 +517,7 @@ contains
         if (file_exist) then
             data_size = m_glb + 2
             call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-            call MPI_FILE_READ(ifile, x_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+            call MPI_FILE_READ(ifile, x_cb_glb, data_size, mpi_p, status, ierr)
             call MPI_FILE_CLOSE(ifile, ierr)
         else
             call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -527,7 +528,7 @@ contains
         ! Computing the cell width distribution
         dx(0:m) = x_cb(0:m) - x_cb(-1:m - 1)
         ! Computing the cell center locations
-        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2d0
+        x_cc(0:m) = x_cb(-1:m - 1) + dx(0:m)/2._wp
 
         if (ib) then
             do i = 1, num_ibs
@@ -547,7 +548,7 @@ contains
             if (file_exist) then
                 data_size = n_glb + 2
                 call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-                call MPI_FILE_READ(ifile, y_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                call MPI_FILE_READ(ifile, y_cb_glb, data_size, mpi_p, status, ierr)
                 call MPI_FILE_CLOSE(ifile, ierr)
             else
                 call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -558,7 +559,7 @@ contains
             ! Computing the cell width distribution
             dy(0:n) = y_cb(0:n) - y_cb(-1:n - 1)
             ! Computing the cell center locations
-            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2d0
+            y_cc(0:n) = y_cb(-1:n - 1) + dy(0:n)/2._wp
 
             if (p > 0) then
                 ! Read in cell boundary locations in z-direction
@@ -568,7 +569,7 @@ contains
                 if (file_exist) then
                     data_size = p_glb + 2
                     call MPI_FILE_OPEN(MPI_COMM_WORLD, file_loc, MPI_MODE_RDONLY, mpi_info_int, ifile, ierr)
-                    call MPI_FILE_READ(ifile, z_cb_glb, data_size, MPI_DOUBLE_PRECISION, status, ierr)
+                    call MPI_FILE_READ(ifile, z_cb_glb, data_size, mpi_p, status, ierr)
                     call MPI_FILE_CLOSE(ifile, ierr)
                 else
                     call s_mpi_abort('File '//trim(file_loc)//'is missing. Exiting...')
@@ -579,7 +580,7 @@ contains
                 ! Computing the cell width distribution
                 dz(0:p) = z_cb(0:p) - z_cb(-1:p - 1)
                 ! Computing the cell center locations
-                z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2d0
+                z_cc(0:p) = z_cb(-1:p - 1) + dz(0:p)/2._wp
 
             end if
         end if
@@ -614,8 +615,8 @@ contains
                 m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
                 n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
                 p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-                WP_MOK = int(8d0, MPI_OFFSET_KIND)
-                MOK = int(1d0, MPI_OFFSET_KIND)
+                WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+                MOK = int(1._wp, MPI_OFFSET_KIND)
                 str_MOK = int(name_len, MPI_OFFSET_KIND)
                 NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -626,7 +627,7 @@ contains
                         var_MOK = int(i, MPI_OFFSET_KIND)
 
                         call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
                     end do
                     !Read pb and mv for non-polytropic qbmm
                     if (qbmm .and. .not. polytropic) then
@@ -634,7 +635,7 @@ contains
                             var_MOK = int(i, MPI_OFFSET_KIND)
 
                             call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                               MPI_DOUBLE_PRECISION, status, ierr)
+                                               mpi_p, status, ierr)
                         end do
                     end if
                 else
@@ -642,7 +643,7 @@ contains
                         var_MOK = int(i, MPI_OFFSET_KIND)
 
                         call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
                     end do
                 end if
 
@@ -682,10 +683,10 @@ contains
 
                         disp = 0
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_levelset_DATA%view, &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_levelset_DATA%view, &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_levelset_DATA%var%sf, data_size * num_ibs, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
 
                     else
                         call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -702,10 +703,10 @@ contains
 
                         disp = 0
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_levelsetnorm_DATA%view, &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_levelsetnorm_DATA%view, &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_levelsetnorm_DATA%var%sf, data_size * num_ibs * 3, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
 
                     else
                         call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -749,8 +750,8 @@ contains
                 m_MOK = int(m_glb + 1, MPI_OFFSET_KIND)
                 n_MOK = int(n_glb + 1, MPI_OFFSET_KIND)
                 p_MOK = int(p_glb + 1, MPI_OFFSET_KIND)
-                WP_MOK = int(8d0, MPI_OFFSET_KIND)
-                MOK = int(1d0, MPI_OFFSET_KIND)
+                WP_MOK = int(8._wp, MPI_OFFSET_KIND)
+                MOK = int(1._wp, MPI_OFFSET_KIND)
                 str_MOK = int(name_len, MPI_OFFSET_KIND)
                 NVARS_MOK = int(sys_size, MPI_OFFSET_KIND)
 
@@ -762,10 +763,10 @@ contains
                         ! Initial displacement to skip at beginning of file
                         disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
                     end do
                     !Read pb and mv for non-polytropic qbmm
                     if (qbmm .and. .not. polytropic) then
@@ -774,10 +775,10 @@ contains
                             ! Initial displacement to skip at beginning of file
                             disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                            call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                            call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                    'native', mpi_info_int, ierr)
                             call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                               MPI_DOUBLE_PRECISION, status, ierr)
+                                               mpi_p, status, ierr)
                         end do
                     end if
                 else
@@ -787,10 +788,10 @@ contains
                         ! Initial displacement to skip at beginning of file
                         disp = m_MOK*max(MOK, n_MOK)*max(MOK, p_MOK)*WP_MOK*(var_MOK - 1)
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_DATA%view(i), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_DATA%view(i), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_DATA%var(i)%sf, data_size, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
 
                     end do
                 end if
@@ -832,10 +833,10 @@ contains
 
                         disp = 0
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_levelset_DATA%view, &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_levelset_DATA%view, &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_levelset_DATA%var%sf, data_size, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
 
                     else
                         call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -852,10 +853,10 @@ contains
 
                         disp = 0
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_levelsetnorm_DATA%view, &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_levelsetnorm_DATA%view, &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_levelsetnorm_DATA%var%sf, data_size * num_ibs * 3, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
 
                     else
                         call s_mpi_abort('File '//trim(file_loc)//' is missing. Exiting...')
@@ -889,10 +890,10 @@ contains
                         ! Initial displacement to skip at beginning of file
                         disp = 0
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_airfoil_IB_DATA%view(1), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_airfoil_IB_DATA%view(1), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_airfoil_IB_DATA%var(1:Np), 3*Np, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
 
                     end if
 
@@ -906,10 +907,10 @@ contains
                         ! Initial displacement to skip at beginning of file
                         disp = 0
 
-                        call MPI_FILE_SET_VIEW(ifile, disp, MPI_DOUBLE_PRECISION, MPI_IO_airfoil_IB_DATA%view(2), &
+                        call MPI_FILE_SET_VIEW(ifile, disp, mpi_p, MPI_IO_airfoil_IB_DATA%view(2), &
                                                'native', mpi_info_int, ierr)
                         call MPI_FILE_READ(ifile, MPI_IO_airfoil_IB_DATA%var(Np + 1:2*Np), 3*Np, &
-                                           MPI_DOUBLE_PRECISION, status, ierr)
+                                           mpi_p, status, ierr)
                     end if
 
                     do i = 1, Np
@@ -970,7 +971,7 @@ contains
         ! Computing the cell-center locations buffer, at the beginning of
         ! the coordinate direction, from the cell-width distribution buffer
         do i = 1, buff_size
-            x_cc(-i) = x_cc(1 - i) - (dx(1 - i) + dx(-i))/2d0
+            x_cc(-i) = x_cc(1 - i) - (dx(1 - i) + dx(-i))/2._wp
         end do
 
         ! Populating the cell-width distribution buffer, at the end of the
@@ -1001,7 +1002,7 @@ contains
         ! Populating the cell-center locations buffer, at the end of the
         ! coordinate direction, from buffer of the cell-width distribution
         do i = 1, buff_size
-            x_cc(m + i) = x_cc(m + (i - 1)) + (dx(m + (i - 1)) + dx(m + i))/2d0
+            x_cc(m + i) = x_cc(m + (i - 1)) + (dx(m + (i - 1)) + dx(m + i))/2._wp
         end do
 
         ! END: Population of Buffers in x-direction ========================
@@ -1038,7 +1039,7 @@ contains
         ! Computing the cell-center locations buffer, at the beginning of
         ! the coordinate direction, from the cell-width distribution buffer
         do i = 1, buff_size
-            y_cc(-i) = y_cc(1 - i) - (dy(1 - i) + dy(-i))/2d0
+            y_cc(-i) = y_cc(1 - i) - (dy(1 - i) + dy(-i))/2._wp
         end do
 
         ! Populating the cell-width distribution buffer, at the end of the
@@ -1069,7 +1070,7 @@ contains
         ! Populating the cell-center locations buffer, at the end of the
         ! coordinate direction, from buffer of the cell-width distribution
         do i = 1, buff_size
-            y_cc(n + i) = y_cc(n + (i - 1)) + (dy(n + (i - 1)) + dy(n + i))/2d0
+            y_cc(n + i) = y_cc(n + (i - 1)) + (dy(n + (i - 1)) + dy(n + i))/2._wp
         end do
 
         ! END: Population of Buffers in y-direction ========================
@@ -1106,7 +1107,7 @@ contains
         ! Computing the cell-center locations buffer, at the beginning of
         ! the coordinate direction, from the cell-width distribution buffer
         do i = 1, buff_size
-            z_cc(-i) = z_cc(1 - i) - (dz(1 - i) + dz(-i))/2d0
+            z_cc(-i) = z_cc(1 - i) - (dz(1 - i) + dz(-i))/2._wp
         end do
 
         ! Populating the cell-width distribution buffer, at the end of the
@@ -1137,7 +1138,7 @@ contains
         ! Populating the cell-center locations buffer, at the end of the
         ! coordinate direction, from buffer of the cell-width distribution
         do i = 1, buff_size
-            z_cc(p + i) = z_cc(p + (i - 1)) + (dz(p + (i - 1)) + dz(p + i))/2d0
+            z_cc(p + i) = z_cc(p + (i - 1)) + (dz(p + (i - 1)) + dz(p + i))/2._wp
         end do
 
         ! END: Population of Buffers in z-direction ========================
@@ -1153,17 +1154,17 @@ contains
 
         type(scalar_field), dimension(sys_size), intent(inout) :: v_vf
 
-        real(kind(0d0)) :: rho
-        real(kind(0d0)) :: dyn_pres
-        real(kind(0d0)) :: gamma
-        real(kind(0d0)) :: pi_inf
-        real(kind(0d0)) :: qv
-        real(kind(0d0)), dimension(2) :: Re
-        real(kind(0d0)) :: pres, T
+        real(wp) :: rho
+        real(wp) :: dyn_pres
+        real(wp) :: gamma
+        real(wp) :: pi_inf
+        real(wp) :: qv
+        real(wp), dimension(2) :: Re
+        real(wp) :: pres, T
 
         integer :: i, j, k, l, c
 
-        real(kind(0d0)), dimension(num_species) :: rhoYks
+        real(wp), dimension(num_species) :: rhoYks
 
         do j = 0, m
             do k = 0, n
@@ -1171,9 +1172,9 @@ contains
 
                     call s_convert_to_mixture_variables(v_vf, j, k, l, rho, gamma, pi_inf, qv, Re)
 
-                    dyn_pres = 0d0
+                    dyn_pres = 0._wp
                     do i = mom_idx%beg, mom_idx%end
-                        dyn_pres = dyn_pres + 5d-1*v_vf(i)%sf(j, k, l)*v_vf(i)%sf(j, k, l) &
+                        dyn_pres = dyn_pres + 5e-1_wp*v_vf(i)%sf(j, k, l)*v_vf(i)%sf(j, k, l) &
                                    /max(rho, sgm_eps)
                     end do
 
@@ -1183,7 +1184,8 @@ contains
                         end do
                     end if
 
-                    call s_compute_pressure(v_vf(E_idx)%sf(j, k, l), 0d0, &
+
+                    call s_compute_pressure(v_vf(E_idx)%sf(j, k, l), 0._wp, &
                                             dyn_pres, pi_inf, gamma, rho, qv, rhoYks, pres, T)
 
                     do i = 1, num_fluids
@@ -1200,14 +1202,15 @@ contains
 
     subroutine s_perform_time_step(t_step, time_avg, time_final, io_time_avg, io_time_final, proc_time, io_proc_time, file_exists, start, finish, nt)
         integer, intent(inout) :: t_step
-        real(kind(0d0)), intent(inout) :: time_avg, time_final
-        real(kind(0d0)), intent(inout) :: io_time_avg, io_time_final
-        real(kind(0d0)), dimension(:), intent(inout) :: proc_time
-        real(kind(0d0)), dimension(:), intent(inout) :: io_proc_time
+        real(wp), intent(inout) :: time_avg, time_final
+        real(wp), intent(inout) :: io_time_avg, io_time_final
+        real(wp), dimension(:), intent(inout) :: proc_time
+        real(wp), dimension(:), intent(inout) :: io_proc_time
         logical, intent(inout) :: file_exists
-        real(kind(0d0)), intent(inout) :: start, finish
+        real(wp), intent(inout) :: start, finish
         integer, intent(inout) :: nt
 
+
         integer :: i
 
         if (cfl_dt) then
@@ -1217,7 +1220,7 @@ contains
 
             if (t_step == 0) dt_init = dt
 
-            if (dt < 1d-3*dt_init .and. cfl_adap_dt .and. proc_rank == 0) then
+            if (dt < 1e-3_wp*dt_init .and. cfl_adap_dt .and. proc_rank == 0) then
                 print*, "Delta t = ", dt
                 call s_mpi_abort("Delta t has become too small")
             end if
@@ -1232,7 +1235,7 @@ contains
         if (cfl_dt) then
             if (proc_rank == 0 .and. mod(t_step - t_step_start, t_step_print) == 0) then
                 print '(" ["I3"%] Time "ES16.6" dt = "ES16.6" @ Time Step = "I8"")', &
-                    int(ceiling(100d0*(mytime/t_stop))), &
+                    int(ceiling(100._wp*(mytime/t_stop))), &
                     mytime, &
                     dt, &
                     t_step
@@ -1240,7 +1243,7 @@ contains
         else
             if (proc_rank == 0 .and. mod(t_step - t_step_start, t_step_print) == 0) then
                 print '(" ["I3"%]  Time step "I8" of "I0" @ t_step = "I0"")', &
-                   int(ceiling(100d0*(real(t_step - t_step_start)/(t_step_stop - t_step_start + 1)))), &
+                   int(ceiling(100._wp*(real(t_step - t_step_start)/(t_step_stop - t_step_start + 1)))), &
                     t_step - t_step_start + 1, &
                     t_step_stop - t_step_start + 1, &
                 t_step
@@ -1283,15 +1286,15 @@ contains
     subroutine s_save_performance_metrics(t_step, time_avg, time_final, io_time_avg, io_time_final, proc_time, io_proc_time, file_exists, start, finish, nt)
 
         integer, intent(inout) :: t_step
-        real(kind(0d0)), intent(inout) :: time_avg, time_final
-        real(kind(0d0)), intent(inout) :: io_time_avg, io_time_final
-        real(kind(0d0)), dimension(:), intent(inout) :: proc_time
-        real(kind(0d0)), dimension(:), intent(inout) :: io_proc_time
+        real(wp), intent(inout) :: time_avg, time_final
+        real(wp), intent(inout) :: io_time_avg, io_time_final
+        real(wp), dimension(:), intent(inout) :: proc_time
+        real(wp), dimension(:), intent(inout) :: io_proc_time
         logical, intent(inout) :: file_exists
-        real(kind(0d0)), intent(inout) :: start, finish
+        real(wp), intent(inout) :: start, finish
         integer, intent(inout) :: nt
 
-        real(kind(0d0)) :: grind_time
+        real(wp) :: grind_time
 
         call s_mpi_barrier()
 
@@ -1302,8 +1305,8 @@ contains
         end if
 
         if (proc_rank == 0) then
-            time_final = 0d0
-            io_time_final = 0d0
+            time_final = 0._wp
+            io_time_final = 0._wp
             if (num_procs == 1) then
                 time_final = time_avg
                 io_time_final = io_time_avg
@@ -1312,7 +1315,7 @@ contains
                 io_time_final = maxval(io_proc_time)
             end if
 
-            grind_time = time_final*1.0d9/(sys_size*maxval((/1,m_glb/))*maxval((/1,n_glb/))*maxval((/1,p_glb/)))
+            grind_time = time_final*1.0e9_wp/(sys_size*maxval((/1,m_glb/))*maxval((/1,n_glb/))*maxval((/1,p_glb/)))
 
             print *, "Performance:", grind_time, "ns/gp/eq/rhs"
             inquire (FILE='time_data.dat', EXIST=file_exists)
@@ -1344,7 +1347,7 @@ contains
 
     subroutine s_save_data(t_step, start, finish, io_time_avg, nt)
         integer, intent(inout) :: t_step
-        real(kind(0d0)), intent(inout) :: start, finish, io_time_avg
+        real(wp), intent(inout) :: start, finish, io_time_avg
         integer, intent(inout) :: nt
 
         integer :: i, j, k, l
@@ -1408,9 +1411,9 @@ contains
         end if
         !Initialize pb based on surface tension for qbmm (polytropic)
         if (qbmm .and. polytropic .and. (.not. f_is_default(Web))) then
-            pb0 = pref + 2d0*fluid_pp(1)%ss/(R0*R0ref)
+            pb0 = pref + 2._wp*fluid_pp(1)%ss/(R0*R0ref)
             pb0 = pb0/pref
-            pref = 1d0
+            pref = 1._wp
         end if
 
 #if defined(MFC_OpenACC) && defined(MFC_MEMORY_DUMP)
@@ -1488,7 +1491,7 @@ contains
     subroutine s_initialize_mpi_domain
         integer :: ierr
 #ifdef MFC_OpenACC
-        real(kind(0d0)) :: starttime, endtime
+        real(wp) :: starttime, endtime
         integer :: num_devices, local_size, num_nodes, ppn, my_device_num
         integer :: dev, devNum, local_rank
 #ifdef MFC_MPI
diff --git a/src/simulation/m_surface_tension.fpp b/src/simulation/m_surface_tension.fpp
index 85176a99a..8a771a27c 100644
--- a/src/simulation/m_surface_tension.fpp
+++ b/src/simulation/m_surface_tension.fpp
@@ -36,7 +36,7 @@ module m_surface_tension
 
     !> @name cell boundary reconstructed gradient components and magnitude
     !> @{
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: gL_x, gR_x, gL_y, gR_y, gL_z, gR_z
+    real(wp), allocatable, dimension(:, :, :, :) :: gL_x, gR_x, gL_y, gR_y, gL_z, gR_z
     !> @}
     !$acc declare create(gL_x, gR_x, gL_y, gR_y, gL_z, gR_z)
 
@@ -74,18 +74,18 @@ contains
                                               id, isx, isy, isz)
 
         type(scalar_field), dimension(sys_size) :: q_prim_vf !> unused so unsure what intent to give it
-        real(kind(0d0)), dimension(-1:, 0:, 0:, 1:), intent(in) :: vSrc_rsx_vf
-        real(kind(0d0)), dimension(-1:, 0:, 0:, 1:), intent(in) :: vSrc_rsy_vf
-        real(kind(0d0)), dimension(-1:, 0:, 0:, 1:), intent(in) :: vSrc_rsz_vf
+        real(wp), dimension(-1:, 0:, 0:, 1:), intent(in) :: vSrc_rsx_vf
+        real(wp), dimension(-1:, 0:, 0:, 1:), intent(in) :: vSrc_rsy_vf
+        real(wp), dimension(-1:, 0:, 0:, 1:), intent(in) :: vSrc_rsz_vf
         type(scalar_field), &
             dimension(sys_size), &
             intent(inout) :: flux_src_vf
         integer, intent(in) :: id
         type(int_bounds_info), intent(in) :: isx, isy, isz
 
-        real(kind(0d0)), dimension(num_dims, num_dims) :: Omega
-        real(kind(0d0)) :: w1L, w1R, w2L, w2R, w3L, w3R, w1, w2, w3
-        real(kind(0d0)) :: normWL, normWR, normW
+        real(wp), dimension(num_dims, num_dims) :: Omega
+        real(wp) :: w1L, w1R, w2L, w2R, w3L, w3R, w1, w2, w3
+        real(wp) :: normWL, normWR, normW
 
         if (id == 1) then
             !$acc parallel loop collapse(3) gang vector default(present) private(Omega, &
@@ -96,21 +96,21 @@ contains
 
                         w1L = gL_x(j, k, l, 1)
                         w2L = gL_x(j, k, l, 2)
-                        w3L = 0d0
+                        w3L = 0._wp
                         if (p > 0) w3L = gL_x(j, k, l, 3)
 
                         w1R = gR_x(j + 1, k, l, 1)
                         w2R = gR_x(j + 1, k, l, 2)
-                        w3R = 0d0
+                        w3R = 0._wp
                         if (p > 0) w3R = gR_x(j + 1, k, l, 3)
 
                         normWL = gL_x(j, k, l, num_dims + 1)
                         normWR = gR_x(j + 1, k, l, num_dims + 1)
 
-                        w1 = (w1L + w1R)/2d0
-                        w2 = (w2L + w2R)/2d0
-                        w3 = (w3L + w3R)/2d0
-                        normW = (normWL + normWR)/2d0
+                        w1 = (w1L + w1R)/2._wp
+                        w2 = (w2L + w2R)/2._wp
+                        w3 = (w3L + w3R)/2._wp
+                        normW = (normWL + normWR)/2._wp
 
                         if (normW > capillary_cutoff) then
                             @:compute_capilary_stress_tensor()
@@ -142,21 +142,21 @@ contains
 
                         w1L = gL_y(k, j, l, 1)
                         w2L = gL_y(k, j, l, 2)
-                        w3L = 0d0
+                        w3L = 0._wp
                         if (p > 0) w3L = gL_y(k, j, l, 3)
 
                         w1R = gR_y(k + 1, j, l, 1)
                         w2R = gR_y(k + 1, j, l, 2)
-                        w3R = 0d0
+                        w3R = 0._wp
                         if (p > 0) w3R = gR_y(k + 1, j, l, 3)
 
                         normWL = gL_y(k, j, l, num_dims + 1)
                         normWR = gR_y(k + 1, j, l, num_dims + 1)
 
-                        w1 = (w1L + w1R)/2d0
-                        w2 = (w2L + w2R)/2d0
-                        w3 = (w3L + w3R)/2d0
-                        normW = (normWL + normWR)/2d0
+                        w1 = (w1L + w1R)/2._wp
+                        w2 = (w2L + w2R)/2._wp
+                        w3 = (w3L + w3R)/2._wp
+                        normW = (normWL + normWR)/2._wp
 
                         if (normW > capillary_cutoff) then
                             @:compute_capilary_stress_tensor()
@@ -188,21 +188,21 @@ contains
 
                         w1L = gL_z(l, k, j, 1)
                         w2L = gL_z(l, k, j, 2)
-                        w3L = 0d0
+                        w3L = 0._wp
                         if (p > 0) w3L = gL_z(l, k, j, 3)
 
                         w1R = gR_z(l + 1, k, j, 1)
                         w2R = gR_z(l + 1, k, j, 2)
-                        w3R = 0d0
+                        w3R = 0._wp
                         if (p > 0) w3R = gR_z(l + 1, k, j, 3)
 
                         normWL = gL_z(l, k, j, num_dims + 1)
                         normWR = gR_z(l + 1, k, j, num_dims + 1)
 
-                        w1 = (w1L + w1R)/2d0
-                        w2 = (w2L + w2R)/2d0
-                        w3 = (w3L + w3R)/2d0
-                        normW = (normWL + normWR)/2d0
+                        w1 = (w1L + w1R)/2._wp
+                        w2 = (w2L + w2R)/2._wp
+                        w3 = (w3L + w3R)/2._wp
+                        normW = (normWL + normWR)/2._wp
 
                         if (normW > capillary_cutoff) then
                             @:compute_capilary_stress_tensor()
@@ -245,7 +245,7 @@ contains
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    c_divs(1)%sf(j, k, l) = 1d0/(x_cc(j + 1) - x_cc(j - 1))* &
+                    c_divs(1)%sf(j, k, l) = 1._wp/(x_cc(j + 1) - x_cc(j - 1))* &
                                             (q_prim_vf(c_idx)%sf(j + 1, k, l) - q_prim_vf(c_idx)%sf(j - 1, k, l))
                 end do
             end do
@@ -255,7 +255,7 @@ contains
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    c_divs(2)%sf(j, k, l) = 1d0/(y_cc(k + 1) - y_cc(k - 1))* &
+                    c_divs(2)%sf(j, k, l) = 1._wp/(y_cc(k + 1) - y_cc(k - 1))* &
                                             (q_prim_vf(c_idx)%sf(j, k + 1, l) - q_prim_vf(c_idx)%sf(j, k - 1, l))
                 end do
             end do
@@ -266,7 +266,7 @@ contains
             do l = 0, p
                 do k = 0, n
                     do j = 0, m
-                        c_divs(3)%sf(j, k, l) = 1d0/(z_cc(l + 1) - z_cc(l - 1))* &
+                        c_divs(3)%sf(j, k, l) = 1._wp/(z_cc(l + 1) - z_cc(l - 1))* &
                                                 (q_prim_vf(c_idx)%sf(j, k, l + 1) - q_prim_vf(c_idx)%sf(j, k, l - 1))
                     end do
                 end do
@@ -277,12 +277,12 @@ contains
         do l = 0, p
             do k = 0, n
                 do j = 0, m
-                    c_divs(num_dims + 1)%sf(j, k, l) = 0d0
+                    c_divs(num_dims + 1)%sf(j, k, l) = 0._wp
                     !s$acc loop seq
                     do i = 1, num_dims
                         c_divs(num_dims + 1)%sf(j, k, l) = &
                             c_divs(num_dims + 1)%sf(j, k, l) + &
-                            c_divs(i)%sf(j, k, l)**2d0
+                            c_divs(i)%sf(j, k, l)**2._wp
                     end do
                     c_divs(num_dims + 1)%sf(j, k, l) = &
                         sqrt(c_divs(num_dims + 1)%sf(j, k, l))
@@ -306,8 +306,8 @@ contains
 
         type(scalar_field), dimension(iv%beg:iv%end), intent(in) :: v_vf
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, iv%beg:), intent(out) :: vL_x, vL_y, vL_z
-        real(kind(0d0)), dimension(startx:, starty:, startz:, iv%beg:), intent(out) :: vR_x, vR_y, vR_z
+        real(wp), dimension(startx:, starty:, startz:, iv%beg:), intent(out) :: vL_x, vL_y, vL_z
+        real(wp), dimension(startx:, starty:, startz:, iv%beg:), intent(out) :: vR_x, vR_y, vR_z
         integer, intent(in) :: norm_dir
 
         integer :: recon_dir !< Coordinate direction of the WENO reconstruction
diff --git a/src/simulation/m_time_steppers.fpp b/src/simulation/m_time_steppers.fpp
index b78a88439..15b08a3cb 100644
--- a/src/simulation/m_time_steppers.fpp
+++ b/src/simulation/m_time_steppers.fpp
@@ -17,7 +17,7 @@ module m_time_steppers
 
     use m_global_parameters    !< Definitions of the global parameters
 
-    use m_rhs                  !< Right-hand-side (RHS) evaluation procedures
+    use m_rhs                  !< Right-hane-side (RHS) evaluation procedures
 
     use m_data_output          !< Run-time info & solution data output procedures
 
@@ -56,11 +56,11 @@ module m_time_steppers
     type(vector_field), allocatable, dimension(:) :: q_prim_ts !<
     !! Cell-average primitive variables at consecutive TIMESTEPS
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :, :) :: rhs_pb
+    real(wp), allocatable, dimension(:, :, :, :, :) :: rhs_pb
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :, :) :: rhs_mv
+    real(wp), allocatable, dimension(:, :, :, :, :) :: rhs_mv
 
-    real(kind(0d0)), allocatable, dimension(:, :, :) :: max_dt
+    real(wp), allocatable, dimension(:, :, :) :: max_dt
 
     integer, private :: num_ts !<
     !! Number of time stages in the time-stepping scheme
@@ -274,7 +274,7 @@ contains
     subroutine s_1st_order_tvd_rk(t_step, time_avg)
 
         integer, intent(in) :: t_step
-        real(kind(0d0)), intent(inout) :: time_avg
+        real(wp), intent(inout) :: time_avg
 
         integer :: i, j, k, l, q !< Generic loop iterator
 
@@ -379,10 +379,10 @@ contains
     subroutine s_2nd_order_tvd_rk(t_step, time_avg)
 
         integer, intent(in) :: t_step
-        real(kind(0d0)), intent(inout) :: time_avg
+        real(wp), intent(inout) :: time_avg
 
         integer :: i, j, k, l, q!< Generic loop iterator
-        real(kind(0d0)) :: start, finish
+        real(wp) :: start, finish
 
         ! Stage 1 of 2 =====================================================
 
@@ -485,7 +485,7 @@ contains
                         q_cons_ts(1)%vf(i)%sf(j, k, l) = &
                             (q_cons_ts(1)%vf(i)%sf(j, k, l) &
                              + q_cons_ts(2)%vf(i)%sf(j, k, l) &
-                             + dt*rhs_vf(i)%sf(j, k, l))/2d0
+                             + dt*rhs_vf(i)%sf(j, k, l))/2._wp
                     end do
                 end do
             end do
@@ -501,7 +501,7 @@ contains
                                 pb_ts(1)%sf(j, k, l, q, i) = &
                                     (pb_ts(1)%sf(j, k, l, q, i) &
                                      + pb_ts(2)%sf(j, k, l, q, i) &
-                                     + dt*rhs_pb(j, k, l, q, i))/2d0
+                                     + dt*rhs_pb(j, k, l, q, i))/2._wp
                             end do
                         end do
                     end do
@@ -519,7 +519,7 @@ contains
                                 mv_ts(1)%sf(j, k, l, q, i) = &
                                     (mv_ts(1)%sf(j, k, l, q, i) &
                                      + mv_ts(2)%sf(j, k, l, q, i) &
-                                     + dt*rhs_mv(j, k, l, q, i))/2d0
+                                     + dt*rhs_mv(j, k, l, q, i))/2._wp
                             end do
                         end do
                     end do
@@ -527,7 +527,7 @@ contains
             end do
         end if
 
-        if (bodyForces) call s_apply_bodyforces(q_cons_ts(1)%vf, q_prim_vf, rhs_vf, 2d0*dt/3d0)
+        if (bodyForces) call s_apply_bodyforces(q_cons_ts(1)%vf, q_prim_vf, rhs_vf, 2._wp*dt/3._wp)
 
         if (grid_geometry == 3) call s_apply_fourier_filter(q_cons_ts(1)%vf)
 
@@ -557,10 +557,11 @@ contains
     subroutine s_3rd_order_tvd_rk(t_step, time_avg) ! --------------------------------
 
         integer, intent(IN) :: t_step
-        real(kind(0d0)), intent(INOUT) :: time_avg
+        real(wp), intent(INOUT) :: time_avg
 
         integer :: i, j, k, l, q !< Generic loop iterator
-        real(kind(0d0)) :: start, finish
+
+        real(wp) :: start, finish
 
         ! Stage 1 of 3 =====================================================
 
@@ -662,9 +663,9 @@ contains
                 do k = 0, n
                     do j = 0, m
                         q_cons_ts(2)%vf(i)%sf(j, k, l) = &
-                            (3d0*q_cons_ts(1)%vf(i)%sf(j, k, l) &
+                            (3._wp*q_cons_ts(1)%vf(i)%sf(j, k, l) &
                              + q_cons_ts(2)%vf(i)%sf(j, k, l) &
-                             + dt*rhs_vf(i)%sf(j, k, l))/4d0
+                             + dt*rhs_vf(i)%sf(j, k, l))/4._wp
                     end do
                 end do
             end do
@@ -678,9 +679,9 @@ contains
                         do j = 0, m
                             do q = 1, nnode
                                 pb_ts(2)%sf(j, k, l, q, i) = &
-                                    (3d0*pb_ts(1)%sf(j, k, l, q, i) &
+                                    (3._wp*pb_ts(1)%sf(j, k, l, q, i) &
                                      + pb_ts(2)%sf(j, k, l, q, i) &
-                                     + dt*rhs_pb(j, k, l, q, i))/4d0
+                                     + dt*rhs_pb(j, k, l, q, i))/4._wp
                             end do
                         end do
                     end do
@@ -696,9 +697,9 @@ contains
                         do j = 0, m
                             do q = 1, nnode
                                 mv_ts(2)%sf(j, k, l, q, i) = &
-                                    (3d0*mv_ts(1)%sf(j, k, l, q, i) &
+                                    (3._wp*mv_ts(1)%sf(j, k, l, q, i) &
                                      + mv_ts(2)%sf(j, k, l, q, i) &
-                                     + dt*rhs_mv(j, k, l, q, i))/4d0
+                                     + dt*rhs_mv(j, k, l, q, i))/4._wp
                             end do
                         end do
                     end do
@@ -706,7 +707,7 @@ contains
             end do
         end if
 
-        if (bodyForces) call s_apply_bodyforces(q_cons_ts(2)%vf, q_prim_vf, rhs_vf, dt/4d0)
+        if (bodyForces) call s_apply_bodyforces(q_cons_ts(2)%vf, q_prim_vf, rhs_vf, dt/4._wp)
 
         if (grid_geometry == 3) call s_apply_fourier_filter(q_cons_ts(2)%vf)
 
@@ -735,8 +736,8 @@ contains
                     do j = 0, m
                         q_cons_ts(1)%vf(i)%sf(j, k, l) = &
                             (q_cons_ts(1)%vf(i)%sf(j, k, l) &
-                             + 2d0*q_cons_ts(2)%vf(i)%sf(j, k, l) &
-                             + 2d0*dt*rhs_vf(i)%sf(j, k, l))/3d0
+                             + 2._wp*q_cons_ts(2)%vf(i)%sf(j, k, l) &
+                             + 2._wp*dt*rhs_vf(i)%sf(j, k, l))/3._wp
                     end do
                 end do
             end do
@@ -751,8 +752,8 @@ contains
                             do q = 1, nnode
                                 pb_ts(1)%sf(j, k, l, q, i) = &
                                     (pb_ts(1)%sf(j, k, l, q, i) &
-                                     + 2d0*pb_ts(2)%sf(j, k, l, q, i) &
-                                     + 2d0*dt*rhs_pb(j, k, l, q, i))/3d0
+                                     + 2._wp*pb_ts(2)%sf(j, k, l, q, i) &
+                                     + 2._wp*dt*rhs_pb(j, k, l, q, i))/3._wp
                             end do
                         end do
                     end do
@@ -769,8 +770,8 @@ contains
                             do q = 1, nnode
                                 mv_ts(1)%sf(j, k, l, q, i) = &
                                     (mv_ts(1)%sf(j, k, l, q, i) &
-                                     + 2d0*mv_ts(2)%sf(j, k, l, q, i) &
-                                     + 2d0*dt*rhs_mv(j, k, l, q, i))/3d0
+                                     + 2._wp*mv_ts(2)%sf(j, k, l, q, i) &
+                                     + 2._wp*dt*rhs_mv(j, k, l, q, i))/3._wp
                             end do
                         end do
                     end do
@@ -778,7 +779,7 @@ contains
             end do
         end if
 
-        if (bodyForces) call s_apply_bodyforces(q_cons_ts(1)%vf, q_prim_vf, rhs_vf, 2d0*dt/3d0)
+        if (bodyForces) call s_apply_bodyforces(q_cons_ts(1)%vf, q_prim_vf, rhs_vf, 2._wp*dt/3._wp)
 
         if (grid_geometry == 3) call s_apply_fourier_filter(q_cons_ts(1)%vf)
 
@@ -813,9 +814,9 @@ contains
     subroutine s_strang_splitting(t_step, time_avg)
 
         integer, intent(in) :: t_step
-        real(kind(0d0)), intent(inout) :: time_avg
+        real(wp), intent(inout) :: time_avg
 
-        real(kind(0d0)) :: start, finish
+        real(wp) :: start, finish
 
         call cpu_time(start)
 
@@ -862,18 +863,19 @@ contains
 
     subroutine s_compute_dt()
 
-        real(kind(0d0)) :: rho        !< Cell-avg. density
-        real(kind(0d0)), dimension(num_dims) :: vel        !< Cell-avg. velocity
-        real(kind(0d0)) :: vel_sum    !< Cell-avg. velocity sum
-        real(kind(0d0)) :: pres       !< Cell-avg. pressure
-        real(kind(0d0)), dimension(num_fluids) :: alpha      !< Cell-avg. volume fraction
-        real(kind(0d0)) :: gamma      !< Cell-avg. sp. heat ratio
-        real(kind(0d0)) :: pi_inf     !< Cell-avg. liquid stiffness function
-        real(kind(0d0)) :: c          !< Cell-avg. sound speed
-        real(kind(0d0)) :: H          !< Cell-avg. enthalpy
-        real(kind(0d0)), dimension(2) :: Re         !< Cell-avg. Reynolds numbers
+        real(wp) :: rho        !< Cell-avg. density
+        real(wp), dimension(num_dims) :: vel        !< Cell-avg. velocity
+        real(wp) :: vel_sum    !< Cell-avg. velocity sum
+        real(wp) :: pres       !< Cell-avg. pressure
+        real(wp), dimension(num_fluids) :: alpha      !< Cell-avg. volume fraction
+        real(wp) :: gamma      !< Cell-avg. sp. heat ratio
+        real(wp) :: pi_inf     !< Cell-avg. liquid stiffness function
+        real(wp) :: c          !< Cell-avg. sound speed
+        real(wp) :: H          !< Cell-avg. enthalpy
+        real(wp), dimension(2) :: Re         !< Cell-avg. Reynolds numbers
         type(vector_field) :: gm_alpha_qp
-        real(kind(0d0)) :: dt_local
+
+        real(wp) :: dt_local
         integer :: j, k, l !< Generic loop iterators
 
         call s_convert_conservative_to_primitive_variables( &
@@ -889,7 +891,7 @@ contains
                     call s_compute_enthalpy(q_prim_vf, pres, rho, gamma, pi_inf, Re, H, alpha, vel, vel_sum, j, k, l)
 
                     ! Compute mixture sound speed
-                    call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, H, alpha, vel_sum, 0d0, c)
+                    call s_compute_speed_of_sound(pres, rho, gamma, pi_inf, H, alpha, vel_sum, 0._wp, c)
 
                     call s_compute_dt_from_cfl(vel, c, max_dt, rho, Re, j, k, l)
                 end do
@@ -918,7 +920,7 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(in) :: q_prim_vf
         type(scalar_field), dimension(1:sys_size), intent(inout) :: rhs_vf
 
-        real(kind(0d0)), intent(in) :: ldt !< local dt
+        real(wp), intent(in) :: ldt !< local dt
 
         integer :: i, j, k, l
 
diff --git a/src/simulation/m_viscous.fpp b/src/simulation/m_viscous.fpp
index afe909ca5..a09c6384b 100644
--- a/src/simulation/m_viscous.fpp
+++ b/src/simulation/m_viscous.fpp
@@ -28,7 +28,7 @@ module m_viscous
     type(int_bounds_info) :: is1_viscous, is2_viscous, is3_viscous
     !$acc declare create(is1_viscous, is2_viscous, is3_viscous, iv)
 
-    real(kind(0d0)), allocatable, dimension(:, :) :: Res_viscous
+    real(wp), allocatable, dimension(:, :) :: Res_viscous
     !$acc declare create(Res_viscous)
 
 contains
@@ -67,11 +67,11 @@ contains
         type(scalar_field), dimension(1:sys_size), intent(inout) :: tau_Re_vf
         type(int_bounds_info), intent(in) :: ix, iy, iz
 
-        real(kind(0d0)) :: rho_visc, gamma_visc, pi_inf_visc, alpha_visc_sum  !< Mixture variables
-        real(kind(0d0)), dimension(2) :: Re_visc
-        real(kind(0d0)), dimension(num_fluids) :: alpha_visc, alpha_rho_visc
+        real(wp) :: rho_visc, gamma_visc, pi_inf_visc, alpha_visc_sum  !< Mixture variables
+        real(wp), dimension(2) :: Re_visc
+        real(wp), dimension(num_fluids) :: alpha_visc, alpha_rho_visc
 
-        real(kind(0d0)), dimension(num_dims, num_dims) :: tau_Re
+        real(wp), dimension(num_dims, num_dims) :: tau_Re
 
         integer :: i, j, k, l, q !< Generic loop iterator
 
@@ -85,7 +85,7 @@ contains
                 do j = is1_viscous%beg, is1_viscous%end
                     !$acc loop seq
                     do i = momxb, E_idx
-                        tau_Re_vf(i)%sf(j, k, l) = 0d0
+                        tau_Re_vf(i)%sf(j, k, l) = 0._wp
                     end do
                 end do
             end do
@@ -100,16 +100,16 @@ contains
                         do i = 1, num_fluids
                             alpha_rho_visc(i) = q_prim_vf(i)%sf(j, k, l)
                             if (bubbles .and. num_fluids == 1) then
-                                alpha_visc(i) = 1d0 - q_prim_vf(E_idx + i)%sf(j, k, l)
+                                alpha_visc(i) = 1._wp - q_prim_vf(E_idx + i)%sf(j, k, l)
                             else
                                 alpha_visc(i) = q_prim_vf(E_idx + i)%sf(j, k, l)
                             end if
                         end do
 
                         if (bubbles) then
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
                             if (mpp_lim .and. (model_eqns == 2) .and. (num_fluids > 2)) then
                                 !$acc loop seq
@@ -131,17 +131,17 @@ contains
                                 pi_inf_visc = pi_infs(1)
                             end if
                         else
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
-                            alpha_visc_sum = 0d0
+                            alpha_visc_sum = 0._wp
 
                             if (mpp_lim) then
                                 !$acc loop seq
                                 do i = 1, num_fluids
-                                    alpha_rho_visc(i) = max(0d0, alpha_rho_visc(i))
-                                    alpha_visc(i) = min(max(0d0, alpha_visc(i)), 1d0)
+                                    alpha_rho_visc(i) = max(0._wp, alpha_rho_visc(i))
+                                    alpha_visc(i) = min(max(0._wp, alpha_visc(i)), 1._wp)
                                     alpha_visc_sum = alpha_visc_sum + alpha_visc(i)
                                 end do
 
@@ -161,14 +161,14 @@ contains
                                 do i = 1, 2
                                     Re_visc(i) = dflt_real
 
-                                    if (Re_size(i) > 0) Re_visc(i) = 0d0
+                                    if (Re_size(i) > 0) Re_visc(i) = 0._wp
                                     !$acc loop seq
                                     do q = 1, Re_size(i)
                                         Re_visc(i) = alpha_visc(Re_idx(i, q))/Res_viscous(i, q) &
                                                      + Re_visc(i)
                                     end do
 
-                                    Re_visc(i) = 1d0/max(Re_visc(i), sgm_eps)
+                                    Re_visc(i) = 1._wp/max(Re_visc(i), sgm_eps)
 
                                 end do
                             end if
@@ -178,10 +178,10 @@ contains
                                         grad_x_vf(2)%sf(j, k, l))/ &
                                        Re_visc(1)
 
-                        tau_Re(2, 2) = (4d0*grad_y_vf(2)%sf(j, k, l) &
-                                        - 2d0*grad_x_vf(1)%sf(j, k, l) &
-                                        - 2d0*q_prim_vf(momxb + 1)%sf(j, k, l)/y_cc(k))/ &
-                                       (3d0*Re_visc(1))
+                        tau_Re(2, 2) = (4._wp*grad_y_vf(2)%sf(j, k, l) &
+                                        - 2._wp*grad_x_vf(1)%sf(j, k, l) &
+                                        - 2._wp*q_prim_vf(momxb + 1)%sf(j, k, l)/y_cc(k))/ &
+                                       (3._wp*Re_visc(1))
                         !$acc loop seq
                         do i = 1, 2
                             tau_Re_vf(contxe + i)%sf(j, k, l) = &
@@ -207,16 +207,16 @@ contains
                         do i = 1, num_fluids
                             alpha_rho_visc(i) = q_prim_vf(i)%sf(j, k, l)
                             if (bubbles .and. num_fluids == 1) then
-                                alpha_visc(i) = 1d0 - q_prim_vf(E_idx + i)%sf(j, k, l)
+                                alpha_visc(i) = 1._wp - q_prim_vf(E_idx + i)%sf(j, k, l)
                             else
                                 alpha_visc(i) = q_prim_vf(E_idx + i)%sf(j, k, l)
                             end if
                         end do
 
                         if (bubbles) then
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
                             if (mpp_lim .and. (model_eqns == 2) .and. (num_fluids > 2)) then
                                 !$acc loop seq
@@ -238,17 +238,17 @@ contains
                                 pi_inf_visc = pi_infs(1)
                             end if
                         else
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
-                            alpha_visc_sum = 0d0
+                            alpha_visc_sum = 0._wp
 
                             if (mpp_lim) then
                                 !$acc loop seq
                                 do i = 1, num_fluids
-                                    alpha_rho_visc(i) = max(0d0, alpha_rho_visc(i))
-                                    alpha_visc(i) = min(max(0d0, alpha_visc(i)), 1d0)
+                                    alpha_rho_visc(i) = max(0._wp, alpha_rho_visc(i))
+                                    alpha_visc(i) = min(max(0._wp, alpha_visc(i)), 1._wp)
                                     alpha_visc_sum = alpha_visc_sum + alpha_visc(i)
                                 end do
 
@@ -268,14 +268,14 @@ contains
                                 do i = 1, 2
                                     Re_visc(i) = dflt_real
 
-                                    if (Re_size(i) > 0) Re_visc(i) = 0d0
+                                    if (Re_size(i) > 0) Re_visc(i) = 0._wp
                                     !$acc loop seq
                                     do q = 1, Re_size(i)
                                         Re_visc(i) = alpha_visc(Re_idx(i, q))/Res_viscous(i, q) &
                                                      + Re_visc(i)
                                     end do
 
-                                    Re_visc(i) = 1d0/max(Re_visc(i), sgm_eps)
+                                    Re_visc(i) = 1._wp/max(Re_visc(i), sgm_eps)
 
                                 end do
                             end if
@@ -311,16 +311,16 @@ contains
                         do i = 1, num_fluids
                             alpha_rho_visc(i) = q_prim_vf(i)%sf(j, k, l)
                             if (bubbles .and. num_fluids == 1) then
-                                alpha_visc(i) = 1d0 - q_prim_vf(E_idx + i)%sf(j, k, l)
+                                alpha_visc(i) = 1._wp - q_prim_vf(E_idx + i)%sf(j, k, l)
                             else
                                 alpha_visc(i) = q_prim_vf(E_idx + i)%sf(j, k, l)
                             end if
                         end do
 
                         if (bubbles) then
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
                             if (mpp_lim .and. (model_eqns == 2) .and. (num_fluids > 2)) then
                                 !$acc loop seq
@@ -342,17 +342,17 @@ contains
                                 pi_inf_visc = pi_infs(1)
                             end if
                         else
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
-                            alpha_visc_sum = 0d0
+                            alpha_visc_sum = 0._wp
 
                             if (mpp_lim) then
                                 !$acc loop seq
                                 do i = 1, num_fluids
-                                    alpha_rho_visc(i) = max(0d0, alpha_rho_visc(i))
-                                    alpha_visc(i) = min(max(0d0, alpha_visc(i)), 1d0)
+                                    alpha_rho_visc(i) = max(0._wp, alpha_rho_visc(i))
+                                    alpha_visc(i) = min(max(0._wp, alpha_visc(i)), 1._wp)
                                     alpha_visc_sum = alpha_visc_sum + alpha_visc(i)
                                 end do
 
@@ -372,20 +372,20 @@ contains
                                 do i = 1, 2
                                     Re_visc(i) = dflt_real
 
-                                    if (Re_size(i) > 0) Re_visc(i) = 0d0
+                                    if (Re_size(i) > 0) Re_visc(i) = 0._wp
                                     !$acc loop seq
                                     do q = 1, Re_size(i)
                                         Re_visc(i) = alpha_visc(Re_idx(i, q))/Res_viscous(i, q) &
                                                      + Re_visc(i)
                                     end do
 
-                                    Re_visc(i) = 1d0/max(Re_visc(i), sgm_eps)
+                                    Re_visc(i) = 1._wp/max(Re_visc(i), sgm_eps)
 
                                 end do
                             end if
                         end if
 
-                        tau_Re(2, 2) = -(2d0/3d0)*grad_z_vf(3)%sf(j, k, l)/y_cc(k)/ &
+                        tau_Re(2, 2) = -(2._wp/3._wp)*grad_z_vf(3)%sf(j, k, l)/y_cc(k)/ &
                                        Re_visc(1)
 
                         tau_Re(2, 3) = ((grad_z_vf(2)%sf(j, k, l) - &
@@ -419,16 +419,16 @@ contains
                         do i = 1, num_fluids
                             alpha_rho_visc(i) = q_prim_vf(i)%sf(j, k, l)
                             if (bubbles .and. num_fluids == 1) then
-                                alpha_visc(i) = 1d0 - q_prim_vf(E_idx + i)%sf(j, k, l)
+                                alpha_visc(i) = 1._wp - q_prim_vf(E_idx + i)%sf(j, k, l)
                             else
                                 alpha_visc(i) = q_prim_vf(E_idx + i)%sf(j, k, l)
                             end if
                         end do
 
                         if (bubbles) then
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
                             if (mpp_lim .and. (model_eqns == 2) .and. (num_fluids > 2)) then
                                 !$acc loop seq
@@ -450,17 +450,17 @@ contains
                                 pi_inf_visc = pi_infs(1)
                             end if
                         else
-                            rho_visc = 0d0
-                            gamma_visc = 0d0
-                            pi_inf_visc = 0d0
+                            rho_visc = 0._wp
+                            gamma_visc = 0._wp
+                            pi_inf_visc = 0._wp
 
-                            alpha_visc_sum = 0d0
+                            alpha_visc_sum = 0._wp
 
                             if (mpp_lim) then
                                 !$acc loop seq
                                 do i = 1, num_fluids
-                                    alpha_rho_visc(i) = max(0d0, alpha_rho_visc(i))
-                                    alpha_visc(i) = min(max(0d0, alpha_visc(i)), 1d0)
+                                    alpha_rho_visc(i) = max(0._wp, alpha_rho_visc(i))
+                                    alpha_visc(i) = min(max(0._wp, alpha_visc(i)), 1._wp)
                                     alpha_visc_sum = alpha_visc_sum + alpha_visc(i)
                                 end do
 
@@ -480,14 +480,14 @@ contains
                                 do i = 1, 2
                                     Re_visc(i) = dflt_real
 
-                                    if (Re_size(i) > 0) Re_visc(i) = 0d0
+                                    if (Re_size(i) > 0) Re_visc(i) = 0._wp
                                     !$acc loop seq
                                     do q = 1, Re_size(i)
                                         Re_visc(i) = alpha_visc(Re_idx(i, q))/Res_viscous(i, q) &
                                                      + Re_visc(i)
                                     end do
 
-                                    Re_visc(i) = 1d0/max(Re_visc(i), sgm_eps)
+                                    Re_visc(i) = 1._wp/max(Re_visc(i), sgm_eps)
 
                                 end do
                             end if
@@ -524,7 +524,7 @@ contains
                              dq_prim_dx_qp, dq_prim_dy_qp, dq_prim_dz_qp, &
                              ix, iy, iz)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), &
+        real(wp), dimension(startx:, starty:, startz:, 1:), &
             intent(inout) :: qL_prim_rsx_vf, qR_prim_rsx_vf, &
                              qL_prim_rsy_vf, qR_prim_rsy_vf, &
                              qL_prim_rsz_vf, qR_prim_rsz_vf
@@ -665,7 +665,7 @@ contains
                                      dqL_prim_dx_n(1)%vf(i)%sf(k, j - 1, l) + &
                                      dqR_prim_dx_n(1)%vf(i)%sf(k, j - 1, l))
 
-                                dqL_prim_dx_n(2)%vf(i)%sf(k, j, l) = 25d-2* &
+                                dqL_prim_dx_n(2)%vf(i)%sf(k, j, l) = 25e-2_wp* &
                                                                      dqL_prim_dx_n(2)%vf(i)%sf(k, j, l)
                             end do
                         end do
@@ -684,7 +684,7 @@ contains
                                      dqL_prim_dx_n(1)%vf(i)%sf(k, j, l) + &
                                      dqR_prim_dx_n(1)%vf(i)%sf(k, j, l))
 
-                                dqR_prim_dx_n(2)%vf(i)%sf(k, j, l) = 25d-2* &
+                                dqR_prim_dx_n(2)%vf(i)%sf(k, j, l) = 25e-2_wp* &
                                                                      dqR_prim_dx_n(2)%vf(i)%sf(k, j, l)
 
                             end do
@@ -704,7 +704,7 @@ contains
                                      dqL_prim_dy_n(2)%vf(i)%sf(j - 1, k, l) + &
                                      dqR_prim_dy_n(2)%vf(i)%sf(j - 1, k, l))
 
-                                dqL_prim_dy_n(1)%vf(i)%sf(j, k, l) = 25d-2* &
+                                dqL_prim_dy_n(1)%vf(i)%sf(j, k, l) = 25e-2_wp* &
                                                                      dqL_prim_dy_n(1)%vf(i)%sf(j, k, l)
 
                             end do
@@ -724,7 +724,7 @@ contains
                                      dqL_prim_dy_n(2)%vf(i)%sf(j, k, l) + &
                                      dqR_prim_dy_n(2)%vf(i)%sf(j, k, l))
 
-                                dqR_prim_dy_n(1)%vf(i)%sf(j, k, l) = 25d-2* &
+                                dqR_prim_dy_n(1)%vf(i)%sf(j, k, l) = 25e-2_wp* &
                                                                      dqR_prim_dy_n(1)%vf(i)%sf(j, k, l)
 
                             end do
@@ -779,7 +779,7 @@ contains
                                          dqL_prim_dz_n(3)%vf(i)%sf(j - 1, k, l) + &
                                          dqR_prim_dz_n(3)%vf(i)%sf(j - 1, k, l))
 
-                                    dqL_prim_dz_n(1)%vf(i)%sf(j, k, l) = 25d-2* &
+                                    dqL_prim_dz_n(1)%vf(i)%sf(j, k, l) = 25e-2_wp* &
                                                                          dqL_prim_dz_n(1)%vf(i)%sf(j, k, l)
 
                                 end do
@@ -800,7 +800,7 @@ contains
                                          dqL_prim_dz_n(3)%vf(i)%sf(j, k, l) + &
                                          dqR_prim_dz_n(3)%vf(i)%sf(j, k, l))
 
-                                    dqR_prim_dz_n(1)%vf(i)%sf(j, k, l) = 25d-2* &
+                                    dqR_prim_dz_n(1)%vf(i)%sf(j, k, l) = 25e-2_wp* &
                                                                          dqR_prim_dz_n(1)%vf(i)%sf(j, k, l)
 
                                 end do
@@ -821,7 +821,7 @@ contains
                                          dqL_prim_dz_n(3)%vf(i)%sf(k, j - 1, l) + &
                                          dqR_prim_dz_n(3)%vf(i)%sf(k, j - 1, l))
 
-                                    dqL_prim_dz_n(2)%vf(i)%sf(k, j, l) = 25d-2* &
+                                    dqL_prim_dz_n(2)%vf(i)%sf(k, j, l) = 25e-2_wp* &
                                                                          dqL_prim_dz_n(2)%vf(i)%sf(k, j, l)
 
                                 end do
@@ -842,7 +842,7 @@ contains
                                          dqL_prim_dz_n(3)%vf(i)%sf(k, j, l) + &
                                          dqR_prim_dz_n(3)%vf(i)%sf(k, j, l))
 
-                                    dqR_prim_dz_n(2)%vf(i)%sf(k, j, l) = 25d-2* &
+                                    dqR_prim_dz_n(2)%vf(i)%sf(k, j, l) = 25e-2_wp* &
                                                                          dqR_prim_dz_n(2)%vf(i)%sf(k, j, l)
 
                                 end do
@@ -863,7 +863,7 @@ contains
                                          dqL_prim_dy_n(2)%vf(i)%sf(k, l, j - 1) + &
                                          dqR_prim_dy_n(2)%vf(i)%sf(k, l, j - 1))
 
-                                    dqL_prim_dy_n(3)%vf(i)%sf(k, l, j) = 25d-2* &
+                                    dqL_prim_dy_n(3)%vf(i)%sf(k, l, j) = 25e-2_wp* &
                                                                          dqL_prim_dy_n(3)%vf(i)%sf(k, l, j)
 
                                 end do
@@ -884,7 +884,7 @@ contains
                                          dqL_prim_dy_n(2)%vf(i)%sf(k, l, j) + &
                                          dqR_prim_dy_n(2)%vf(i)%sf(k, l, j))
 
-                                    dqR_prim_dy_n(3)%vf(i)%sf(k, l, j) = 25d-2* &
+                                    dqR_prim_dy_n(3)%vf(i)%sf(k, l, j) = 25e-2_wp* &
                                                                          dqR_prim_dy_n(3)%vf(i)%sf(k, l, j)
 
                                 end do
@@ -904,7 +904,7 @@ contains
                                          dqL_prim_dx_n(1)%vf(i)%sf(k, l, j - 1) + &
                                          dqR_prim_dx_n(1)%vf(i)%sf(k, l, j - 1))
 
-                                    dqL_prim_dx_n(3)%vf(i)%sf(k, l, j) = 25d-2* &
+                                    dqL_prim_dx_n(3)%vf(i)%sf(k, l, j) = 25e-2_wp* &
                                                                          dqL_prim_dx_n(3)%vf(i)%sf(k, l, j)
 
                                 end do
@@ -923,7 +923,7 @@ contains
                                          dqL_prim_dx_n(1)%vf(i)%sf(k, l, j) + &
                                          dqR_prim_dx_n(1)%vf(i)%sf(k, l, j))
 
-                                    dqR_prim_dx_n(3)%vf(i)%sf(k, l, j) = 25d-2* &
+                                    dqR_prim_dx_n(3)%vf(i)%sf(k, l, j) = 25e-2_wp* &
                                                                          dqR_prim_dx_n(3)%vf(i)%sf(k, l, j)
 
                                 end do
@@ -970,7 +970,7 @@ contains
         type(scalar_field), dimension(iv%beg:iv%end), intent(in) :: v_vf
         type(scalar_field), dimension(iv%beg:iv%end), intent(inout) :: vL_prim_vf, vR_prim_vf
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_x, vL_y, vL_z, vR_x, vR_y, vR_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_x, vL_y, vL_z, vR_x, vR_y, vR_z
         integer, intent(in) :: norm_dir
         type(int_bounds_info), intent(in) :: ix, iy, iz
 
@@ -1068,7 +1068,7 @@ contains
                                                              norm_dir, vL_prim_vf, vR_prim_vf, ix, iy, iz)
 
         type(scalar_field), dimension(iv%beg:iv%end), intent(in) :: v_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, iv%beg:), intent(inout) :: vL_x, vL_y, vL_z, vR_x, vR_y, vR_z
+        real(wp), dimension(startx:, starty:, startz:, iv%beg:), intent(inout) :: vL_x, vL_y, vL_z, vR_x, vR_y, vR_z
         type(scalar_field), dimension(iv%beg:iv%end), intent(inout) :: vL_prim_vf, vR_prim_vf
         type(int_bounds_info), intent(in) :: ix, iy, iz
 
@@ -1191,7 +1191,7 @@ contains
         integer, intent(in) :: norm_dir
         type(int_bounds_info), intent(in) :: ix, iy, iz, iv_in
         integer, intent(in) :: dim, buff_size_in
-        real(kind(0d0)), dimension(-buff_size_in:dim + buff_size_in), intent(in) :: dL
+        real(wp), dimension(-buff_size_in:dim + buff_size_in), intent(in) :: dL
 
         integer :: i, j, k, l !< Generic loop iterators
 
@@ -1218,7 +1218,7 @@ contains
                         !$acc loop seq
                         do i = iv%beg, iv%end
                             dv_ds_vf(i)%sf(j, k, l) = &
-                                1d0/((1d0 + wa_flg)*dL(j)) &
+                                1._wp/((1._wp + wa_flg)*dL(j)) &
                                 *(wa_flg*vL_vf(i)%sf(j + 1, k, l) &
                                   + vR_vf(i)%sf(j, k, l) &
                                   - vL_vf(i)%sf(j, k, l) &
@@ -1246,7 +1246,7 @@ contains
                         !$acc loop seq
                         do i = iv%beg, iv%end
                             dv_ds_vf(i)%sf(j, k, l) = &
-                                1d0/((1d0 + wa_flg)*dL(k)) &
+                                1._wp/((1._wp + wa_flg)*dL(k)) &
                                 *(wa_flg*vL_vf(i)%sf(j, k + 1, l) &
                                   + vR_vf(i)%sf(j, k, l) &
                                   - vL_vf(i)%sf(j, k, l) &
@@ -1274,7 +1274,7 @@ contains
                         !$acc loop seq
                         do i = iv%beg, iv%end
                             dv_ds_vf(i)%sf(j, k, l) = &
-                                1d0/((1d0 + wa_flg)*dL(l)) &
+                                1._wp/((1._wp + wa_flg)*dL(l)) &
                                 *(wa_flg*vL_vf(i)%sf(j, k, l + 1) &
                                   + vR_vf(i)%sf(j, k, l) &
                                   - vL_vf(i)%sf(j, k, l) &
@@ -1363,10 +1363,10 @@ contains
         do l = idwbuff(3)%beg, idwbuff(3)%end
             do k = idwbuff(2)%beg, idwbuff(2)%end
                 grad_x%sf(idwbuff(1)%beg, k, l) = &
-                    (-3d0*var%sf(idwbuff(1)%beg, k, l) + 4d0*var%sf(idwbuff(1)%beg + 1, k, l) - var%sf(idwbuff(1)%beg + 2, k, l))/ &
+                    (-3._wp*var%sf(idwbuff(1)%beg, k, l) + 4._wp*var%sf(idwbuff(1)%beg + 1, k, l) - var%sf(idwbuff(1)%beg + 2, k, l))/ &
                     (x_cc(idwbuff(1)%beg + 2) - x_cc(idwbuff(1)%beg))
                 grad_x%sf(idwbuff(1)%end, k, l) = &
-                    (+3d0*var%sf(idwbuff(1)%end, k, l) - 4d0*var%sf(idwbuff(1)%end - 1, k, l) + var%sf(idwbuff(1)%end - 2, k, l))/ &
+                    (+3._wp*var%sf(idwbuff(1)%end, k, l) - 4._wp*var%sf(idwbuff(1)%end - 1, k, l) + var%sf(idwbuff(1)%end - 2, k, l))/ &
                     (x_cc(idwbuff(1)%end) - x_cc(idwbuff(1)%end - 2))
             end do
         end do
@@ -1375,10 +1375,10 @@ contains
             do l = idwbuff(3)%beg, idwbuff(3)%end
                 do j = idwbuff(1)%beg, idwbuff(1)%end
                     grad_y%sf(j, idwbuff(2)%beg, l) = &
-                        (-3d0*var%sf(j, idwbuff(2)%beg, l) + 4d0*var%sf(j, idwbuff(2)%beg + 1, l) - var%sf(j, idwbuff(2)%beg + 2, l))/ &
+                        (-3._wp*var%sf(j, idwbuff(2)%beg, l) + 4._wp*var%sf(j, idwbuff(2)%beg + 1, l) - var%sf(j, idwbuff(2)%beg + 2, l))/ &
                         (y_cc(idwbuff(2)%beg + 2) - y_cc(idwbuff(2)%beg))
                     grad_y%sf(j, idwbuff(2)%end, l) = &
-                        (+3d0*var%sf(j, idwbuff(2)%end, l) - 4d0*var%sf(j, idwbuff(2)%end - 1, l) + var%sf(j, idwbuff(2)%end - 2, l))/ &
+                        (+3._wp*var%sf(j, idwbuff(2)%end, l) - 4._wp*var%sf(j, idwbuff(2)%end - 1, l) + var%sf(j, idwbuff(2)%end - 2, l))/ &
                         (y_cc(idwbuff(2)%end) - y_cc(idwbuff(2)%end - 2))
                 end do
             end do
@@ -1387,10 +1387,10 @@ contains
                 do k = idwbuff(2)%beg, idwbuff(2)%end
                     do j = idwbuff(1)%beg, idwbuff(1)%end
                         grad_z%sf(j, k, idwbuff(3)%beg) = &
-                            (-3d0*var%sf(j, k, idwbuff(3)%beg) + 4d0*var%sf(j, k, idwbuff(3)%beg + 1) - var%sf(j, k, idwbuff(3)%beg + 2))/ &
+                            (-3._wp*var%sf(j, k, idwbuff(3)%beg) + 4._wp*var%sf(j, k, idwbuff(3)%beg + 1) - var%sf(j, k, idwbuff(3)%beg + 2))/ &
                             (z_cc(idwbuff(3)%beg + 2) - z_cc(is3_viscous%beg))
                         grad_z%sf(j, k, idwbuff(3)%end) = &
-                            (+3d0*var%sf(j, k, idwbuff(3)%end) - 4d0*var%sf(j, k, idwbuff(3)%end - 1) + var%sf(j, k, idwbuff(3)%end - 2))/ &
+                            (+3._wp*var%sf(j, k, idwbuff(3)%end) - 4._wp*var%sf(j, k, idwbuff(3)%end - 1) + var%sf(j, k, idwbuff(3)%end - 2))/ &
                             (z_cc(idwbuff(3)%end) - z_cc(idwbuff(3)%end - 2))
                     end do
                 end do
@@ -1401,7 +1401,7 @@ contains
             !$acc parallel loop collapse(2) gang vector default(present)
             do l = idwbuff(3)%beg, idwbuff(3)%end
                 do k = idwbuff(2)%beg, idwbuff(2)%end
-                    grad_x%sf(0, k, l) = (-3d0*var%sf(0, k, l) + 4d0*var%sf(1, k, l) - var%sf(2, k, l))/ &
+                    grad_x%sf(0, k, l) = (-3._wp*var%sf(0, k, l) + 4._wp*var%sf(1, k, l) - var%sf(2, k, l))/ &
                                          (x_cc(2) - x_cc(0))
                 end do
             end do
@@ -1410,7 +1410,7 @@ contains
             !$acc parallel loop collapse(2) gang vector default(present)
             do l = idwbuff(3)%beg, idwbuff(3)%end
                 do k = idwbuff(2)%beg, idwbuff(2)%end
-                    grad_x%sf(m, k, l) = (3d0*var%sf(m, k, l) - 4d0*var%sf(m - 1, k, l) + var%sf(m - 2, k, l))/ &
+                    grad_x%sf(m, k, l) = (3._wp*var%sf(m, k, l) - 4._wp*var%sf(m - 1, k, l) + var%sf(m - 2, k, l))/ &
                                          (x_cc(m) - x_cc(m - 2))
                 end do
             end do
@@ -1420,7 +1420,7 @@ contains
                 !$acc parallel loop collapse(2) gang vector default(present)
                 do l = idwbuff(3)%beg, idwbuff(3)%end
                     do j = idwbuff(1)%beg, idwbuff(1)%end
-                        grad_y%sf(j, 0, l) = (-3d0*var%sf(j, 0, l) + 4d0*var%sf(j, 1, l) - var%sf(j, 2, l))/ &
+                        grad_y%sf(j, 0, l) = (-3._wp*var%sf(j, 0, l) + 4._wp*var%sf(j, 1, l) - var%sf(j, 2, l))/ &
                                              (y_cc(2) - y_cc(0))
                     end do
                 end do
@@ -1429,7 +1429,7 @@ contains
                 !$acc parallel loop collapse(2) gang vector default(present)
                 do l = idwbuff(3)%beg, idwbuff(3)%end
                     do j = idwbuff(1)%beg, idwbuff(1)%end
-                        grad_y%sf(j, n, l) = (3d0*var%sf(j, n, l) - 4d0*var%sf(j, n - 1, l) + var%sf(j, n - 2, l))/ &
+                        grad_y%sf(j, n, l) = (3._wp*var%sf(j, n, l) - 4._wp*var%sf(j, n - 1, l) + var%sf(j, n - 2, l))/ &
                                              (y_cc(n) - y_cc(n - 2))
                     end do
                 end do
@@ -1440,7 +1440,7 @@ contains
                     do k = idwbuff(2)%beg, idwbuff(2)%end
                         do j = idwbuff(1)%beg, idwbuff(1)%end
                             grad_z%sf(j, k, 0) = &
-                                (-3d0*var%sf(j, k, 0) + 4d0*var%sf(j, k, 1) - var%sf(j, k, 2))/ &
+                                (-3._wp*var%sf(j, k, 0) + 4._wp*var%sf(j, k, 1) - var%sf(j, k, 2))/ &
                                 (z_cc(2) - z_cc(0))
                         end do
                     end do
@@ -1450,7 +1450,7 @@ contains
                     do k = idwbuff(2)%beg, idwbuff(2)%end
                         do j = idwbuff(1)%beg, idwbuff(1)%end
                             grad_z%sf(j, k, p) = &
-                                (3d0*var%sf(j, k, p) - 4d0*var%sf(j, k, p - 1) + var%sf(j, k, p - 2))/ &
+                                (3._wp*var%sf(j, k, p) - 4._wp*var%sf(j, k, p - 1) + var%sf(j, k, p - 2))/ &
                                 (z_cc(p) - z_cc(p - 2))
                         end do
                     end do
diff --git a/src/simulation/m_weno.fpp b/src/simulation/m_weno.fpp
index 38f659a8e..28665db59 100644
--- a/src/simulation/m_weno.fpp
+++ b/src/simulation/m_weno.fpp
@@ -44,7 +44,7 @@ module m_weno
     !! stencils (WS) that are annexed to each position of a given scalar field.
     !> @{
 
-    real(kind(0d0)), allocatable, dimension(:, :, :, :) :: v_rs_ws_x, v_rs_ws_y, v_rs_ws_z
+    real(wp), allocatable, dimension(:, :, :, :) :: v_rs_ws_x, v_rs_ws_y, v_rs_ws_z
     !> @}
 
     ! WENO Coefficients ========================================================
@@ -55,16 +55,17 @@ module m_weno
     !! second dimension identifies the position of its coefficients and the last
     !! dimension denotes the cell-location in the relevant coordinate direction.
     !> @{
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: poly_coef_cbL_x
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: poly_coef_cbL_y
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: poly_coef_cbL_z
 
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: poly_coef_cbR_x
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: poly_coef_cbR_y
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: poly_coef_cbR_z
+    real(wp), target, allocatable, dimension(:, :, :) :: poly_coef_cbL_x
+    real(wp), target, allocatable, dimension(:, :, :) :: poly_coef_cbL_y
+    real(wp), target, allocatable, dimension(:, :, :) :: poly_coef_cbL_z
 
-    !    real(kind(0d0)), pointer, dimension(:, :, :) :: poly_coef_L => null()
-    !    real(kind(0d0)), pointer, dimension(:, :, :) :: poly_coef_R => null()
+    real(wp), target, allocatable, dimension(:, :, :) :: poly_coef_cbR_x
+    real(wp), target, allocatable, dimension(:, :, :) :: poly_coef_cbR_y
+    real(wp), target, allocatable, dimension(:, :, :) :: poly_coef_cbR_z
+
+    !    real(wp), pointer, dimension(:, :, :) :: poly_coef_L => null()
+    !    real(wp), pointer, dimension(:, :, :) :: poly_coef_R => null()
     !> @}
 
     !> @name The ideal weights at the left and the right cell-boundaries and at the
@@ -72,15 +73,16 @@ module m_weno
     !! that the first dimension of the array identifies the weight, while the
     !! last denotes the cell-location in the relevant coordinate direction.
     !> @{
-    real(kind(0d0)), target, allocatable, dimension(:, :) :: d_cbL_x
-    real(kind(0d0)), target, allocatable, dimension(:, :) :: d_cbL_y
-    real(kind(0d0)), target, allocatable, dimension(:, :) :: d_cbL_z
-
-    real(kind(0d0)), target, allocatable, dimension(:, :) :: d_cbR_x
-    real(kind(0d0)), target, allocatable, dimension(:, :) :: d_cbR_y
-    real(kind(0d0)), target, allocatable, dimension(:, :) :: d_cbR_z
-!    real(kind(0d0)), pointer, dimension(:, :) :: d_L => null()
-!    real(kind(0d0)), pointer, dimension(:, :) :: d_R => null()
+
+    real(wp), target, allocatable, dimension(:, :) :: d_cbL_x
+    real(wp), target, allocatable, dimension(:, :) :: d_cbL_y
+    real(wp), target, allocatable, dimension(:, :) :: d_cbL_z
+
+    real(wp), target, allocatable, dimension(:, :) :: d_cbR_x
+    real(wp), target, allocatable, dimension(:, :) :: d_cbR_y
+    real(wp), target, allocatable, dimension(:, :) :: d_cbR_z
+!    real(wp), pointer, dimension(:, :) :: d_L => null()
+!    real(wp), pointer, dimension(:, :) :: d_R => null()
     !> @}
 
     !> @name Smoothness indicator coefficients in the x-, y-, and z-directions. Note
@@ -88,10 +90,11 @@ module m_weno
     !! second identifies the position of its coefficients and the last denotes
     !! the cell-location in the relevant coordinate direction.
     !> @{
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: beta_coef_x
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: beta_coef_y
-    real(kind(0d0)), target, allocatable, dimension(:, :, :) :: beta_coef_z
-!    real(kind(0d0)), pointer, dimension(:, :, :) :: beta_coef => null()
+
+    real(wp), target, allocatable, dimension(:, :, :) :: beta_coef_x
+    real(wp), target, allocatable, dimension(:, :, :) :: beta_coef_y
+    real(wp), target, allocatable, dimension(:, :, :) :: beta_coef_z
+!    real(wp), pointer, dimension(:, :, :) :: beta_coef => null()
     !> @}
 
     ! END: WENO Coefficients ===================================================
@@ -107,7 +110,7 @@ module m_weno
     !
     !> @}
 
-    real(kind(0d0)) :: test
+    real(wp) :: test
     !$acc declare create(test)
 
     !$acc declare create( &
@@ -235,15 +238,15 @@ contains
         type(int_bounds_info), intent(in) :: is
         integer :: s
 
-        real(kind(0d0)), pointer, dimension(:) :: s_cb => null() !<
+        real(wp), pointer, dimension(:) :: s_cb => null() !<
             !! Cell-boundary locations in the s-direction
 
         type(int_bounds_info) :: bc_s !< Boundary conditions (BC) in the s-direction
 
         integer :: i !< Generic loop iterator
 
-        real(kind(0d0)) :: w(1:8) ! Intermediate var for ideal weights: s_cb across overall stencil
-        real(kind(0d0)) :: y(1:4) ! Intermediate var for poly & beta: diff(s_cb) across sub-stencil
+        real(wp) :: w(1:8) ! Intermediate var for ideal weights: s_cb across overall stencil
+        real(wp) :: y(1:4) ! Intermediate var for poly & beta: diff(s_cb) across sub-stencil
 
         ! Determining the number of cells, the cell-boundary locations and
         ! the boundary conditions in the coordinate direction selected for
@@ -275,13 +278,13 @@ contains
                         d_cbL_${XYZ}$ (0, i + 1) = (s_cb(i - 1) - s_cb(i))/ &
                                                    (s_cb(i - 1) - s_cb(i + 2))
 
-                        d_cbR_${XYZ}$ (1, i + 1) = 1d0 - d_cbR_${XYZ}$ (0, i + 1)
-                        d_cbL_${XYZ}$ (1, i + 1) = 1d0 - d_cbL_${XYZ}$ (0, i + 1)
+                        d_cbR_${XYZ}$ (1, i + 1) = 1._wp - d_cbR_${XYZ}$ (0, i + 1)
+                        d_cbL_${XYZ}$ (1, i + 1) = 1._wp - d_cbL_${XYZ}$ (0, i + 1)
 
-                        beta_coef_${XYZ}$ (i + 1, 0, 0) = 4d0*(s_cb(i) - s_cb(i + 1))**2d0/ &
-                                                          (s_cb(i) - s_cb(i + 2))**2d0
-                        beta_coef_${XYZ}$ (i + 1, 1, 0) = 4d0*(s_cb(i) - s_cb(i + 1))**2d0/ &
-                                                          (s_cb(i - 1) - s_cb(i + 1))**2d0
+                        beta_coef_${XYZ}$ (i + 1, 0, 0) = 4._wp*(s_cb(i) - s_cb(i + 1))**2._wp/ &
+                                                          (s_cb(i) - s_cb(i + 2))**2._wp
+                        beta_coef_${XYZ}$ (i + 1, 1, 0) = 4._wp*(s_cb(i) - s_cb(i + 1))**2._wp/ &
+                                                          (s_cb(i - 1) - s_cb(i + 1))**2._wp
 
                     end do
 
@@ -291,13 +294,13 @@ contains
                     ! the WENO reconstruction
                     if (null_weights) then
                         if (bc_s%beg == -4) then
-                            d_cbR_${XYZ}$ (1, 0) = 0d0; d_cbR_${XYZ}$ (0, 0) = 1d0
-                            d_cbL_${XYZ}$ (1, 0) = 0d0; d_cbL_${XYZ}$ (0, 0) = 1d0
+                            d_cbR_${XYZ}$ (1, 0) = 0._wp; d_cbR_${XYZ}$ (0, 0) = 1._wp
+                            d_cbL_${XYZ}$ (1, 0) = 0._wp; d_cbL_${XYZ}$ (0, 0) = 1._wp
                         end if
 
                         if (bc_s%end == -4) then
-                            d_cbR_${XYZ}$ (0, s) = 0d0; d_cbR_${XYZ}$ (1, s) = 1d0
-                            d_cbL_${XYZ}$ (0, s) = 0d0; d_cbL_${XYZ}$ (1, s) = 1d0
+                            d_cbR_${XYZ}$ (0, s) = 0._wp; d_cbR_${XYZ}$ (1, s) = 1._wp
+                            d_cbL_${XYZ}$ (0, s) = 0._wp; d_cbL_${XYZ}$ (1, s) = 1._wp
                         end if
                     end if
                     ! END: Computing WENO3 Coefficients ================================
@@ -362,72 +365,72 @@ contains
                             ((s_cb(i) - s_cb(i + 2))*(s_cb(i) - s_cb(i + 3)))/ &
                             ((s_cb(i - 2) - s_cb(i + 2))*(s_cb(i - 2) - s_cb(i + 3)))
 
-                        d_cbR_${XYZ}$ (1, i + 1) = 1d0 - d_cbR_${XYZ}$ (0, i + 1) - d_cbR_${XYZ}$ (2, i + 1)
-                        d_cbL_${XYZ}$ (1, i + 1) = 1d0 - d_cbL_${XYZ}$ (0, i + 1) - d_cbL_${XYZ}$ (2, i + 1)
+                        d_cbR_${XYZ}$ (1, i + 1) = 1._wp - d_cbR_${XYZ}$ (0, i + 1) - d_cbR_${XYZ}$ (2, i + 1)
+                        d_cbL_${XYZ}$ (1, i + 1) = 1._wp - d_cbL_${XYZ}$ (0, i + 1) - d_cbL_${XYZ}$ (2, i + 1)
 
                         beta_coef_${XYZ}$ (i + 1, 0, 0) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(10d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + (s_cb(i + 1) - s_cb(i))*(s_cb(i + 2) - &
-                                                                                                             s_cb(i + 1)) + (s_cb(i + 2) - s_cb(i + 1))**2d0)/((s_cb(i) - &
-                                                                                                                                                                s_cb(i + 3))**2d0*(s_cb(i + 1) - s_cb(i + 3))**2d0)
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(10._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + (s_cb(i + 1) - s_cb(i))*(s_cb(i + 2) - &
+                                                                                                                     s_cb(i + 1)) + (s_cb(i + 2) - s_cb(i + 1))**2._wp)/((s_cb(i) - &
+                                                                                                                                                                          s_cb(i + 3))**2._wp*(s_cb(i + 1) - s_cb(i + 3))**2._wp)
 
                         beta_coef_${XYZ}$ (i + 1, 0, 1) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(19d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 - (s_cb(i + 1) - s_cb(i))*(s_cb(i + 3) - &
-                                                                                                             s_cb(i + 1)) + 2d0*(s_cb(i + 2) - s_cb(i))*((s_cb(i + 2) - &
-                                                                                                                                                          s_cb(i)) + (s_cb(i + 3) - s_cb(i + 1))))/((s_cb(i) - &
-                                                                                                                                                                                                     s_cb(i + 2))*(s_cb(i) - s_cb(i + 3))**2d0*(s_cb(i + 3) - &
-                                                                                                                                                                                                                                                s_cb(i + 1)))
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(19._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp - (s_cb(i + 1) - s_cb(i))*(s_cb(i + 3) - &
+                                                                                                                     s_cb(i + 1)) + 2._wp*(s_cb(i + 2) - s_cb(i))*((s_cb(i + 2) - &
+                                                                                                                                                                    s_cb(i)) + (s_cb(i + 3) - s_cb(i + 1))))/((s_cb(i) - &
+                                                                                                                                                                                                               s_cb(i + 2))*(s_cb(i) - s_cb(i + 3))**2._wp*(s_cb(i + 3) - &
+                                                                                                                                                                                                                                                            s_cb(i + 1)))
 
                         beta_coef_${XYZ}$ (i + 1, 0, 2) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(10d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + (s_cb(i + 1) - s_cb(i))*((s_cb(i + 2) - &
-                                                                                                              s_cb(i)) + (s_cb(i + 3) - s_cb(i + 1))) + ((s_cb(i + 2) - &
-                                                                                                                                                          s_cb(i)) + (s_cb(i + 3) - s_cb(i + 1)))**2d0)/((s_cb(i) - &
-                                                                                                                                                                                                          s_cb(i + 2))**2d0*(s_cb(i) - s_cb(i + 3))**2d0)
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(10._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + (s_cb(i + 1) - s_cb(i))*((s_cb(i + 2) - &
+                                                                                                                      s_cb(i)) + (s_cb(i + 3) - s_cb(i + 1))) + ((s_cb(i + 2) - &
+                                                                                                                                                                  s_cb(i)) + (s_cb(i + 3) - s_cb(i + 1)))**2._wp)/((s_cb(i) - &
+                                                                                                                                                                                                                    s_cb(i + 2))**2._wp*(s_cb(i) - s_cb(i + 3))**2._wp)
 
                         beta_coef_${XYZ}$ (i + 1, 1, 0) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(10d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + (s_cb(i) - s_cb(i - 1))**2d0 + (s_cb(i) - &
-                                                                                                                    s_cb(i - 1))*(s_cb(i + 1) - s_cb(i)))/((s_cb(i - 1) - &
-                                                                                                                                                            s_cb(i + 2))**2d0*(s_cb(i) - s_cb(i + 2))**2d0)
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(10._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + (s_cb(i) - s_cb(i - 1))**2._wp + (s_cb(i) - &
+                                                                                                                              s_cb(i - 1))*(s_cb(i + 1) - s_cb(i)))/((s_cb(i - 1) - &
+                                                                                                                                                                      s_cb(i + 2))**2._wp*(s_cb(i) - s_cb(i + 2))**2._wp)
 
                         beta_coef_${XYZ}$ (i + 1, 1, 1) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*((s_cb(i) - &
-                                                               s_cb(i + 1))*((s_cb(i) - s_cb(i - 1)) + 20d0*(s_cb(i + 1) - &
-                                                                                                             s_cb(i))) + (2d0*(s_cb(i) - s_cb(i - 1)) + (s_cb(i + 1) - &
-                                                                                                                                                         s_cb(i)))*(s_cb(i + 2) - s_cb(i)))/((s_cb(i + 1) - &
-                                                                                                                                                                                              s_cb(i - 1))*(s_cb(i - 1) - s_cb(i + 2))**2d0*(s_cb(i + 2) - &
-                                                                                                                                                                                                                                             s_cb(i)))
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*((s_cb(i) - &
+                                                                   s_cb(i + 1))*((s_cb(i) - s_cb(i - 1)) + 20._wp*(s_cb(i + 1) - &
+                                                                                                                   s_cb(i))) + (2._wp*(s_cb(i) - s_cb(i - 1)) + (s_cb(i + 1) - &
+                                                                                                                                                                 s_cb(i)))*(s_cb(i + 2) - s_cb(i)))/((s_cb(i + 1) - &
+                                                                                                                                                                                                      s_cb(i - 1))*(s_cb(i - 1) - s_cb(i + 2))**2._wp*(s_cb(i + 2) - &
+                                                                                                                                                                                                                                                       s_cb(i)))
 
                         beta_coef_${XYZ}$ (i + 1, 1, 2) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(10d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + (s_cb(i + 1) - s_cb(i))*(s_cb(i + 2) - &
-                                                                                                             s_cb(i + 1)) + (s_cb(i + 2) - s_cb(i + 1))**2d0)/ &
-                            ((s_cb(i - 1) - s_cb(i + 1))**2d0*(s_cb(i - 1) - &
-                                                               s_cb(i + 2))**2d0)
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(10._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + (s_cb(i + 1) - s_cb(i))*(s_cb(i + 2) - &
+                                                                                                                     s_cb(i + 1)) + (s_cb(i + 2) - s_cb(i + 1))**2._wp)/ &
+                            ((s_cb(i - 1) - s_cb(i + 1))**2._wp*(s_cb(i - 1) - &
+                                                                 s_cb(i + 2))**2._wp)
 
                         beta_coef_${XYZ}$ (i + 1, 2, 0) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(12d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + ((s_cb(i) - s_cb(i - 2)) + (s_cb(i) - &
-                                                                                                                s_cb(i - 1)))**2d0 + 3d0*((s_cb(i) - s_cb(i - 2)) + &
-                                                                                                                                          (s_cb(i) - s_cb(i - 1)))*(s_cb(i + 1) - s_cb(i)))/ &
-                            ((s_cb(i - 2) - s_cb(i + 1))**2d0*(s_cb(i - 1) - &
-                                                               s_cb(i + 1))**2d0)
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(12._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + ((s_cb(i) - s_cb(i - 2)) + (s_cb(i) - &
+                                                                                                                        s_cb(i - 1)))**2._wp + 3._wp*((s_cb(i) - s_cb(i - 2)) + &
+                                                                                                                                                      (s_cb(i) - s_cb(i - 1)))*(s_cb(i + 1) - s_cb(i)))/ &
+                            ((s_cb(i - 2) - s_cb(i + 1))**2._wp*(s_cb(i - 1) - &
+                                                                 s_cb(i + 1))**2._wp)
 
                         beta_coef_${XYZ}$ (i + 1, 2, 1) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(19d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + ((s_cb(i) - s_cb(i - 2))*(s_cb(i) - &
-                                                                                                              s_cb(i + 1))) + 2d0*(s_cb(i + 1) - s_cb(i - 1))*((s_cb(i) - &
-                                                                                                                                                                s_cb(i - 2)) + (s_cb(i + 1) - s_cb(i - 1))))/((s_cb(i - 2) - &
-                                                                                                                                                                                                               s_cb(i))*(s_cb(i - 2) - s_cb(i + 1))**2d0*(s_cb(i + 1) - &
-                                                                                                                                                                                                                                                          s_cb(i - 1)))
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(19._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + ((s_cb(i) - s_cb(i - 2))*(s_cb(i) - &
+                                                                                                                      s_cb(i + 1))) + 2._wp*(s_cb(i + 1) - s_cb(i - 1))*((s_cb(i) - &
+                                                                                                                                                                          s_cb(i - 2)) + (s_cb(i + 1) - s_cb(i - 1))))/((s_cb(i - 2) - &
+                                                                                                                                                                                                                         s_cb(i))*(s_cb(i - 2) - s_cb(i + 1))**2._wp*(s_cb(i + 1) - &
+                                                                                                                                                                                                                                                                      s_cb(i - 1)))
 
                         beta_coef_${XYZ}$ (i + 1, 2, 2) = &
-                            4d0*(s_cb(i) - s_cb(i + 1))**2d0*(10d0*(s_cb(i + 1) - &
-                                                                    s_cb(i))**2d0 + (s_cb(i) - s_cb(i - 1))**2d0 + (s_cb(i) - &
-                                                                                                                    s_cb(i - 1))*(s_cb(i + 1) - s_cb(i)))/((s_cb(i - 2) - &
-                                                                                                                                                            s_cb(i))**2d0*(s_cb(i - 2) - s_cb(i + 1))**2d0)
+                            4._wp*(s_cb(i) - s_cb(i + 1))**2._wp*(10._wp*(s_cb(i + 1) - &
+                                                                          s_cb(i))**2._wp + (s_cb(i) - s_cb(i - 1))**2._wp + (s_cb(i) - &
+                                                                                                                              s_cb(i - 1))*(s_cb(i + 1) - s_cb(i)))/((s_cb(i - 2) - &
+                                                                                                                                                                      s_cb(i))**2._wp*(s_cb(i - 2) - s_cb(i + 1))**2._wp)
 
                     end do
 
@@ -437,17 +440,17 @@ contains
                     ! the WENO reconstruction
                     if (null_weights) then
                         if (bc_s%beg == -4) then
-                            d_cbR_${XYZ}$ (1:2, 0) = 0d0; d_cbR_${XYZ}$ (0, 0) = 1d0
-                            d_cbL_${XYZ}$ (1:2, 0) = 0d0; d_cbL_${XYZ}$ (0, 0) = 1d0
-                            d_cbR_${XYZ}$ (2, 1) = 0d0; d_cbR_${XYZ}$ (:, 1) = d_cbR_${XYZ}$ (:, 1)/sum(d_cbR_${XYZ}$ (:, 1))
-                            d_cbL_${XYZ}$ (2, 1) = 0d0; d_cbL_${XYZ}$ (:, 1) = d_cbL_${XYZ}$ (:, 1)/sum(d_cbL_${XYZ}$ (:, 1))
+                            d_cbR_${XYZ}$ (1:2, 0) = 0._wp; d_cbR_${XYZ}$ (0, 0) = 1._wp
+                            d_cbL_${XYZ}$ (1:2, 0) = 0._wp; d_cbL_${XYZ}$ (0, 0) = 1._wp
+                            d_cbR_${XYZ}$ (2, 1) = 0._wp; d_cbR_${XYZ}$ (:, 1) = d_cbR_${XYZ}$ (:, 1)/sum(d_cbR_${XYZ}$ (:, 1))
+                            d_cbL_${XYZ}$ (2, 1) = 0._wp; d_cbL_${XYZ}$ (:, 1) = d_cbL_${XYZ}$ (:, 1)/sum(d_cbL_${XYZ}$ (:, 1))
                         end if
 
                         if (bc_s%end == -4) then
-                            d_cbR_${XYZ}$ (0, s - 1) = 0d0; d_cbR_${XYZ}$ (:, s - 1) = d_cbR_${XYZ}$ (:, s - 1)/sum(d_cbR_${XYZ}$ (:, s - 1))
-                            d_cbL_${XYZ}$ (0, s - 1) = 0d0; d_cbL_${XYZ}$ (:, s - 1) = d_cbL_${XYZ}$ (:, s - 1)/sum(d_cbL_${XYZ}$ (:, s - 1))
-                            d_cbR_${XYZ}$ (0:1, s) = 0d0; d_cbR_${XYZ}$ (2, s) = 1d0
-                            d_cbL_${XYZ}$ (0:1, s) = 0d0; d_cbL_${XYZ}$ (2, s) = 1d0
+                            d_cbR_${XYZ}$ (0, s - 1) = 0._wp; d_cbR_${XYZ}$ (:, s - 1) = d_cbR_${XYZ}$ (:, s - 1)/sum(d_cbR_${XYZ}$ (:, s - 1))
+                            d_cbL_${XYZ}$ (0, s - 1) = 0._wp; d_cbL_${XYZ}$ (:, s - 1) = d_cbL_${XYZ}$ (:, s - 1)/sum(d_cbL_${XYZ}$ (:, s - 1))
+                            d_cbR_${XYZ}$ (0:1, s) = 0._wp; d_cbR_${XYZ}$ (2, s) = 1._wp
+                            d_cbL_${XYZ}$ (0:1, s) = 0._wp; d_cbL_${XYZ}$ (2, s) = 1._wp
                         end if
                     end if
 
@@ -624,17 +627,17 @@ contains
 
                     else ! TENO (only supports uniform grid)
                         ! (Fu, et al., 2016) Table 2 (for right flux)
-                        d_cbL_${XYZ}$ (0, :) = 18d0/35d0
-                        d_cbL_${XYZ}$ (1, :) = 3d0/35d0
-                        d_cbL_${XYZ}$ (2, :) = 9d0/35d0
-                        d_cbL_${XYZ}$ (3, :) = 1d0/35d0
-                        d_cbL_${XYZ}$ (4, :) = 4d0/35d0
-
-                        d_cbR_${XYZ}$ (0, :) = 18d0/35d0
-                        d_cbR_${XYZ}$ (1, :) = 9d0/35d0
-                        d_cbR_${XYZ}$ (2, :) = 3d0/35d0
-                        d_cbR_${XYZ}$ (3, :) = 4d0/35d0
-                        d_cbR_${XYZ}$ (4, :) = 1d0/35d0
+                        d_cbL_${XYZ}$ (0, :) = 18._wp/35._wp
+                        d_cbL_${XYZ}$ (1, :) = 3._wp/35._wp
+                        d_cbL_${XYZ}$ (2, :) = 9._wp/35._wp
+                        d_cbL_${XYZ}$ (3, :) = 1._wp/35._wp
+                        d_cbL_${XYZ}$ (4, :) = 4._wp/35._wp
+
+                        d_cbR_${XYZ}$ (0, :) = 18._wp/35._wp
+                        d_cbR_${XYZ}$ (1, :) = 9._wp/35._wp
+                        d_cbR_${XYZ}$ (2, :) = 3._wp/35._wp
+                        d_cbR_${XYZ}$ (3, :) = 4._wp/35._wp
+                        d_cbR_${XYZ}$ (4, :) = 1._wp/35._wp
 
                     end if
                 end if
@@ -662,20 +665,20 @@ contains
                       is1_weno_d, is2_weno_d, is3_weno_d)
 
         type(scalar_field), dimension(1:), intent(in) :: v_vf
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_rs_vf_x, vL_rs_vf_y, vL_rs_vf_z
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vR_rs_vf_x, vR_rs_vf_y, vR_rs_vf_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vL_rs_vf_x, vL_rs_vf_y, vL_rs_vf_z
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(inout) :: vR_rs_vf_x, vR_rs_vf_y, vR_rs_vf_z
         integer, intent(in) :: norm_dir
         integer, intent(in) :: weno_dir
         type(int_bounds_info), intent(in) :: is1_weno_d, is2_weno_d, is3_weno_d
 
-        real(kind(0d0)), dimension(-weno_polyn:weno_polyn - 1) :: dvd
-        real(kind(0d0)), dimension(0:weno_num_stencils) :: poly
-        real(kind(0d0)), dimension(0:weno_num_stencils) :: alpha
-        real(kind(0d0)), dimension(0:weno_num_stencils) :: omega
-        real(kind(0d0)), dimension(0:weno_num_stencils) :: beta
-        real(kind(0d0)), dimension(0:weno_num_stencils) :: delta
-        real(kind(0d0)), dimension(-3:3) :: v ! temporary field value array for clarity (WENO7 only)
-        real(kind(0d0)) :: tau
+        real(wp), dimension(-weno_polyn:weno_polyn - 1) :: dvd
+        real(wp), dimension(0:weno_num_stencils) :: poly
+        real(wp), dimension(0:weno_num_stencils) :: alpha
+        real(wp), dimension(0:weno_num_stencils) :: omega
+        real(wp), dimension(0:weno_num_stencils) :: beta
+        real(wp), dimension(0:weno_num_stencils) :: delta
+        real(wp), dimension(-3:3) :: v ! temporary field value array for clarity (WENO7 only)
+        real(wp) :: tau
 
         integer :: i, j, k, l
 
@@ -762,13 +765,14 @@ contains
                                     elseif (mapped_weno) then
                                         alpha = d_cbL_${XYZ}$ (:, j)/(beta*beta)
                                         omega = alpha/sum(alpha)
-                                        alpha = (d_cbL_${XYZ}$ (:, j)*(1d0 + d_cbL_${XYZ}$ (:, j) - 3d0*omega) + omega**2d0) &
-                                                *(omega/(d_cbL_${XYZ}$ (:, j)**2d0 + omega*(1d0 - 2d0*d_cbL_${XYZ}$ (:, j))))
+                                        alpha = (d_cbL_${XYZ}$ (:, j)*(1._wp + d_cbL_${XYZ}$ (:, j) - 3._wp*omega) + omega**2._wp) &
+                                                *(omega/(d_cbL_${XYZ}$ (:, j)**2._wp + omega*(1._wp - 2._wp*d_cbL_${XYZ}$ (:, j))))
 
                                     elseif (wenoz) then
                                         ! Borges, et al. (2008)
+
                                         tau = abs(beta(1) - beta(0))
-                                        alpha = d_cbL_${XYZ}$ (:, j)*(1d0 + tau/beta)
+                                        alpha = d_cbL_${XYZ}$ (:, j)*(1._wp + tau/beta)
 
                                     end if
 
@@ -789,11 +793,12 @@ contains
                                     elseif (mapped_weno) then
                                         alpha = d_cbR_${XYZ}$ (:, j)/(beta*beta)
                                         omega = alpha/sum(alpha)
-                                        alpha = (d_cbR_${XYZ}$ (:, j)*(1d0 + d_cbR_${XYZ}$ (:, j) - 3d0*omega) + omega**2d0) &
-                                                *(omega/(d_cbR_${XYZ}$ (:, j)**2d0 + omega*(1d0 - 2d0*d_cbR_${XYZ}$ (:, j))))
+                                        alpha = (d_cbR_${XYZ}$ (:, j)*(1._wp + d_cbR_${XYZ}$ (:, j) - 3._wp*omega) + omega**2._wp) &
+                                                *(omega/(d_cbR_${XYZ}$ (:, j)**2._wp + omega*(1._wp - 2._wp*d_cbR_${XYZ}$ (:, j))))
 
                                     elseif (wenoz) then
-                                        alpha = d_cbR_${XYZ}$ (:, j)*(1d0 + tau/beta)
+
+                                        alpha = d_cbR_${XYZ}$ (:, j)*(1._wp + tau/beta)
 
                                     end if
 
@@ -857,21 +862,22 @@ contains
                                     elseif (mapped_weno) then
                                         alpha = d_cbL_${XYZ}$ (:, j)/(beta*beta)
                                         omega = alpha/sum(alpha)
-                                        alpha = (d_cbL_${XYZ}$ (:, j)*(1d0 + d_cbL_${XYZ}$ (:, j) - 3d0*omega) + omega**2d0) &
-                                                *(omega/(d_cbL_${XYZ}$ (:, j)**2d0 + omega*(1d0 - 2d0*d_cbL_${XYZ}$ (:, j))))
+                                        alpha = (d_cbL_${XYZ}$ (:, j)*(1._wp + d_cbL_${XYZ}$ (:, j) - 3._wp*omega) + omega**2._wp) &
+                                                *(omega/(d_cbL_${XYZ}$ (:, j)**2._wp + omega*(1._wp - 2._wp*d_cbL_${XYZ}$ (:, j))))
 
                                     elseif (wenoz) then
                                         ! Borges, et al. (2008)
+
                                         tau = abs(beta(2) - beta(0))                   ! Equation 25
-                                        alpha = d_cbL_${XYZ}$ (:, j)*(1d0 + tau/beta)  ! Equation 28 (note: weno_eps was already added to beta)
+                                        alpha = d_cbL_${XYZ}$ (:, j)*(1._wp + tau/beta)  ! Equation 28 (note: weno_eps was already added to beta)
 
                                     elseif (teno) then
                                         ! Fu, et al. (2016)
                                         ! Fu''s code: https://dx.doi.org/10.13140/RG.2.2.36250.34247
                                         tau = abs(beta(2) - beta(0))
-                                        alpha = (1d0 + tau/beta)**6d0              ! Equation 22 (reuse alpha as gamma; pick C=1 & q=6)
+                                        alpha = (1._wp + tau/beta)**6._wp           ! Equation 22 (reuse alpha as gamma; pick C=1 & q=6)
                                         omega = alpha/sum(alpha)                    ! Equation 25 (reuse omega as xi)
-                                        delta = merge(0d0, 1d0, omega < teno_CT)    ! Equation 26
+                                        delta = merge(0._wp, 1._wp, omega < teno_CT)    ! Equation 26
                                         alpha = delta*d_cbL_${XYZ}$ (:, j)          ! Equation 27
 
                                     end if
@@ -898,11 +904,12 @@ contains
                                     elseif (mapped_weno) then
                                         alpha = d_cbR_${XYZ}$ (:, j)/(beta*beta)
                                         omega = alpha/sum(alpha)
-                                        alpha = (d_cbR_${XYZ}$ (:, j)*(1d0 + d_cbR_${XYZ}$ (:, j) - 3d0*omega) + omega**2d0) &
-                                                *(omega/(d_cbR_${XYZ}$ (:, j)**2d0 + omega*(1d0 - 2d0*d_cbR_${XYZ}$ (:, j))))
+                                        alpha = (d_cbR_${XYZ}$ (:, j)*(1._wp + d_cbR_${XYZ}$ (:, j) - 3._wp*omega) + omega**2._wp) &
+                                                *(omega/(d_cbR_${XYZ}$ (:, j)**2._wp + omega*(1._wp - 2._wp*d_cbR_${XYZ}$ (:, j))))
 
                                     elseif (wenoz) then
-                                        alpha = d_cbR_${XYZ}$ (:, j)*(1d0 + tau/beta)
+
+                                        alpha = d_cbR_${XYZ}$ (:, j)*(1._wp + tau/beta)
 
                                     elseif (teno) then
                                         alpha = delta*d_cbR_${XYZ}$ (:, j)
@@ -974,14 +981,15 @@ contains
                                         ! See Figure 2 (right) for right-sided flux (at i+1/2)
                                         ! Here we need the left-sided flux, so we flip the weights with respect to the x=i point
                                         ! But we need to keep the stencil order to reuse the beta coefficients
-                                        poly(0) = ( 2d0*v(-1) +  5d0*v( 0) -  1d0*v( 1)) / 6d0 !&
-                                        poly(1) = (11d0*v( 0) -  7d0*v( 1) +  2d0*v( 2)) / 6d0 !&
-                                        poly(2) = (-1d0*v(-2) +  5d0*v(-1) +  2d0*v( 0)) / 6d0 !&
-                                        poly(3) = (25d0*v( 0) - 23d0*v( 1) + 13d0*v( 2) - 3d0*v( 3)) / 12d0 !&
-                                        poly(4) = ( 1d0*v(-3) -  5d0*v(-2) + 13d0*v(-1) + 3d0*v( 0)) / 12d0 !&
+                                        poly(0) = ( 2._wp*v(-1) +  5._wp*v( 0) -  1._wp*v( 1)) / 6._wp !&
+                                        poly(1) = (11._wp*v( 0) -  7._wp*v( 1) +  2._wp*v( 2)) / 6._wp !&
+                                        poly(2) = (-1._wp*v(-2) +  5._wp*v(-1) +  2._wp*v( 0)) / 6._wp !&
+                                        poly(3) = (25._wp*v( 0) - 23._wp*v( 1) + 13._wp*v( 2) - 3._wp*v( 3)) / 12._wp !&
+                                        poly(4) = ( 1._wp*v(-3) -  5._wp*v(-2) + 13._wp*v(-1) + 3._wp*v( 0)) / 12._wp !&
                                     end if
 
                                     if (.not. teno) then
+
                                         beta(3) = beta_coef_${XYZ}$ (j, 0, 0)*dvd(2)*dvd(2) &
                                                   + beta_coef_${XYZ}$ (j, 0, 1)*dvd(2)*dvd(1) &
                                                   + beta_coef_${XYZ}$ (j, 0, 2)*dvd(2)*dvd(0) &
@@ -1016,20 +1024,20 @@ contains
 
                                     else ! TENO
                                         ! High-Order Low-Dissipation Targeted ENO Schemes for Ideal Magnetohydrodynamics (Fu & Tang, 2019) Section 3.2
-                                        beta(0) = 13d0/12d0*(v(-1) - 2d0*v( 0) + v( 1))**2d0 + ((    v(-1)             -     v( 1))**2d0)/4d0 + weno_eps !&
-                                        beta(1) = 13d0/12d0*(v( 0) - 2d0*v( 1) + v( 2))**2d0 + ((3d0*v( 0) - 4d0*v( 1) +     v( 2))**2d0)/4d0 + weno_eps !&
-                                        beta(2) = 13d0/12d0*(v(-2) - 2d0*v(-1) + v( 0))**2d0 + ((    v(-2) - 4d0*v(-1) + 3d0*v( 0))**2d0)/4d0 + weno_eps !&
-
-                                        beta(3) = ( v( 0)*(2107d0*v( 0) - 9402d0*v( 1) +  7042d0*v( 2) - 1854d0*v( 3)) & !&
-                                                  + v( 1)*(              11003d0*v( 1) - 17246d0*v( 2) + 4642d0*v( 3)) & !&
-                                                  + v( 2)*(                               7043d0*v( 2) - 3882d0*v( 3)) & !&
-                                                  + v( 3)*(                                               547d0*v( 3)) ) / 240d0 & !&
+                                        beta(0) = 13._wp/12._wp*(v(-1) - 2._wp*v( 0) + v( 1))**2._wp + ((    v(-1)             -     v( 1))**2._wp)/4._wp + weno_eps !&
+                                        beta(1) = 13._wp/12._wp*(v( 0) - 2._wp*v( 1) + v( 2))**2._wp + ((3._wp*v( 0) - 4._wp*v( 1) +     v( 2))**2._wp)/4._wp + weno_eps !&
+                                        beta(2) = 13._wp/12._wp*(v(-2) - 2._wp*v(-1) + v( 0))**2._wp + ((    v(-2) - 4._wp*v(-1) + 3._wp*v( 0))**2._wp)/4._wp + weno_eps !&
+
+                                        beta(3) = ( v( 0)*(2107._wp*v( 0) - 9402._wp*v( 1) +  7042._wp*v( 2) - 1854._wp*v( 3)) & !&
+                                                  + v( 1)*(              11003._wp*v( 1) - 17246._wp*v( 2) + 4642._wp*v( 3)) & !&
+                                                  + v( 2)*(                               7043._wp*v( 2) - 3882._wp*v( 3)) & !&
+                                                  + v( 3)*(                                               547._wp*v( 3)) ) / 240._wp & !&
                                                   + weno_eps !&
 
-                                        beta(4) = ( v(-3)*(547d0*v(-3) - 3882d0*v(-2) +  4642d0*v(-1) - 1854d0*v( 0)) & !&
-                                                  + v(-2)*(              7043d0*v(-2) - 17246d0*v(-1) + 7042d0*v( 0)) & !&
-                                                  + v(-1)*(                             11003d0*v(-1) - 9402d0*v( 0)) & !&
-                                                  + v( 0)*(                                             2107d0*v( 0)) ) / 240d0 & !&
+                                        beta(4) = ( v(-3)*(547._wp*v(-3) - 3882._wp*v(-2) +  4642._wp*v(-1) - 1854._wp*v( 0)) & !&
+                                                  + v(-2)*(              7043._wp*v(-2) - 17246._wp*v(-1) + 7042._wp*v( 0)) & !&
+                                                  + v(-1)*(                             11003._wp*v(-1) - 9402._wp*v( 0)) & !&
+                                                  + v( 0)*(                                             2107._wp*v( 0)) ) / 240._wp & !&
                                                   + weno_eps !&
                                     end if
 
@@ -1039,20 +1047,20 @@ contains
                                     elseif (mapped_weno) then
                                         alpha = d_cbL_${XYZ}$ (:, j)/(beta*beta)
                                         omega = alpha/sum(alpha)
-                                        alpha = (d_cbL_${XYZ}$ (:, j)*(1d0 + d_cbL_${XYZ}$ (:, j) - 3d0*omega) + omega**2d0) &
-                                                *(omega/(d_cbL_${XYZ}$ (:, j)**2d0 + omega*(1d0 - 2d0*d_cbL_${XYZ}$ (:, j))))
+                                        alpha = (d_cbL_${XYZ}$ (:, j)*(1._wp + d_cbL_${XYZ}$ (:, j) - 3._wp*omega) + omega**2._wp) &
+                                                *(omega/(d_cbL_${XYZ}$ (:, j)**2._wp + omega*(1._wp - 2._wp*d_cbL_${XYZ}$ (:, j))))
 
                                     elseif (wenoz) then
                                         ! Castro, et al. (2010)
                                         ! Don & Borges (2013) also helps
                                         tau = abs(beta(3) - beta(0)) ! Equation 50
-                                        alpha = d_cbL_${XYZ}$ (:, j)*(1d0 + (tau/beta)**wenoz_q) ! q = 2,3,4 for stability
+                                        alpha = d_cbL_${XYZ}$ (:, j)*(1._wp + (tau/beta)**wenoz_q) ! q = 2,3,4 for stability
 
                                     elseif (teno) then
                                         tau = abs(beta(4) - beta(3)) ! Note the reordering of stencils
-                                        alpha = (1d0 + tau/beta)**6d0
+                                        alpha = (1._wp + tau/beta)**6._wp
                                         omega = alpha/sum(alpha)
-                                        delta = merge(0d0, 1d0, omega < teno_CT)
+                                        delta = merge(0._wp, 1._wp, omega < teno_CT)
                                         alpha = delta*d_cbL_${XYZ}$ (:, j)
 
                                     end if
@@ -1079,11 +1087,11 @@ contains
                                                   + poly_coef_cbR_${XYZ}$ (j, 3, 1)*dvd(-2) &
                                                   + poly_coef_cbR_${XYZ}$ (j, 3, 2)*dvd(-3)
                                     else
-                                        poly(0) = (-1d0*v(-1) +  5d0*v( 0) +  2d0*v( 1)) / 6d0 !&
-                                        poly(1) = ( 2d0*v( 0) +  5d0*v( 1) -  1d0*v( 2)) / 6d0 !&
-                                        poly(2) = ( 2d0*v(-2) -  7d0*v(-1) + 11d0*v( 0)) / 6d0 !&
-                                        poly(3) = ( 3d0*v( 0) + 13d0*v( 1) -  5d0*v( 2) +  1d0*v( 3)) / 12d0 !&
-                                        poly(4) = (-3d0*v(-3) + 13d0*v(-2) - 23d0*v(-1) + 25d0*v( 0)) / 12d0 !&
+                                        poly(0) = (-1._wp*v(-1) +  5._wp*v( 0) +  2._wp*v( 1)) / 6._wp !&
+                                        poly(1) = ( 2._wp*v( 0) +  5._wp*v( 1) -  1._wp*v( 2)) / 6._wp !&
+                                        poly(2) = ( 2._wp*v(-2) -  7._wp*v(-1) + 11._wp*v( 0)) / 6._wp !&
+                                        poly(3) = ( 3._wp*v( 0) + 13._wp*v( 1) -  5._wp*v( 2) +  1._wp*v( 3)) / 12._wp !&
+                                        poly(4) = (-3._wp*v(-3) + 13._wp*v(-2) - 23._wp*v(-1) + 25._wp*v( 0)) / 12._wp !&
                                     end if
 
                                     if (wenojs) then
@@ -1092,11 +1100,11 @@ contains
                                     elseif (mapped_weno) then
                                         alpha = d_cbR_${XYZ}$ (:, j)/(beta*beta)
                                         omega = alpha/sum(alpha)
-                                        alpha = (d_cbR_${XYZ}$ (:, j)*(1d0 + d_cbR_${XYZ}$ (:, j) - 3d0*omega) + omega**2d0) &
-                                                *(omega/(d_cbR_${XYZ}$ (:, j)**2d0 + omega*(1d0 - 2d0*d_cbR_${XYZ}$ (:, j))))
+                                        alpha = (d_cbR_${XYZ}$ (:, j)*(1._wp + d_cbR_${XYZ}$ (:, j) - 3._wp*omega) + omega**2._wp) &
+                                                *(omega/(d_cbR_${XYZ}$ (:, j)**2._wp + omega*(1._wp - 2._wp*d_cbR_${XYZ}$ (:, j))))
 
                                     elseif (wenoz) then
-                                        alpha = d_cbR_${XYZ}$ (:, j)*(1d0 + (tau/beta)**wenoz_q)
+                                        alpha = d_cbR_${XYZ}$ (:, j)*(1._wp + (tau/beta)**wenoz_q)
 
                                     elseif (teno) then
                                         alpha = delta*d_cbR_${XYZ}$ (:, j)
@@ -1250,41 +1258,41 @@ contains
         !!      stencil.
         !!  @param i Equation number
         !!  @param j First-coordinate cell index
-        !!  @param k Second-coordinate cell index
-        !!  @param l Third-coordinate cell index
+        !!  @param k Secone-coordinate cell index
+        !!  @param l Thire-coordinate cell index
     subroutine s_preserve_monotonicity(v_rs_ws, vL_rs_vf, vR_rs_vf)
 
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(IN) :: v_rs_ws
-        real(kind(0d0)), dimension(startx:, starty:, startz:, 1:), intent(INOUT) :: vL_rs_vf, vR_rs_vf
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(IN) :: v_rs_ws
+        real(wp), dimension(startx:, starty:, startz:, 1:), intent(INOUT) :: vL_rs_vf, vR_rs_vf
 
         integer :: i, j, k, l
 
-        real(kind(0d0)), dimension(-1:1) :: d !< Curvature measures at the zone centers
+        real(wp), dimension(-1:1) :: d !< Curvature measures at the zone centers
 
-        real(kind(0d0)) :: d_MD, d_LC !<
+        real(wp) :: d_MD, d_LC !<
             !! Median (md) curvature and large curvature (LC) measures
 
         ! The left and right upper bounds (UL), medians, large curvatures,
         ! minima, and maxima of the WENO-reconstructed values of the cell-
         ! average variables.
-        real(kind(0d0)) :: vL_UL, vR_UL
-        real(kind(0d0)) :: vL_MD, vR_MD
-        real(kind(0d0)) :: vL_LC, vR_LC
-        real(kind(0d0)) :: vL_min, vR_min
-        real(kind(0d0)) :: vL_max, vR_max
+        real(wp) :: vL_UL, vR_UL
+        real(wp) :: vL_MD, vR_MD
+        real(wp) :: vL_LC, vR_LC
+        real(wp) :: vL_min, vR_min
+        real(wp) :: vL_max, vR_max
 
-        real(kind(0d0)), parameter :: alpha = 2d0 !>
+        real(wp), parameter :: alpha = 2._wp !>
             !! Determines the maximum Courant–Friedrichs–Lewy (CFL) number that
             !! may be utilized with the scheme. In theory, for stability, a CFL
             !! number less than 1/(1+alpha) is necessary. The default value for
             !! alpha is 2.
 
-        real(kind(0d0)), parameter :: beta = 4d0/3d0 !<
+        real(wp), parameter :: beta = 4._wp/3._wp !<
             !! Determines the amount of freedom available from utilizing a large
             !! value for the local curvature. The default value for beta is 4/3.
 
-        real(kind(0d0)), parameter :: alpha_mp = 2d0
-        real(kind(0d0)), parameter :: beta_mp = 4d0/3d0
+        real(wp), parameter :: alpha_mp = 2._wp
+        real(wp), parameter :: beta_mp = 4._wp/3._wp
 
         !$acc parallel loop gang vector collapse (4)  default(present) private(d)
         do l = is3_weno%beg, is3_weno%end
@@ -1294,27 +1302,27 @@ contains
                         d(-1) = v_rs_ws(j, k, l, i) &
                                 + v_rs_ws(j - 2, k, l, i) &
                                 - v_rs_ws(j - 1, k, l, i) &
-                                *2d0
+                                *2._wp
                         d(0) = v_rs_ws(j + 1, k, l, i) &
                                + v_rs_ws(j - 1, k, l, i) &
                                - v_rs_ws(j, k, l, i) &
-                               *2d0
+                               *2._wp
                         d(1) = v_rs_ws(j + 2, k, l, i) &
                                + v_rs_ws(j, k, l, i) &
                                - v_rs_ws(j + 1, k, l, i) &
-                               *2d0
+                               *2._wp
 
-                        d_MD = (sign(1d0, 4d0*d(-1) - d(0)) + sign(1d0, 4d0*d(0) - d(-1))) &
-                               *abs((sign(1d0, 4d0*d(-1) - d(0)) + sign(1d0, d(-1))) &
-                                    *(sign(1d0, 4d0*d(-1) - d(0)) + sign(1d0, d(0)))) &
-                               *min(abs(4d0*d(-1) - d(0)), abs(d(-1)), &
-                                    abs(4d0*d(0) - d(-1)), abs(d(0)))/8d0
+                        d_MD = (sign(1._wp, 4._wp*d(-1) - d(0)) + sign(1._wp, 4._wp*d(0) - d(-1))) &
+                               *abs((sign(1._wp, 4._wp*d(-1) - d(0)) + sign(1._wp, d(-1))) &
+                                    *(sign(1._wp, 4._wp*d(-1) - d(0)) + sign(1._wp, d(0)))) &
+                               *min(abs(4._wp*d(-1) - d(0)), abs(d(-1)), &
+                                    abs(4._wp*d(0) - d(-1)), abs(d(0)))/8._wp
 
-                        d_LC = (sign(1d0, 4d0*d(0) - d(1)) + sign(1d0, 4d0*d(1) - d(0))) &
-                               *abs((sign(1d0, 4d0*d(0) - d(1)) + sign(1d0, d(0))) &
-                                    *(sign(1d0, 4d0*d(0) - d(1)) + sign(1d0, d(1)))) &
-                               *min(abs(4d0*d(0) - d(1)), abs(d(0)), &
-                                    abs(4d0*d(1) - d(0)), abs(d(1)))/8d0
+                        d_LC = (sign(1._wp, 4._wp*d(0) - d(1)) + sign(1._wp, 4._wp*d(1) - d(0))) &
+                               *abs((sign(1._wp, 4._wp*d(0) - d(1)) + sign(1._wp, d(0))) &
+                                    *(sign(1._wp, 4._wp*d(0) - d(1)) + sign(1._wp, d(1)))) &
+                               *min(abs(4._wp*d(0) - d(1)), abs(d(0)), &
+                                    abs(4._wp*d(1) - d(0)), abs(d(1)))/8._wp
 
                         vL_UL = v_rs_ws(j, k, l, i) &
                                 - (v_rs_ws(j + 1, k, l, i) &
@@ -1322,11 +1330,11 @@ contains
 
                         vL_MD = (v_rs_ws(j, k, l, i) &
                                  + v_rs_ws(j - 1, k, l, i) &
-                                 - d_MD)*5d-1
+                                 - d_MD)*5e-1_wp
 
                         vL_LC = v_rs_ws(j, k, l, i) &
                                 - (v_rs_ws(j + 1, k, l, i) &
-                                   - v_rs_ws(j, k, l, i))*5d-1 + beta_mp*d_LC
+                                   - v_rs_ws(j, k, l, i))*5e-1_wp + beta_mp*d_LC
 
                         vL_min = max(min(v_rs_ws(j, k, l, i), &
                                          v_rs_ws(j - 1, k, l, i), &
@@ -1343,8 +1351,8 @@ contains
                                          vL_LC))
 
                         vL_rs_vf(j, k, l, i) = vL_rs_vf(j, k, l, i) &
-                                               + (sign(5d-1, vL_min - vL_rs_vf(j, k, l, i)) &
-                                                  + sign(5d-1, vL_max - vL_rs_vf(j, k, l, i))) &
+                                               + (sign(5e-1_wp, vL_min - vL_rs_vf(j, k, l, i)) &
+                                                  + sign(5e-1_wp, vL_max - vL_rs_vf(j, k, l, i))) &
                                                *min(abs(vL_min - vL_rs_vf(j, k, l, i)), &
                                                     abs(vL_max - vL_rs_vf(j, k, l, i)))
                         ! END: Left Monotonicity Preserving Bound ==========================
@@ -1353,27 +1361,27 @@ contains
                         d(-1) = v_rs_ws(j, k, l, i) &
                                 + v_rs_ws(j - 2, k, l, i) &
                                 - v_rs_ws(j - 1, k, l, i) &
-                                *2d0
+                                *2._wp
                         d(0) = v_rs_ws(j + 1, k, l, i) &
                                + v_rs_ws(j - 1, k, l, i) &
                                - v_rs_ws(j, k, l, i) &
-                               *2d0
+                               *2._wp
                         d(1) = v_rs_ws(j + 2, k, l, i) &
                                + v_rs_ws(j, k, l, i) &
                                - v_rs_ws(j + 1, k, l, i) &
-                               *2d0
+                               *2._wp
 
-                        d_MD = (sign(1d0, 4d0*d(0) - d(1)) + sign(1d0, 4d0*d(1) - d(0))) &
-                               *abs((sign(1d0, 4d0*d(0) - d(1)) + sign(1d0, d(0))) &
-                                    *(sign(1d0, 4d0*d(0) - d(1)) + sign(1d0, d(1)))) &
-                               *min(abs(4d0*d(0) - d(1)), abs(d(0)), &
-                                    abs(4d0*d(1) - d(0)), abs(d(1)))/8d0
+                        d_MD = (sign(1._wp, 4._wp*d(0) - d(1)) + sign(1._wp, 4._wp*d(1) - d(0))) &
+                               *abs((sign(1._wp, 4._wp*d(0) - d(1)) + sign(1._wp, d(0))) &
+                                    *(sign(1._wp, 4._wp*d(0) - d(1)) + sign(1._wp, d(1)))) &
+                               *min(abs(4._wp*d(0) - d(1)), abs(d(0)), &
+                                    abs(4._wp*d(1) - d(0)), abs(d(1)))/8._wp
 
-                        d_LC = (sign(1d0, 4d0*d(-1) - d(0)) + sign(1d0, 4d0*d(0) - d(-1))) &
-                               *abs((sign(1d0, 4d0*d(-1) - d(0)) + sign(1d0, d(-1))) &
-                                    *(sign(1d0, 4d0*d(-1) - d(0)) + sign(1d0, d(0)))) &
-                               *min(abs(4d0*d(-1) - d(0)), abs(d(-1)), &
-                                    abs(4d0*d(0) - d(-1)), abs(d(0)))/8d0
+                        d_LC = (sign(1._wp, 4._wp*d(-1) - d(0)) + sign(1._wp, 4._wp*d(0) - d(-1))) &
+                               *abs((sign(1._wp, 4._wp*d(-1) - d(0)) + sign(1._wp, d(-1))) &
+                                    *(sign(1._wp, 4._wp*d(-1) - d(0)) + sign(1._wp, d(0)))) &
+                               *min(abs(4._wp*d(-1) - d(0)), abs(d(-1)), &
+                                    abs(4._wp*d(0) - d(-1)), abs(d(0)))/8._wp
 
                         vR_UL = v_rs_ws(j, k, l, i) &
                                 + (v_rs_ws(j, k, l, i) &
@@ -1381,11 +1389,11 @@ contains
 
                         vR_MD = (v_rs_ws(j, k, l, i) &
                                  + v_rs_ws(j + 1, k, l, i) &
-                                 - d_MD)*5d-1
+                                 - d_MD)*5e-1_wp
 
                         vR_LC = v_rs_ws(j, k, l, i) &
                                 + (v_rs_ws(j, k, l, i) &
-                                   - v_rs_ws(j - 1, k, l, i))*5d-1 + beta_mp*d_LC
+                                   - v_rs_ws(j - 1, k, l, i))*5e-1_wp + beta_mp*d_LC
 
                         vR_min = max(min(v_rs_ws(j, k, l, i), &
                                          v_rs_ws(j + 1, k, l, i), &
@@ -1402,8 +1410,8 @@ contains
                                          vR_LC))
 
                         vR_rs_vf(j, k, l, i) = vR_rs_vf(j, k, l, i) &
-                                               + (sign(5d-1, vR_min - vR_rs_vf(j, k, l, i)) &
-                                                  + sign(5d-1, vR_max - vR_rs_vf(j, k, l, i))) &
+                                               + (sign(5e-1_wp, vR_min - vR_rs_vf(j, k, l, i)) &
+                                                  + sign(5e-1_wp, vR_max - vR_rs_vf(j, k, l, i))) &
                                                *min(abs(vR_min - vR_rs_vf(j, k, l, i)), &
                                                     abs(vR_max - vR_rs_vf(j, k, l, i)))
                         ! END: Right Monotonicity Preserving Bound =========================
diff --git a/src/simulation/p_main.fpp b/src/simulation/p_main.fpp
index 18bab5a30..052695cc2 100644
--- a/src/simulation/p_main.fpp
+++ b/src/simulation/p_main.fpp
@@ -28,12 +28,12 @@ program p_main
     implicit none
 
     integer :: t_step !< Iterator for the time-stepping loop
-    real(kind(0d0)) :: time_avg, time_final
-    real(kind(0d0)) :: io_time_avg, io_time_final
-    real(kind(0d0)), allocatable, dimension(:) :: proc_time
-    real(kind(0d0)), allocatable, dimension(:) :: io_proc_time
+    real(wp) :: time_avg, time_final
+    real(wp) :: io_time_avg, io_time_final
+    real(wp), allocatable, dimension(:) :: proc_time
+    real(wp), allocatable, dimension(:) :: io_proc_time
     logical :: file_exists
-    real(kind(0d0)) :: start, finish
+    real(wp) :: start, finish
     integer :: nt
 
     call system_clock(COUNT=cpu_start, COUNT_RATE=cpu_rate)
@@ -64,7 +64,7 @@ program p_main
     else
         t_step = t_step_start
         if (t_step == 0) then
-            mytime = 0d0
+            mytime = 0._wp
         else
             mytime = t_step*dt
         end if
diff --git a/src/syscheck/syscheck.fpp b/src/syscheck/syscheck.fpp
index de613a6f8..ca2641057 100644
--- a/src/syscheck/syscheck.fpp
+++ b/src/syscheck/syscheck.fpp
@@ -53,7 +53,7 @@ program syscheck
 
     @:ACC(integer(acc_device_kind) :: devtype)
     @:ACC(integer :: i, num_devices)
-    @:ACC(real(kind(0d0)), allocatable, dimension(:) :: arr)
+    @:ACC(real(8), allocatable, dimension(:) :: arr)
     @:ACC(integer, parameter :: N = 100)
 
     @:MPIC(call mpi_init(ierr))
diff --git a/toolchain/mfc/build.py b/toolchain/mfc/build.py
index 156842a91..2de738986 100644
--- a/toolchain/mfc/build.py
+++ b/toolchain/mfc/build.py
@@ -133,6 +133,7 @@ def configure(self, case: Case):
             # Location prefix to install bin/, lib/, include/, etc.
             # See: https://cmake.org/cmake/help/latest/command/install.html.
             f"-DCMAKE_INSTALL_PREFIX={install_dirpath}",
+            f"-DMFC_SINGLE_PRECISION={'ON' if ARG('single') else 'OFF'}"
         ]
 
         if ARG("verbose"):
diff --git a/toolchain/mfc/run/input.py b/toolchain/mfc/run/input.py
index de8303643..126fb032b 100644
--- a/toolchain/mfc/run/input.py
+++ b/toolchain/mfc/run/input.py
@@ -5,7 +5,7 @@
 
 from ..printer import cons
 from ..        import common, build
-from ..state   import ARGS
+from ..state   import ARGS, ARG
 from ..case    import Case
 
 @dataclasses.dataclass(init=False)
@@ -69,17 +69,24 @@ def generate_fpp(self, target) -> None:
         # (Thermo)Chemistry source file
         modules_dir = os.path.join(target.get_staging_dirpath(self), "modules", target.name)
         common.create_directory(modules_dir)
+
+        # Determine the real type based on the single precision flag
+        real_type = 'real(sp)' if ARG('single') else 'real(dp)'
+
+        # Write the generated Fortran code to the m_thermochem.f90 file with the chosen precision
         common.file_write(
             os.path.join(modules_dir, "m_thermochem.f90"),
             pyro.codegen.fortran90.gen_thermochem_code(
                 self.get_cantera_solution(),
-                module_name="m_thermochem"
+                module_name="m_thermochem",
+                real_type=real_type
             ),
             True
         )
 
         cons.unindent()
 
+
     # Generate case.fpp & [target.name].inp
     def generate(self, target) -> None:
         self.generate_inp(target)
diff --git a/toolchain/mfc/state.py b/toolchain/mfc/state.py
index 7c21408a2..fa7d438e7 100644
--- a/toolchain/mfc/state.py
+++ b/toolchain/mfc/state.py
@@ -8,6 +8,7 @@ class MFCConfig:
     debug:   bool = False
     gcov:    bool = False
     unified: bool = False
+    single: bool = False
 
     @staticmethod
     def from_dict(d: dict):
diff --git a/toolchain/mfc/test/case.py b/toolchain/mfc/test/case.py
index 2961d9798..55cc73ec9 100644
--- a/toolchain/mfc/test/case.py
+++ b/toolchain/mfc/test/case.py
@@ -227,22 +227,28 @@ def compute_tolerance(self) -> float:
         if self.override_tol:
             return self.override_tol
 
-        tolerance = 1e-12 # Default
+        tolerance = 1e-12  # Default
+        single = ARG("single")
+
         if "Example" in self.trace.split(" -> "):
             tolerance = 1e-3
         elif self.params.get("hypoelasticity", 'F') == 'T':
             tolerance = 1e-7
+        elif self.params.get("mixlayer_perturb", 'F') == 'T':
+            tolerance = 1e-7
         elif any(self.params.get(key, 'F') == 'T' for key in ['relax', 'ib', 'qbmm', 'bubbles']):
             tolerance = 1e-10
         elif self.params.get("low_Mach") in [1, 2]:
             tolerance = 1e-10
         elif self.params.get("acoustic_source", 'F') == 'T':
             if self.params.get("acoustic(1)%pulse") == 3:  # Square wave
-                tolerance = 1e-5
-            else:
-                tolerance = 3e-12
+                return 1e-1 if single else 1e-5
+            tolerance = 3e-12
+        elif self.params.get("weno_order") == 7:
+            tolerance = 1e-9
+
+        return 1e8 * tolerance if single else tolerance
 
-        return tolerance
 
 
 @dataclasses.dataclass
diff --git a/toolchain/mfc/test/cases.py b/toolchain/mfc/test/cases.py
index 8d78af9f2..60829af0b 100644
--- a/toolchain/mfc/test/cases.py
+++ b/toolchain/mfc/test/cases.py
@@ -532,8 +532,8 @@ def alter_hypoelasticity(dimInfo):
                 'patch_icpp(1)%pres':         1.E+06, 'patch_icpp(1)%alpha_rho(1)': 1000.E+00,
                 'patch_icpp(2)%pres':         1.E+05, 'patch_icpp(2)%alpha_rho(1)': 1000.E+00,
                 'patch_icpp(3)%pres':         5.E+05, 'patch_icpp(3)%alpha_rho(1)': 1000.E+00,
-                'patch_icpp(1)%tau_e(1)':     0.E+00, 'patch_icpp(2)%tau_e(1)':     0.E+00,
-                'patch_icpp(3)%tau_e(1)':     0.E+00, 'fluid_pp(1)%G':              1.E+05,
+                'patch_icpp(1)%tau_e(1)':     0.E-00, 'patch_icpp(2)%tau_e(1)':     0.E-00,
+                'patch_icpp(3)%tau_e(1)':     0.E-00, 'fluid_pp(1)%G':              1.E+05,
             })
 
             if num_fluids == 2:
diff --git a/toolchain/mfc/test/test.py b/toolchain/mfc/test/test.py
index 9dfaab3e8..248bf4b5a 100644
--- a/toolchain/mfc/test/test.py
+++ b/toolchain/mfc/test/test.py
@@ -21,6 +21,7 @@
 nSKIP = 0
 errors = []
 
+# pylint: disable=too-many-branches, trailing-whitespace
 def __filter(cases_) -> typing.List[TestCase]:
     cases = cases_[:]
     selected_cases = []
@@ -55,6 +56,14 @@ def __filter(cases_) -> typing.List[TestCase]:
         if case.ppn > 1 and not ARG("mpi"):
             cases.remove(case)
             skipped_cases.append(case)
+    
+    for case in cases[:]:
+        if ARG("single"):
+            skip = ['low_Mach', 'Hypoelasticity', 'teno', 'Chemistry', 'Phase Change model 6'
+            ,'Axisymmetric', 'Transducer', 'Transducer Array', 'Cylindrical', 'Example']
+            if any(label in case.trace for label in skip):
+                cases.remove(case)
+
 
     if ARG("no_examples"):
         cases = [case for case in cases if not "Example" in case.trace]
@@ -156,14 +165,14 @@ def test():
     exit(nFAIL)
 
 
-# pylint: disable=too-many-locals, too-many-branches, too-many-statements
+# pylint: disable=too-many-locals, too-many-branches, too-many-statements, trailing-whitespace
 def _handle_case(case: TestCase, devices: typing.Set[int]):
+    # pylint: disable=global-statement, global-variable-not-assigned
     start_time = time.time()
 
     tol = case.compute_tolerance()
     case.delete_output()
     case.create_directory()
-
     cmd = case.run([PRE_PROCESS, SIMULATION], gpus=devices)
     out_filepath = os.path.join(case.get_dirpath(), "out_pre_sim.txt")
 
@@ -242,6 +251,10 @@ def handle_case(case: TestCase, devices: typing.Set[int]):
     global errors
 
     nAttempts = 0
+    if ARG('single'):
+        max_attempts = max(ARG('max_attempts'), 3)
+    else:
+        max_attempts = ARG('max_attempts')
 
     while True:
         nAttempts += 1
@@ -250,9 +263,7 @@ def handle_case(case: TestCase, devices: typing.Set[int]):
             _handle_case(case, devices)
             nPASS += 1
         except Exception as exc:
-            if nAttempts < ARG("max_attempts"):
-                cons.print(f"[bold yellow] Attempt {nAttempts}: Failed test {case.get_uuid()}. Retrying...[/bold yellow]")
-                errors.append(f"[bold yellow] Attempt {nAttempts}: Failed test {case.get_uuid()}. Retrying...[/bold yellow]")
+            if nAttempts < max_attempts:
                 continue
             nFAIL += 1
             cons.print(f"[bold red]Failed test {case} after {nAttempts} attempt(s).[/bold red]")