refactor: move dx/dy/dz min spacing into grid_axis%min_spacing

Remove module-level dx, dy, dz scalars from pre_process m_global_parameters.
Add min_spacing field to the grid_axis derived type so each axis carries its
own minimum cell width. Update all call sites in m_grid, m_start_up,
m_icpp_patches, m_mpi_common, and 2dHardcodedIC.

Author: sbryngelson

src/common/include/2dHardcodedIC.fpp

@@ -157,7 +157,7 @@
         if (x%cc(i) <= 0.7_wp*lam) then
             d = x%cc(i) - lam*(0.4_wp - 0.1_wp*sin(2.0_wp*pi*(y%cc(j)/lam + 0.25_wp)))
 #ifdef MFC_PRE_PROCESS
-            fsm = 0.5_wp*(1.0_wp + erf(d/(ei*sqrt(dx*dy))))
+            fsm = 0.5_wp*(1.0_wp + erf(d/(ei*sqrt(x%min_spacing*y%min_spacing))))
 #else
             fsm = 0.5_wp*(1.0_wp + erf(d/(ei*sqrt(x%spacing(i)*y%spacing(j)))))
 #endif

src/common/m_derived_types.fpp

@@ -13,9 +13,10 @@ module m_derived_types
 
     implicit none
 
-    !> Derived type for a single spatial grid axis: cell-boundary, cell-center, and per-cell spacing arrays
+    !> Derived type for a single spatial grid axis: cell-boundary, cell-center, per-cell spacing arrays, and minimum spacing scalar
     type grid_axis
         real(wp), allocatable, dimension(:) :: cb, cc, spacing
+        real(wp)                            :: min_spacing = 0._wp
     end type grid_axis
 
     !> Derived type adding the field position (fp) as an attribute

src/common/m_mpi_common.fpp

@@ -1022,12 +1022,15 @@ contains
         integer :: num_procs_x, num_procs_y, num_procs_z  !< Optimal number of processors in the x-, y- and z-directions
         !> Non-optimal number of processors in the x-, y- and z-directions
         real(wp) :: tmp_num_procs_x, tmp_num_procs_y, tmp_num_procs_z
-        real(wp) :: fct_min        !< Processor factorization (fct) minimization parameter
-        integer  :: MPI_COMM_CART  !< Cartesian processor topology communicator
-        integer  :: rem_cells      !< Remaining cells after distribution among processors
-        integer  :: recon_order    !< WENO or MUSCL reconstruction order
-        integer  :: i, j           !< Generic loop iterators
-        integer  :: ierr           !< Generic flag used to identify and report MPI errors
+        real(wp) :: fct_min  !< Processor factorization (fct) minimization parameter
+#ifdef MFC_PRE_PROCESS
+        real(wp) :: dx, dy, dz  !< uniform spacing temporaries for domain decomposition
+#endif
+        integer :: MPI_COMM_CART  !< Cartesian processor topology communicator
+        integer :: rem_cells      !< Remaining cells after distribution among processors
+        integer :: recon_order    !< WENO or MUSCL reconstruction order
+        integer :: i, j           !< Generic loop iterators
+        integer :: ierr           !< Generic flag used to identify and report MPI errors
 
         if (recon_type == WENO_TYPE) then
             recon_order = weno_order

src/pre_process/m_global_parameters.fpp

@@ -41,9 +41,8 @@ module m_global_parameters
     integer               :: num_vels             !< Number of velocity components (different from num_dims for mhd)
     logical               :: cyl_coord
     integer               :: grid_geometry        !< Cylindrical coordinates (either axisymmetric or full 3D)
-    !> Cell-boundary (cb) and cell-center (cc) arrays per direction
+    !> Cell-boundary (cb), cell-center (cc), per-cell spacing, and minimum spacing per direction
     type(grid_axis)   :: x, y, z
-    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  !< Locations of the domain bounds in the x-, y- and z-coordinate directions
     logical           :: stretch_x, stretch_y, stretch_z  !< Grid stretching flags for the x-, y- and z-coordinate directions
     ! Grid stretching: a_x/a_y/a_z = rate, x_stretch%beg/end = locations

src/pre_process/m_grid.f90

@@ -34,8 +34,9 @@ end subroutine s_generate_abstract_grid
     impure subroutine s_generate_serial_grid
 
         ! Generic loop iterator
-        integer  :: i, j    !< generic loop operators
-        real(wp) :: length  !< domain lengths
+        integer  :: i, j        !< generic loop operators
+        real(wp) :: length      !< domain lengths
+        real(wp) :: dx, dy, dz  !< local uniform spacing temporaries
         ! Uniform grid: dx = (x_end - x_beg) / (m + 1)
 
         dx = (x_domain%end - x_domain%beg)/real(m + 1, wp)
@@ -68,6 +69,7 @@ impure subroutine s_generate_serial_grid
             print *, 'Stretched grid: min/max x grid: ', minval(x%cc(:)), maxval(x%cc(:))
             if (num_procs > 1) call s_mpi_reduce_min(dx)
         end if
+        x%min_spacing = dx
 
         ! Grid Generation in the y-direction
         if (n == 0) return
@@ -115,6 +117,7 @@ impure subroutine s_generate_serial_grid
 
             if (num_procs > 1) call s_mpi_reduce_min(dy)
         end if
+        y%min_spacing = dy
 
         ! Grid Generation in the z-direction
         if (p == 0) return
@@ -149,14 +152,16 @@ impure subroutine s_generate_serial_grid
 
             if (num_procs > 1) call s_mpi_reduce_min(dz)
         end if
+        z%min_spacing = dz
 
     end subroutine s_generate_serial_grid
 
     !> Generate a uniform or stretched rectilinear grid in parallel from user parameters.
     impure subroutine s_generate_parallel_grid
 
 #ifdef MFC_MPI
-        real(wp) :: length  !< domain lengths
+        real(wp) :: length      !< domain lengths
+        real(wp) :: dx, dy, dz  !< local uniform spacing temporaries
         ! Locations of cell boundaries
         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                      !< Generic string used to store the address of a file

src/pre_process/m_icpp_patches.fpp

@@ -312,8 +312,9 @@ contains
             do i = 0, m
                 if (patch_icpp(patch_id)%smoothen) then
                     ! Smooth Heaviside via hyperbolic tangent; smooth_coeff controls interface sharpness
-                    eta = tanh(smooth_coeff/min(dx, &
-                               & dy)*(sqrt((x%cc(i) - x_centroid)**2 + (y%cc(j) - y_centroid)**2) - radius))*(-0.5_wp) + 0.5_wp
+                    eta = tanh(smooth_coeff/min(x%min_spacing, &
+                               & y%min_spacing)*(sqrt((x%cc(i) - x_centroid)**2 + (y%cc(j) - y_centroid)**2) - radius))*(-0.5_wp) &
+                               & + 0.5_wp
                 end if
 
                 if (((x%cc(i) - x_centroid)**2 + (y%cc(j) - y_centroid)**2 <= radius**2 &
@@ -485,9 +486,9 @@ contains
         do j = 0, n
             do i = 0, m
                 if (patch_icpp(patch_id)%smoothen) then
-                    eta = tanh(smooth_coeff/min(dx, &
-                               & dy)*(sqrt(((x%cc(i) - x_centroid)/a)**2 + ((y%cc(j) - y_centroid)/b)**2) - 1._wp))*(-0.5_wp) &
-                               & + 0.5_wp
+                    eta = tanh(smooth_coeff/min(x%min_spacing, &
+                               & y%min_spacing)*(sqrt(((x%cc(i) - x_centroid)/a)**2 + ((y%cc(j) - y_centroid)/b)**2) - 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 <= 1._wp &
@@ -555,8 +556,8 @@ contains
                     end if
 
                     if (patch_icpp(patch_id)%smoothen) then
-                        eta = tanh(smooth_coeff/min(dx, dy, &
-                                   & dz)*(sqrt(((x%cc(i) - x_centroid)/a)**2 + ((cart_y - y_centroid)/b)**2 + ((cart_z &
+                        eta = tanh(smooth_coeff/min(x%min_spacing, y%min_spacing, &
+                                   & z%min_spacing)*(sqrt(((x%cc(i) - x_centroid)/a)**2 + ((cart_y - y_centroid)/b)**2 + ((cart_z &
                                    & - z_centroid)/c)**2) - 1._wp))*(-0.5_wp) + 0.5_wp
                     end if
 
@@ -688,7 +689,8 @@ contains
         do j = 0, n
             do i = 0, m
                 if (patch_icpp(patch_id)%smoothen) then
-                    eta = 5.e-1_wp + 5.e-1_wp*tanh(smooth_coeff/min(dx, dy)*(a*x%cc(i) + b*y%cc(j) + c)/sqrt(a**2 + b**2))
+                    eta = 5.e-1_wp + 5.e-1_wp*tanh(smooth_coeff/min(x%min_spacing, &
+                                                   & y%min_spacing)*(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 >= 0._wp .and. patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, &
@@ -878,7 +880,7 @@ contains
                     end if
                 end if
                 if (patch_icpp(patch_id)%smoothen) then
-                    eta = 0.5_wp + 0.5_wp*tanh(smooth_coeff/min(dx, dy)*(R_boundary - r))
+                    eta = 0.5_wp + 0.5_wp*tanh(smooth_coeff/min(x%min_spacing, y%min_spacing)*(R_boundary - r))
                 end if
                 if ((r <= R_boundary .and. patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, 0))) .or. patch_id_fp(i, j, &
                     & 0) == smooth_patch_id) then
@@ -940,7 +942,8 @@ contains
                         end do
                     end do
                     if (patch_icpp(patch_id)%smoothen) then
-                        eta_local = 0.5_wp + 0.5_wp*tanh(smooth_coeff/min(dx, dy, dz)*(R_surface - r))
+                        eta_local = 0.5_wp + 0.5_wp*tanh(smooth_coeff/min(x%min_spacing, y%min_spacing, &
+                                                         & z%min_spacing)*(R_surface - r))
                     end if
                     if ((r <= R_surface .and. patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, k))) .or. patch_id_fp(i, j, &
                         & k) == smooth_patch_id) then
@@ -998,9 +1001,9 @@ contains
                     end if
 
                     if (patch_icpp(patch_id)%smoothen) then
-                        eta = tanh(smooth_coeff/min(dx, dy, &
-                                   & dz)*(sqrt((x%cc(i) - x_centroid)**2 + (cart_y - y_centroid)**2 + (cart_z - z_centroid)**2) &
-                                   & - radius))*(-0.5_wp) + 0.5_wp
+                        eta = tanh(smooth_coeff/min(x%min_spacing, y%min_spacing, &
+                                   & z%min_spacing)*(sqrt((x%cc(i) - x_centroid)**2 + (cart_y - y_centroid)**2 + (cart_z &
+                                   & - z_centroid)**2) - radius))*(-0.5_wp) + 0.5_wp
                     end if
 
                     if ((((x%cc(i) - x_centroid)**2 + (cart_y - y_centroid)**2 + (cart_z - z_centroid)**2 <= radius**2) &
@@ -1146,17 +1149,17 @@ contains
 
                     if (patch_icpp(patch_id)%smoothen) then
                         if (.not. f_is_default(length_x)) then
-                            eta = tanh(smooth_coeff/min(dy, &
-                                       & dz)*(sqrt((cart_y - y_centroid)**2 + (cart_z - z_centroid)**2) - radius))*(-0.5_wp) &
-                                       & + 0.5_wp
+                            eta = tanh(smooth_coeff/min(y%min_spacing, &
+                                       & z%min_spacing)*(sqrt((cart_y - y_centroid)**2 + (cart_z - z_centroid)**2) - radius)) &
+                                       & *(-0.5_wp) + 0.5_wp
                         else if (.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))*(-0.5_wp) &
-                                       & + 0.5_wp
+                            eta = tanh(smooth_coeff/min(x%min_spacing, &
+                                       & z%min_spacing)*(sqrt((x%cc(i) - x_centroid)**2 + (cart_z - z_centroid)**2) - 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))*(-0.5_wp) &
-                                       & + 0.5_wp
+                            eta = tanh(smooth_coeff/min(x%min_spacing, &
+                                       & y%min_spacing)*(sqrt((x%cc(i) - x_centroid)**2 + (cart_y - y_centroid)**2) - radius)) &
+                                       & *(-0.5_wp) + 0.5_wp
                         end if
                     end if
 
@@ -1232,8 +1235,9 @@ contains
                     end if
 
                     if (patch_icpp(patch_id)%smoothen) then
-                        eta = 5.e-1_wp + 5.e-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))
+                        eta = 5.e-1_wp + 5.e-1_wp*tanh(smooth_coeff/min(x%min_spacing, y%min_spacing, &
+                                                       & z%min_spacing)*(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 >= 0._wp .and. patch_icpp(patch_id)%alter_patch(patch_id_fp(i, j, &
@@ -1326,11 +1330,11 @@ contains
             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)
 
-            grid_mm(1,:) = (/minval(x%cc) - 0.e5_wp*dx, maxval(x%cc) + 0.e5_wp*dx/)
-            grid_mm(2,:) = (/minval(y%cc) - 0.e5_wp*dy, maxval(y%cc) + 0.e5_wp*dy/)
+            grid_mm(1,:) = (/minval(x%cc) - 0.e5_wp*x%min_spacing, maxval(x%cc) + 0.e5_wp*x%min_spacing/)
+            grid_mm(2,:) = (/minval(y%cc) - 0.e5_wp*y%min_spacing, maxval(y%cc) + 0.e5_wp*y%min_spacing/)
 
             if (p > 0) then
-                grid_mm(3,:) = (/minval(z%cc) - 0.e5_wp*dz, maxval(z%cc) + 0.e5_wp*dz/)
+                grid_mm(3,:) = (/minval(z%cc) - 0.e5_wp*z%min_spacing, maxval(z%cc) + 0.e5_wp*z%min_spacing/)
             else
                 grid_mm(3,:) = (/0._wp, 0._wp/)
             end if
@@ -1356,7 +1360,7 @@ contains
                 point = f_convert_cyl_to_cart(point)
             end if
 
-            eta = f_model_is_inside(model, point, (/dx, dy, dz/), patch_icpp(patch_id)%model_spc)
+            eta = f_model_is_inside(model, point, (/x%min_spacing, y%min_spacing, z%min_spacing/), patch_icpp(patch_id)%model_spc)
 
             if (eta > patch_icpp(patch_id)%model_threshold) then
                 eta = 1._wp

src/pre_process/m_start_up.fpp

@@ -181,8 +181,8 @@ contains
 
         x%cc(0:m) = (x%cb(0:m) + x%cb(-1:(m - 1)))/2._wp
 
-        dx = minval(x%cb(0:m) - x%cb(-1:m - 1))
-        if (num_procs > 1) call s_mpi_reduce_min(dx)
+        x%min_spacing = minval(x%cb(0:m) - x%cb(-1:m - 1))
+        if (num_procs > 1) call s_mpi_reduce_min(x%min_spacing)
 
         x_domain%beg = x%cb(-1)
         x_domain%end = x%cb(m)
@@ -201,8 +201,8 @@ contains
 
             y%cc(0:n) = (y%cb(0:n) + y%cb(-1:(n - 1)))/2._wp
 
-            dy = minval(y%cb(0:n) - y%cb(-1:n - 1))
-            if (num_procs > 1) call s_mpi_reduce_min(dy)
+            y%min_spacing = minval(y%cb(0:n) - y%cb(-1:n - 1))
+            if (num_procs > 1) call s_mpi_reduce_min(y%min_spacing)
 
             y_domain%beg = y%cb(-1)
             y_domain%end = y%cb(n)
@@ -221,8 +221,8 @@ contains
 
                 z%cc(0:p) = (z%cb(0:p) + z%cb(-1:(p - 1)))/2._wp
 
-                dz = minval(z%cb(0:p) - z%cb(-1:p - 1))
-                if (num_procs > 1) call s_mpi_reduce_min(dz)
+                z%min_spacing = minval(z%cb(0:p) - z%cb(-1:p - 1))
+                if (num_procs > 1) call s_mpi_reduce_min(z%min_spacing)
 
                 z_domain%beg = z%cb(-1)
                 z_domain%end = z%cb(p)
@@ -354,8 +354,8 @@ contains
 
         x%cb(-1:m) = x_cb_glb((start_idx(1) - 1):(start_idx(1) + m))
         x%cc(0:m) = (x%cb(0:m) + x%cb(-1:(m - 1)))/2._wp
-        dx = minval(x%cb(0:m) - x%cb(-1:(m - 1)))
-        if (num_procs > 1) call s_mpi_reduce_min(dx)
+        x%min_spacing = minval(x%cb(0:m) - x%cb(-1:(m - 1)))
+        if (num_procs > 1) call s_mpi_reduce_min(x%min_spacing)
         x_domain%beg = x%cb(-1)
         x_domain%end = x%cb(m)
 
@@ -374,8 +374,8 @@ contains
 
             y%cb(-1:n) = y_cb_glb((start_idx(2) - 1):(start_idx(2) + n))
             y%cc(0:n) = (y%cb(0:n) + y%cb(-1:(n - 1)))/2._wp
-            dy = minval(y%cb(0:n) - y%cb(-1:(n - 1)))
-            if (num_procs > 1) call s_mpi_reduce_min(dy)
+            y%min_spacing = minval(y%cb(0:n) - y%cb(-1:(n - 1)))
+            if (num_procs > 1) call s_mpi_reduce_min(y%min_spacing)
             y_domain%beg = y%cb(-1)
             y_domain%end = y%cb(n)
 
@@ -394,8 +394,8 @@ contains
 
                 z%cb(-1:p) = z_cb_glb((start_idx(3) - 1):(start_idx(3) + p))
                 z%cc(0:p) = (z%cb(0:p) + z%cb(-1:(p - 1)))/2._wp
-                dz = minval(z%cb(0:p) - z%cb(-1:(p - 1)))
-                if (num_procs > 1) call s_mpi_reduce_min(dz)
+                z%min_spacing = minval(z%cb(0:p) - z%cb(-1:(p - 1)))
+                if (num_procs > 1) call s_mpi_reduce_min(z%min_spacing)
                 z_domain%beg = z%cb(-1)
                 z_domain%end = z%cb(p)
             end if