!> @file diffusion_w.f90 !--------------------------------------------------------------------------------------------------! ! This file is part of the PALM model system. ! ! PALM is free software: you can redistribute it and/or modify it under the terms of the GNU General ! Public License as published by the Free Software Foundation, either version 3 of the License, or ! (at your option) any later version. ! ! PALM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the ! implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General ! Public License for more details. ! ! You should have received a copy of the GNU General Public License along with PALM. If not, see ! <http://www.gnu.org/licenses/>. ! ! Copyright 1997-2021 Leibniz Universitaet Hannover !--------------------------------------------------------------------------------------------------! ! ! Current revisions: ! ----------------- ! ! ! Former revisions: ! ----------------- ! $Id: diffusion_w.f90 4828 2021-01-05 11:21:41Z Giersch $ ! file re-formatted to follow the PALM coding standard ! ! 4360 2020-01-07 11:25:50Z suehring ! Introduction of wall_flags_total_0, which currently sets bits based on static topography ! information used in wall_flags_static_0 ! ! 4329 2019-12-10 15:46:36Z motisi ! Renamed wall_flags_0 to wall_flags_static_0 ! ! 4182 2019-08-22 15:20:23Z scharf ! Corrected "Former revisions" section ! ! 3655 2019-01-07 16:51:22Z knoop ! OpenACC port for SPEC ! ! Revision 1.1 1997/09/12 06:24:11 raasch ! Initial revision ! ! ! Description: ! ------------ !> Diffusion term of the w-component !--------------------------------------------------------------------------------------------------! MODULE diffusion_w_mod PRIVATE PUBLIC diffusion_w INTERFACE diffusion_w MODULE PROCEDURE diffusion_w MODULE PROCEDURE diffusion_w_ij END INTERFACE diffusion_w CONTAINS !--------------------------------------------------------------------------------------------------! ! Description: ! ------------ !> Call for all grid points !--------------------------------------------------------------------------------------------------! SUBROUTINE diffusion_w USE arrays_3d, & ONLY : ddzu, ddzw, drho_air_zw, km, rho_air, tend, u, v, w USE grid_variables, & ONLY : ddx, ddy USE indices, & ONLY : nxl, nxr, nyn, nys, nzb, nzt, wall_flags_total_0 USE kinds USE surface_mod, & ONLY : surf_def_v, surf_lsm_v, surf_usm_v IMPLICIT NONE INTEGER(iwp) :: i !< running index x direction INTEGER(iwp) :: j !< running index y direction INTEGER(iwp) :: k !< running index z direction INTEGER(iwp) :: l !< running index of surface type, south- or north-facing wall INTEGER(iwp) :: m !< running index surface elements INTEGER(iwp) :: surf_e !< End index of surface elements at (j,i)-gridpoint INTEGER(iwp) :: surf_s !< Start index of surface elements at (j,i)-gridpoint REAL(wp) :: flag !< flag to mask topography grid points REAL(wp) :: kmxm !< diffusion coefficient on leftward side of the w-gridbox - interpolated onto xu-y grid REAL(wp) :: kmxp !<diffusion coefficient on rightward side of the w-gridbox - interpolated onto xu-y grid REAL(wp) :: kmym !< diffusion coefficient on southward side of the w-gridbox - interpolated onto x-yv grid REAL(wp) :: kmyp !< diffusion coefficient on northward side of the w-gridbox - interpolated onto x-yv grid REAL(wp) :: mask_east !< flag to mask vertical wall east of the grid point REAL(wp) :: mask_north !< flag to mask vertical wall north of the grid point REAL(wp) :: mask_south !< flag to mask vertical wall south of the grid point REAL(wp) :: mask_west !< flag to mask vertical wall west of the grid point !$ACC PARALLEL LOOP COLLAPSE(2) PRIVATE(i, j, k, l, m) & !$ACC PRIVATE(surf_e, surf_s, flag, kmxm, kmxp, kmym, kmyp) & !$ACC PRIVATE(mask_west, mask_east, mask_south, mask_north) & !$ACC PRESENT(wall_flags_total_0, km) & !$ACC PRESENT(u, v, w) & !$ACC PRESENT(ddzu, ddzw, rho_air, drho_air_zw) & !$ACC PRESENT(surf_def_v(0:3)) & !$ACC PRESENT(surf_lsm_v(0:3)) & !$ACC PRESENT(surf_usm_v(0:3)) & !$ACC PRESENT(tend) DO i = nxl, nxr DO j = nys, nyn DO k = nzb+1, nzt-1 ! !-- Predetermine flag to mask topography and wall-bounded grid points. flag = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j,i), 3 ) ) mask_east = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j,i+1), 3 ) ) mask_west = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j,i-1), 3 ) ) mask_south = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j-1,i), 3 ) ) mask_north = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j+1,i), 3 ) ) ! !-- Interpolate eddy diffusivities on staggered gridpoints kmxp = 0.25_wp * ( km(k,j,i) + km(k,j,i+1) + & km(k+1,j,i) + km(k+1,j,i+1) ) kmxm = 0.25_wp * ( km(k,j,i) + km(k,j,i-1) + & km(k+1,j,i) + km(k+1,j,i-1) ) kmyp = 0.25_wp * ( km(k,j,i) + km(k+1,j,i) + & km(k,j+1,i) + km(k+1,j+1,i) ) kmym = 0.25_wp * ( km(k,j,i) + km(k+1,j,i) + & km(k,j-1,i) + km(k+1,j-1,i) ) tend(k,j,i) = tend(k,j,i) & + ( mask_east * kmxp * ( & ( w(k,j,i+1) - w(k,j,i) ) * ddx & + ( u(k+1,j,i+1) - u(k,j,i+1) ) * ddzu(k+1) & ) & - mask_west * kmxm * ( & ( w(k,j,i) - w(k,j,i-1) ) * ddx & + ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & ) & ) * ddx * flag & + ( mask_north * kmyp * ( & ( w(k,j+1,i) - w(k,j,i) ) * ddy & + ( v(k+1,j+1,i) - v(k,j+1,i) ) * ddzu(k+1) & ) & - mask_south * kmym * ( & ( w(k,j,i) - w(k,j-1,i) ) * ddy & + ( v(k+1,j,i) - v(k,j,i) ) * ddzu(k+1) & ) & ) * ddy * flag & + 2.0_wp * ( & km(k+1,j,i) * ( w(k+1,j,i) - w(k,j,i) ) * ddzw(k+1) & * rho_air(k+1) & - km(k,j,i) * ( w(k,j,i) - w(k-1,j,i) ) * ddzw(k) & * rho_air(k) & ) * ddzu(k+1) * drho_air_zw(k) * flag ENDDO ! !-- Add horizontal momentum flux v'w' at north- (l=0) and south-facing (l=1) surfaces. !-- Note, in the the flat case, loops won't be entered as start_index > end_index. !-- Furtermore, note, no vertical natural surfaces so far. !-- Default-type surfaces DO l = 0, 1 surf_s = surf_def_v(l)%start_index(j,i) surf_e = surf_def_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_def_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_def_v(l)%mom_flux_w(m) * ddy ENDDO ENDDO ! !-- Natural-type surfaces DO l = 0, 1 surf_s = surf_lsm_v(l)%start_index(j,i) surf_e = surf_lsm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_lsm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_lsm_v(l)%mom_flux_w(m) * ddy ENDDO ENDDO ! !-- Urban-type surfaces DO l = 0, 1 surf_s = surf_usm_v(l)%start_index(j,i) surf_e = surf_usm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_usm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_usm_v(l)%mom_flux_w(m) * ddy ENDDO ENDDO ! !-- Add horizontal momentum flux u'w' at east- (l=2) and west-facing (l=3) surface. !-- Default-type surfaces DO l = 2, 3 surf_s = surf_def_v(l)%start_index(j,i) surf_e = surf_def_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_def_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_def_v(l)%mom_flux_w(m) * ddx ENDDO ENDDO ! !-- Natural-type surfaces DO l = 2, 3 surf_s = surf_lsm_v(l)%start_index(j,i) surf_e = surf_lsm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_lsm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_lsm_v(l)%mom_flux_w(m) * ddx ENDDO ENDDO ! !-- Urban-type surfaces DO l = 2, 3 surf_s = surf_usm_v(l)%start_index(j,i) surf_e = surf_usm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_usm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_usm_v(l)%mom_flux_w(m) * ddx ENDDO ENDDO ENDDO ENDDO END SUBROUTINE diffusion_w !--------------------------------------------------------------------------------------------------! ! Description: ! ------------ !> Call for grid point i,j !--------------------------------------------------------------------------------------------------! SUBROUTINE diffusion_w_ij( i, j ) USE arrays_3d, & ONLY : ddzu, ddzw, drho_air_zw, km, rho_air, tend, u, v, w USE grid_variables, & ONLY : ddx, ddy USE indices, & ONLY : nzb, nzt, wall_flags_total_0 USE kinds USE surface_mod, & ONLY : surf_def_v, surf_lsm_v, surf_usm_v IMPLICIT NONE INTEGER(iwp) :: i !< running index x direction INTEGER(iwp) :: j !< running index y direction INTEGER(iwp) :: k !< running index z direction INTEGER(iwp) :: l !< running index of surface type, south- or north-facing wall INTEGER(iwp) :: m !< running index surface elements INTEGER(iwp) :: surf_e !< End index of surface elements at (j,i)-gridpoint INTEGER(iwp) :: surf_s !< Start index of surface elements at (j,i)-gridpoint REAL(wp) :: flag !< flag to mask topography grid points REAL(wp) :: kmxm !< diffusion coefficient on leftward side of the w-gridbox - interpolated onto xu-y grid REAL(wp) :: kmxp !< diffusion coefficient on rightward side of the w-gridbox - interpolated onto xu-y grid REAL(wp) :: kmym !< diffusion coefficient on southward side of the w-gridbox - interpolated onto x-yv grid REAL(wp) :: kmyp !< diffusion coefficient on northward side of the w-gridbox - interpolated onto x-yv grid REAL(wp) :: mask_east !< flag to mask vertical wall east of the grid point REAL(wp) :: mask_north !< flag to mask vertical wall north of the grid point REAL(wp) :: mask_south !< flag to mask vertical wall south of the grid point REAL(wp) :: mask_west !< flag to mask vertical wall west of the grid point DO k = nzb+1, nzt-1 ! !-- Predetermine flag to mask topography and wall-bounded grid points. flag = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j,i), 3 ) ) mask_east = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j,i+1), 3 ) ) mask_west = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j,i-1), 3 ) ) mask_south = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j-1,i), 3 ) ) mask_north = MERGE( 1.0_wp, 0.0_wp, BTEST( wall_flags_total_0(k,j+1,i), 3 ) ) ! !-- Interpolate eddy diffusivities on staggered gridpoints kmxp = 0.25_wp * ( km(k,j,i)+km(k,j,i+1)+km(k+1,j,i)+km(k+1,j,i+1) ) kmxm = 0.25_wp * ( km(k,j,i)+km(k,j,i-1)+km(k+1,j,i)+km(k+1,j,i-1) ) kmyp = 0.25_wp * ( km(k,j,i)+km(k+1,j,i)+km(k,j+1,i)+km(k+1,j+1,i) ) kmym = 0.25_wp * ( km(k,j,i)+km(k+1,j,i)+km(k,j-1,i)+km(k+1,j-1,i) ) tend(k,j,i) = tend(k,j,i) & + ( mask_east * kmxp * ( & ( w(k,j,i+1) - w(k,j,i) ) * ddx & + ( u(k+1,j,i+1) - u(k,j,i+1) ) * ddzu(k+1) & ) & - mask_west * kmxm * ( & ( w(k,j,i) - w(k,j,i-1) ) * ddx & + ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & ) & ) * ddx * flag & + ( mask_north * kmyp * ( & ( w(k,j+1,i) - w(k,j,i) ) * ddy & + ( v(k+1,j+1,i) - v(k,j+1,i) ) * ddzu(k+1) & ) & - mask_south * kmym * ( & ( w(k,j,i) - w(k,j-1,i) ) * ddy & + ( v(k+1,j,i) - v(k,j,i) ) * ddzu(k+1) & ) & ) * ddy * flag & + 2.0_wp * ( & km(k+1,j,i) * ( w(k+1,j,i) - w(k,j,i) ) * ddzw(k+1) & * rho_air(k+1) & - km(k,j,i) * ( w(k,j,i) - w(k-1,j,i) ) * ddzw(k) & * rho_air(k) & ) * ddzu(k+1) * drho_air_zw(k) * flag ENDDO ! !-- Add horizontal momentum flux v'w' at north- (l=0) and south-facing (l=1) surfaces. Note, in !-- the the flat case, loops won't be entered as start_index > end_index. Furtermore, note, no !-- vertical natural surfaces so far. !-- Default-type surfaces DO l = 0, 1 surf_s = surf_def_v(l)%start_index(j,i) surf_e = surf_def_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_def_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_def_v(l)%mom_flux_w(m) * ddy ENDDO ENDDO ! !-- Natural-type surfaces DO l = 0, 1 surf_s = surf_lsm_v(l)%start_index(j,i) surf_e = surf_lsm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_lsm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_lsm_v(l)%mom_flux_w(m) * ddy ENDDO ENDDO ! !-- Urban-type surfaces DO l = 0, 1 surf_s = surf_usm_v(l)%start_index(j,i) surf_e = surf_usm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_usm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_usm_v(l)%mom_flux_w(m) * ddy ENDDO ENDDO ! !-- Add horizontal momentum flux u'w' at east- (l=2) and west-facing (l=3) surfaces. !-- Default-type surfaces DO l = 2, 3 surf_s = surf_def_v(l)%start_index(j,i) surf_e = surf_def_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_def_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_def_v(l)%mom_flux_w(m) * ddx ENDDO ENDDO ! !-- Natural-type surfaces DO l = 2, 3 surf_s = surf_lsm_v(l)%start_index(j,i) surf_e = surf_lsm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_lsm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_lsm_v(l)%mom_flux_w(m) * ddx ENDDO ENDDO ! !-- Urban-type surfaces DO l = 2, 3 surf_s = surf_usm_v(l)%start_index(j,i) surf_e = surf_usm_v(l)%end_index(j,i) DO m = surf_s, surf_e k = surf_usm_v(l)%k(m) tend(k,j,i) = tend(k,j,i) + surf_usm_v(l)%mom_flux_w(m) * ddx ENDDO ENDDO END SUBROUTINE diffusion_w_ij END MODULE diffusion_w_mod