!> @file lpm_boundary_conds.f90 !------------------------------------------------------------------------------! ! 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 1997-2017 Leibniz Universitaet Hannover !------------------------------------------------------------------------------! ! ! Current revisions: ! ----------------- ! ! ! Former revisions: ! ----------------- ! $Id: lpm_boundary_conds.f90 2318 2017-07-20 17:27:44Z Giersch $ ! Get topography top index via Function call ! ! 2317 2017-07-20 17:27:19Z suehring ! ! 2232 2017-05-30 17:47:52Z suehring ! Adjustments to new topography and surface concept ! Rename character range into location, as range is an intrinsic. ! ! 2000 2016-08-20 18:09:15Z knoop ! Forced header and separation lines into 80 columns ! ! 1929 2016-06-09 16:25:25Z suehring ! Rewritten wall reflection ! ! 1822 2016-04-07 07:49:42Z hoffmann ! Tails removed. Unused variables removed. ! ! 1682 2015-10-07 23:56:08Z knoop ! Code annotations made doxygen readable ! ! 1359 2014-04-11 17:15:14Z hoffmann ! New particle structure integrated. ! Kind definition added to all floating point numbers. ! ! 1320 2014-03-20 08:40:49Z raasch ! ONLY-attribute added to USE-statements, ! kind-parameters added to all INTEGER and REAL declaration statements, ! kinds are defined in new module kinds, ! revision history before 2012 removed, ! comment fields (!:) to be used for variable explanations added to ! all variable declaration statements ! ! 1036 2012-10-22 13:43:42Z raasch ! code put under GPL (PALM 3.9) ! ! 849 2012-03-15 10:35:09Z raasch ! routine renamed lpm_boundary_conds, bottom and top boundary conditions ! included (former part of advec_particles) ! ! 824 2012-02-17 09:09:57Z raasch ! particle attributes speed_x|y|z_sgs renamed rvar1|2|3 ! ! Initial version (2007/03/09) ! ! Description: ! ------------ !> Boundary conditions for the Lagrangian particles. !> The routine consists of two different parts. One handles the bottom (flat) !> and top boundary. In this part, also particles which exceeded their lifetime !> are deleted. !> The other part handles the reflection of particles from vertical walls. !> This part was developed by Jin Zhang during 2006-2007. !> !> To do: Code structure for finding the t_index values and for checking the !> ----- reflection conditions is basically the same for all four cases, so it !> should be possible to further simplify/shorten it. !> !> THE WALLS PART OF THIS ROUTINE HAS NOT BEEN TESTED FOR OCEAN RUNS SO FAR!!!! !> (see offset_ocean_*) !------------------------------------------------------------------------------! SUBROUTINE lpm_boundary_conds( location ) USE arrays_3d, & ONLY: zu, zw USE control_parameters, & ONLY: dz, message_string, particle_maximum_age USE cpulog, & ONLY: cpu_log, log_point_s USE grid_variables, & ONLY: ddx, dx, ddy, dy USE indices, & ONLY: nxl, nxr, nyn, nys, nz, nzb USE kinds USE particle_attributes, & ONLY: deleted_particles, ibc_par_b, ibc_par_t, number_of_particles, & particles, particle_type, offset_ocean_nzt_m1, & use_sgs_for_particles USE pegrid USE surface_mod, & ONLY: get_topography_top_index IMPLICIT NONE CHARACTER (LEN=*) :: location !< INTEGER(iwp) :: inc !< dummy for sorting algorithmus INTEGER(iwp) :: ir !< dummy for sorting algorithmus INTEGER(iwp) :: i1 !< grid index (x) of old particle position INTEGER(iwp) :: i2 !< grid index (x) of current particle position INTEGER(iwp) :: i3 !< grid index (x) of intermediate particle position INTEGER(iwp) :: jr !< dummy for sorting algorithmus INTEGER(iwp) :: j1 !< grid index (y) of old particle position INTEGER(iwp) :: j2 !< grid index (x) of current particle position INTEGER(iwp) :: j3 !< grid index (x) of intermediate particle position INTEGER(iwp) :: k_wall !< vertical index of topography top INTEGER(iwp) :: n !< particle number INTEGER(iwp) :: t_index !< running index for intermediate particle timesteps in reflection algorithmus INTEGER(iwp) :: t_index_number !< number of intermediate particle timesteps in reflection algorithmus INTEGER(iwp) :: tmp_x !< dummy for sorting algorithmus INTEGER(iwp) :: tmp_y !< dummy for sorting algorithmus INTEGER(iwp), DIMENSION(0:10) :: x_ind(0:10) = 0 !< index array (x) of intermediate particle positions INTEGER(iwp), DIMENSION(0:10) :: y_ind(0:10) = 0 !< index array (x) of intermediate particle positions LOGICAL :: cross_wall_x !< flag to check if particle reflection along x is necessary LOGICAL :: cross_wall_y !< flag to check if particle reflection along y is necessary LOGICAL :: downwards !< flag to check if particle reflection along z is necessary (only if particle move downwards) LOGICAL :: reflect_x !< flag to check if particle is already reflected along x LOGICAL :: reflect_y !< flag to check if particle is already reflected along y LOGICAL :: reflect_z !< flag to check if particle is already reflected along z LOGICAL :: tmp_reach_x !< dummy for sorting algorithmus LOGICAL :: tmp_reach_y !< dummy for sorting algorithmus LOGICAL :: tmp_reach_z !< dummy for sorting algorithmus LOGICAL :: x_wall_reached !< flag to check if particle has already reached wall LOGICAL :: y_wall_reached !< flag to check if particle has already reached wall LOGICAL, DIMENSION(0:10) :: reach_x !< flag to check if particle is at a yz-wall LOGICAL, DIMENSION(0:10) :: reach_y !< flag to check if particle is at a xz-wall LOGICAL, DIMENSION(0:10) :: reach_z !< flag to check if particle is at a xy-wall REAL(wp) :: dt_particle !< particle timestep REAL(wp) :: dum !< dummy argument REAL(wp) :: eps = 1E-10_wp !< security number to check if particle has reached a wall REAL(wp) :: pos_x !< intermediate particle position (x) REAL(wp) :: pos_x_old !< particle position (x) at previous particle timestep REAL(wp) :: pos_y !< intermediate particle position (y) REAL(wp) :: pos_y_old !< particle position (y) at previous particle timestep REAL(wp) :: pos_z !< intermediate particle position (z) REAL(wp) :: pos_z_old !< particle position (z) at previous particle timestep REAL(wp) :: prt_x !< current particle position (x) REAL(wp) :: prt_y !< current particle position (y) REAL(wp) :: prt_z !< current particle position (z) REAL(wp) :: t_old !< previous reflection time REAL(wp) :: tmp_t !< dummy for sorting algorithmus REAL(wp) :: xwall !< location of wall in x REAL(wp) :: ywall !< location of wall in y REAL(wp) :: zwall1 !< location of wall in z (old grid box) REAL(wp) :: zwall2 !< location of wall in z (current grid box) REAL(wp) :: zwall3 !< location of wall in z (old y, current x) REAL(wp) :: zwall4 !< location of wall in z (current y, old x) REAL(wp), DIMENSION(0:10) :: t !< reflection time IF ( location == 'bottom/top' ) THEN ! !-- Apply boundary conditions to those particles that have crossed the top or !-- bottom boundary and delete those particles, which are older than allowed DO n = 1, number_of_particles ! !-- Stop if particles have moved further than the length of one !-- PE subdomain (newly released particles have age = age_m!) IF ( particles(n)%age /= particles(n)%age_m ) THEN IF ( ABS(particles(n)%speed_x) > & ((nxr-nxl+2)*dx)/(particles(n)%age-particles(n)%age_m) .OR. & ABS(particles(n)%speed_y) > & ((nyn-nys+2)*dy)/(particles(n)%age-particles(n)%age_m) ) THEN WRITE( message_string, * ) 'particle too fast. n = ', n CALL message( 'lpm_boundary_conds', 'PA0148', 2, 2, -1, 6, 1 ) ENDIF ENDIF IF ( particles(n)%age > particle_maximum_age .AND. & particles(n)%particle_mask ) & THEN particles(n)%particle_mask = .FALSE. deleted_particles = deleted_particles + 1 ENDIF IF ( particles(n)%z >= zu(nz) .AND. particles(n)%particle_mask ) THEN IF ( ibc_par_t == 1 ) THEN ! !-- Particle absorption particles(n)%particle_mask = .FALSE. deleted_particles = deleted_particles + 1 ELSEIF ( ibc_par_t == 2 ) THEN ! !-- Particle reflection particles(n)%z = 2.0_wp * zu(nz) - particles(n)%z particles(n)%speed_z = -particles(n)%speed_z IF ( use_sgs_for_particles .AND. & particles(n)%rvar3 > 0.0_wp ) THEN particles(n)%rvar3 = -particles(n)%rvar3 ENDIF ENDIF ENDIF IF ( particles(n)%z < zw(0) .AND. particles(n)%particle_mask ) THEN IF ( ibc_par_b == 1 ) THEN ! !-- Particle absorption particles(n)%particle_mask = .FALSE. deleted_particles = deleted_particles + 1 ELSEIF ( ibc_par_b == 2 ) THEN ! !-- Particle reflection particles(n)%z = 2.0_wp * zw(0) - particles(n)%z particles(n)%speed_z = -particles(n)%speed_z IF ( use_sgs_for_particles .AND. & particles(n)%rvar3 < 0.0_wp ) THEN particles(n)%rvar3 = -particles(n)%rvar3 ENDIF ENDIF ENDIF ENDDO ELSEIF ( location == 'walls' ) THEN CALL cpu_log( log_point_s(48), 'lpm_wall_reflect', 'start' ) DO n = 1, number_of_particles ! !-- Recalculate particle timestep dt_particle = particles(n)%age - particles(n)%age_m ! !-- Obtain x/y indices for current particle position i2 = ( particles(n)%x + 0.5_wp * dx ) * ddx j2 = ( particles(n)%y + 0.5_wp * dy ) * ddy ! !-- Save current particle positions prt_x = particles(n)%x prt_y = particles(n)%y prt_z = particles(n)%z ! !-- Recalculate old particle positions pos_x_old = particles(n)%x - particles(n)%speed_x * dt_particle pos_y_old = particles(n)%y - particles(n)%speed_y * dt_particle pos_z_old = particles(n)%z - particles(n)%speed_z * dt_particle ! !-- Obtain x/y indices for old particle positions i1 = ( pos_x_old + 0.5_wp * dx ) * ddx j1 = ( pos_y_old + 0.5_wp * dy ) * ddy ! !-- Determine horizontal as well as vertical walls at which particle can !-- be potentially reflected. !-- Start with walls aligned in yz layer. !-- Wall to the right IF ( prt_x > pos_x_old ) THEN xwall = ( i1 + 0.5_wp ) * dx ! !-- Wall to the left ELSE xwall = ( i1 - 0.5_wp ) * dx ENDIF ! !-- Walls aligned in xz layer !-- Wall to the north IF ( prt_y > pos_y_old ) THEN ywall = ( j1 + 0.5_wp ) * dy !-- Wall to the south ELSE ywall = ( j1 - 0.5_wp ) * dy ENDIF ! !-- Walls aligned in xy layer at which particle can be possiblly reflected. !-- The construct of MERGE and BTEST is used to determine the topography- !-- top index (former nzb_s_inner). zwall1 = zw( get_topography_top_index( j2, i2, 's' ) ) zwall2 = zw( get_topography_top_index( j1, i1, 's' ) ) zwall3 = zw( get_topography_top_index( j1, i2, 's' ) ) zwall4 = zw( get_topography_top_index( j2, i1, 's' ) ) ! !-- Initialize flags to check if particle reflection is necessary downwards = .FALSE. cross_wall_x = .FALSE. cross_wall_y = .FALSE. ! !-- Initialize flags to check if a wall is reached reach_x = .FALSE. reach_y = .FALSE. reach_z = .FALSE. ! !-- Initialize flags to check if a particle was already reflected reflect_x = .FALSE. reflect_y = .FALSE. reflect_z = .FALSE. ! !-- Initialize flags to check if a vertical wall is already crossed. !-- ( Required to obtain correct indices. ) x_wall_reached = .FALSE. y_wall_reached = .FALSE. ! !-- Initialize time array t = 0.0_wp ! !-- Check if particle can reach any wall. This case, calculate the !-- fractional time needed to reach this wall. Store this fractional !-- timestep in array t. Moreover, store indices for these grid !-- boxes where the respective wall belongs to. !-- Start with x-direction. t_index = 1 t(t_index) = ( xwall - pos_x_old ) & / MERGE( MAX( prt_x - pos_x_old, 1E-30_wp ), & MIN( prt_x - pos_x_old, -1E-30_wp ), & prt_x > pos_x_old ) x_ind(t_index) = i2 y_ind(t_index) = j1 reach_x(t_index) = .TRUE. reach_y(t_index) = .FALSE. reach_z(t_index) = .FALSE. ! !-- Store these values only if particle really reaches any wall. t must !-- be in a interval between [0:1]. IF ( t(t_index) <= 1.0_wp .AND. t(t_index) >= 0.0_wp ) THEN t_index = t_index + 1 cross_wall_x = .TRUE. ENDIF ! !-- y-direction t(t_index) = ( ywall - pos_y_old ) & / MERGE( MAX( prt_y - pos_y_old, 1E-30_wp ), & MIN( prt_y - pos_y_old, -1E-30_wp ), & prt_y > pos_y_old ) x_ind(t_index) = i1 y_ind(t_index) = j2 reach_x(t_index) = .FALSE. reach_y(t_index) = .TRUE. reach_z(t_index) = .FALSE. IF ( t(t_index) <= 1.0_wp .AND. t(t_index) >= 0.0_wp ) THEN t_index = t_index + 1 cross_wall_y = .TRUE. ENDIF ! !-- z-direction !-- At first, check if particle moves downwards. Only in this case a !-- particle can be reflected vertically. IF ( prt_z < pos_z_old ) THEN downwards = .TRUE. dum = 1.0_wp / MERGE( MAX( prt_z - pos_z_old, 1E-30_wp ), & MIN( prt_z - pos_z_old, -1E-30_wp ), & prt_z > pos_z_old ) t(t_index) = ( zwall1 - pos_z_old ) * dum x_ind(t_index) = i2 y_ind(t_index) = j2 reach_x(t_index) = .FALSE. reach_y(t_index) = .FALSE. reach_z(t_index) = .TRUE. IF ( t(t_index) <= 1.0_wp .AND. t(t_index) >= 0.0_wp ) & t_index = t_index + 1 reach_x(t_index) = .FALSE. reach_y(t_index) = .FALSE. reach_z(t_index) = .TRUE. t(t_index) = ( zwall2 - pos_z_old ) * dum x_ind(t_index) = i1 y_ind(t_index) = j1 IF ( t(t_index) <= 1.0_wp .AND. t(t_index) >= 0.0_wp ) & t_index = t_index + 1 reach_x(t_index) = .FALSE. reach_y(t_index) = .FALSE. reach_z(t_index) = .TRUE. t(t_index) = ( zwall3 - pos_z_old ) * dum x_ind(t_index) = i2 y_ind(t_index) = j1 IF ( t(t_index) <= 1.0_wp .AND. t(t_index) >= 0.0_wp ) & t_index = t_index + 1 reach_x(t_index) = .FALSE. reach_y(t_index) = .FALSE. reach_z(t_index) = .TRUE. t(t_index) = ( zwall4 - pos_z_old ) * dum x_ind(t_index) = i1 y_ind(t_index) = j2 IF ( t(t_index) <= 1.0_wp .AND. t(t_index) >= 0.0_wp ) & t_index = t_index + 1 END IF t_index_number = t_index - 1 ! !-- Carry out reflection only if particle reaches any wall IF ( cross_wall_x .OR. cross_wall_y .OR. downwards ) THEN ! !-- Sort fractional timesteps in ascending order. Also sort the !-- corresponding indices and flag according to the time interval a !-- particle reaches the respective wall. inc = 1 jr = 1 DO WHILE ( inc <= t_index_number ) inc = 3 * inc + 1 ENDDO DO WHILE ( inc > 1 ) inc = inc / 3 DO ir = inc+1, t_index_number tmp_t = t(ir) tmp_x = x_ind(ir) tmp_y = y_ind(ir) tmp_reach_x = reach_x(ir) tmp_reach_y = reach_y(ir) tmp_reach_z = reach_z(ir) jr = ir DO WHILE ( t(jr-inc) > tmp_t ) t(jr) = t(jr-inc) x_ind(jr) = x_ind(jr-inc) y_ind(jr) = y_ind(jr-inc) reach_x(jr) = reach_x(jr-inc) reach_y(jr) = reach_y(jr-inc) reach_z(jr) = reach_z(jr-inc) jr = jr - inc IF ( jr <= inc ) EXIT ENDDO t(jr) = tmp_t x_ind(jr) = tmp_x y_ind(jr) = tmp_y reach_x(jr) = tmp_reach_x reach_y(jr) = tmp_reach_y reach_z(jr) = tmp_reach_z ENDDO ENDDO ! !-- Initialize temporary particle positions pos_x = pos_x_old pos_y = pos_y_old pos_z = pos_z_old ! !-- Loop over all times a particle possibly moves into a new grid box t_old = 0.0_wp DO t_index = 1, t_index_number ! !-- Calculate intermediate particle position according to the !-- timesteps a particle reaches any wall. pos_x = pos_x + ( t(t_index) - t_old ) * dt_particle & * particles(n)%speed_x pos_y = pos_y + ( t(t_index) - t_old ) * dt_particle & * particles(n)%speed_y pos_z = pos_z + ( t(t_index) - t_old ) * dt_particle & * particles(n)%speed_z ! !-- Obtain x/y grid indices for intermediate particle position from !-- sorted index array i3 = x_ind(t_index) j3 = y_ind(t_index) ! !-- Check which wall is already reached IF ( .NOT. x_wall_reached ) x_wall_reached = reach_x(t_index) IF ( .NOT. y_wall_reached ) y_wall_reached = reach_y(t_index) ! !-- Check if a particle needs to be reflected at any yz-wall. If !-- necessary, carry out reflection. Please note, a security !-- constant is required, as the particle position do not !-- necessarily exactly match the wall location due to rounding !-- errors. At first, determine index of topography top at (j3,i3) k_wall = get_topography_top_index( j3, i3, 's' ) IF ( ABS( pos_x - xwall ) < eps .AND. & pos_z <= zw(k_wall) .AND. & reach_x(t_index) .AND. & .NOT. reflect_x ) THEN ! !-- Reflection in x-direction. !-- Ensure correct reflection by MIN/MAX functions, depending on !-- direction of particle transport. !-- Due to rounding errors pos_x do not exactly matches the wall !-- location, leading to erroneous reflection. pos_x = MERGE( MIN( 2.0_wp * xwall - pos_x, xwall ), & MAX( 2.0_wp * xwall - pos_x, xwall ), & particles(n)%x > xwall ) ! !-- Change sign of particle speed particles(n)%speed_x = - particles(n)%speed_x ! !-- Change also sign of subgrid-scale particle speed particles(n)%rvar1 = - particles(n)%rvar1 ! !-- Set flag that reflection along x is already done reflect_x = .TRUE. ! !-- As particle do not crosses any further yz-wall during !-- this timestep, set further x-indices to the current one. x_ind(t_index:t_index_number) = i1 ! !-- If particle already reached the wall but was not reflected, !-- set further x-indices to the new one. ELSEIF ( x_wall_reached .AND. .NOT. reflect_x ) THEN x_ind(t_index:t_index_number) = i2 ENDIF ! !-- Check if a particle needs to be reflected at any xz-wall. If !-- necessary, carry out reflection. At first, determine index of !-- topography top at (j3,i3) k_wall = get_topography_top_index( j3, i3, 's' ) IF ( ABS( pos_y - ywall ) < eps .AND. & pos_z <= zw(k_wall) .AND. & reach_y(t_index) .AND. & .NOT. reflect_y ) THEN pos_y = MERGE( MIN( 2.0_wp * ywall - pos_y, ywall ), & MAX( 2.0_wp * ywall - pos_y, ywall ), & particles(n)%y > ywall ) particles(n)%speed_y = - particles(n)%speed_y particles(n)%rvar2 = - particles(n)%rvar2 reflect_y = .TRUE. y_ind(t_index:t_index_number) = j1 ELSEIF ( y_wall_reached .AND. .NOT. reflect_y ) THEN y_ind(t_index:t_index_number) = j2 ENDIF ! !-- Check if a particle needs to be reflected at any xy-wall. If !-- necessary, carry out reflection. IF ( downwards .AND. reach_z(t_index) .AND. & .NOT. reflect_z ) THEN ! !-- Determine index of topography top at (j3,i3) and chick if !-- particle is below. k_wall = get_topography_top_index( j3, i3, 's' ) IF ( pos_z - zw(k_wall) < eps ) THEN pos_z = MAX( 2.0_wp * zw(k_wall) - pos_z, & zw(k_wall) ) particles(n)%speed_z = - particles(n)%speed_z particles(n)%rvar3 = - particles(n)%rvar3 reflect_z = .TRUE. ENDIF ENDIF ! !-- Swap time t_old = t(t_index) ENDDO ! !-- If a particle was reflected, calculate final position from last !-- intermediate position. IF ( reflect_x .OR. reflect_y .OR. reflect_z ) THEN particles(n)%x = pos_x + ( 1.0_wp - t_old ) * dt_particle & * particles(n)%speed_x particles(n)%y = pos_y + ( 1.0_wp - t_old ) * dt_particle & * particles(n)%speed_y particles(n)%z = pos_z + ( 1.0_wp - t_old ) * dt_particle & * particles(n)%speed_z ENDIF ENDIF ENDDO CALL cpu_log( log_point_s(48), 'lpm_wall_reflect', 'stop' ) ENDIF END SUBROUTINE lpm_boundary_conds