SUBROUTINE diffusivities( var, var_reference ) !--------------------------------------------------------------------------------! ! This file is part of PALM. ! ! 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 . ! ! Copyright 1997-2014 Leibniz Universitaet Hannover !--------------------------------------------------------------------------------! ! ! Current revisions: ! ----------------- ! ! ! Former revisions: ! ----------------- ! $Id: diffusivities.f90 1310 2014-03-14 08:01:56Z suehring $ ! ! 1179 2013-06-14 05:57:58Z raasch ! use_reference renamed use_single_reference_value ! ! 1036 2012-10-22 13:43:42Z raasch ! code put under GPL (PALM 3.9) ! ! 1015 2012-09-27 09:23:24Z raasch ! OpenACC statements added + code changes required for GPU optimization, ! adjustment of mixing length to the Prandtl mixing length at first grid point ! above ground removed ! ! 667 2010-12-23 12:06:00Z suehring/gryschka ! nxl-1, nxr+1, nys-1, nyn+1 replaced by nxlg, nxrg, nysg, nyng ! ! 137 2007-11-28 08:50:10Z letzel ! Bugfix for summation of sums_l_l for flow_statistics ! Vertical scalar profiles now based on nzb_s_inner and ngp_2dh_s_inner. ! ! 97 2007-06-21 08:23:15Z raasch ! Adjustment of mixing length calculation for the ocean version. ! This is also a bugfix, because the height above the topography is now ! used instead of the height above level k=0. ! theta renamed var, dpt_dz renamed dvar_dz, +new argument var_reference ! use_pt_reference renamed use_reference ! ! 57 2007-03-09 12:05:41Z raasch ! Reference temperature pt_reference can be used in buoyancy term ! ! RCS Log replace by Id keyword, revision history cleaned up ! ! Revision 1.24 2006/04/26 12:16:26 raasch ! OpenMP optimization (+sums_l_l_t), sqrt_e must be private ! ! Revision 1.1 1997/09/19 07:41:10 raasch ! Initial revision ! ! ! Description: ! ------------ ! Computation of the turbulent diffusion coefficients for momentum and heat ! according to Prandtl-Kolmogorov !------------------------------------------------------------------------------! USE arrays_3d USE control_parameters USE grid_variables USE indices USE pegrid USE statistics IMPLICIT NONE INTEGER :: i, j, k, omp_get_thread_num, sr, tn REAL :: dvar_dz, l, ll, l_stable, sqrt_e, var_reference REAL :: var(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ! !-- Default thread number in case of one thread tn = 0 ! !-- Initialization for calculation of the mixing length profile sums_l_l = 0.0 ! !-- Compute the turbulent diffusion coefficient for momentum !$OMP PARALLEL PRIVATE (dvar_dz,i,j,k,l,ll,l_stable,sqrt_e,sr,tn) !$ tn = omp_get_thread_num() ! !-- Data declerations for accelerators !$acc data present( dd2zu, e, km, kh, l_grid, l_wall, nzb_s_inner, rif, var ) !$acc kernels ! !-- Introduce an optional minimum tke IF ( e_min > 0.0 ) THEN !$OMP DO !$acc loop DO i = nxlg, nxrg DO j = nysg, nyng !$acc loop vector( 32 ) DO k = 1, nzt IF ( k > nzb_s_inner(j,i) ) THEN e(k,j,i) = MAX( e(k,j,i), e_min ) ENDIF ENDDO ENDDO ENDDO ENDIF !$OMP DO !$acc loop DO i = nxlg, nxrg DO j = nysg, nyng !$acc loop vector( 32 ) DO k = 1, nzt IF ( k > nzb_s_inner(j,i) ) THEN sqrt_e = SQRT( e(k,j,i) ) ! !-- Determine the mixing length dvar_dz = atmos_ocean_sign * & ! inverse effect of pt/rho gradient ( var(k+1,j,i) - var(k-1,j,i) ) * dd2zu(k) IF ( dvar_dz > 0.0 ) THEN IF ( use_single_reference_value ) THEN l_stable = 0.76 * sqrt_e / & SQRT( g / var_reference * dvar_dz ) + 1E-5 ELSE l_stable = 0.76 * sqrt_e / & SQRT( g / var(k,j,i) * dvar_dz ) + 1E-5 ENDIF ELSE l_stable = l_grid(k) ENDIF ! !-- Adjustment of the mixing length IF ( wall_adjustment ) THEN l = MIN( l_wall(k,j,i), l_grid(k), l_stable ) ll = MIN( l_wall(k,j,i), l_grid(k) ) ELSE l = MIN( l_grid(k), l_stable ) ll = l_grid(k) ENDIF ! !-- Compute diffusion coefficients for momentum and heat km(k,j,i) = 0.1 * l * sqrt_e kh(k,j,i) = ( 1.0 + 2.0 * l / ll ) * km(k,j,i) ENDIF #if ! defined( __openacc ) ! !++ Statistics still have to be realized for accelerators !-- Summation for averaged profile (cf. flow_statistics) DO sr = 0, statistic_regions sums_l_l(k,sr,tn) = sums_l_l(k,sr,tn) + l * rmask(j,i,sr) ENDDO #endif ENDDO ENDDO ENDDO #if ! defined( __openacc ) ! !++ Statistics still have to be realized for accelerators sums_l_l(nzt+1,:,tn) = sums_l_l(nzt,:,tn) ! quasi boundary-condition for ! data output #endif !$OMP END PARALLEL ! !-- Set vertical boundary values (Neumann conditions both at bottom and top). !-- Horizontal boundary conditions at vertical walls are not set because !-- so far vertical walls require usage of a Prandtl-layer where the boundary !-- values of the diffusivities are not needed !$OMP PARALLEL DO !$acc loop DO i = nxlg, nxrg DO j = nysg, nyng km(nzb_s_inner(j,i),j,i) = km(nzb_s_inner(j,i)+1,j,i) km(nzt+1,j,i) = km(nzt,j,i) kh(nzb_s_inner(j,i),j,i) = kh(nzb_s_inner(j,i)+1,j,i) kh(nzt+1,j,i) = kh(nzt,j,i) ENDDO ENDDO ! !-- Set Neumann boundary conditions at the outflow boundaries in case of !-- non-cyclic lateral boundaries IF ( outflow_l ) THEN km(:,:,nxl-1) = km(:,:,nxl) kh(:,:,nxl-1) = kh(:,:,nxl) ENDIF IF ( outflow_r ) THEN km(:,:,nxr+1) = km(:,:,nxr) kh(:,:,nxr+1) = kh(:,:,nxr) ENDIF IF ( outflow_s ) THEN km(:,nys-1,:) = km(:,nys,:) kh(:,nys-1,:) = kh(:,nys,:) ENDIF IF ( outflow_n ) THEN km(:,nyn+1,:) = km(:,nyn,:) kh(:,nyn+1,:) = kh(:,nyn,:) ENDIF !$acc end kernels !$acc end data END SUBROUTINE diffusivities