!> @file lpm.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.f90 2263 2017-06-08 14:59:01Z hellstea $ ! Implemented splitting and merging algorithm ! ! 2233 2017-05-30 18:08:54Z suehring ! ! 2232 2017-05-30 17:47:52Z suehring ! Adjustments to new topography concept ! ! 2000 2016-08-20 18:09:15Z knoop ! Forced header and separation lines into 80 columns ! ! 1936 2016-06-13 13:37:44Z suehring ! Call routine for deallocation of unused memory. ! Formatting adjustments ! ! 1929 2016-06-09 16:25:25Z suehring ! Call wall boundary conditions only if particles are in the vertical range of ! topography. ! ! 1822 2016-04-07 07:49:42Z hoffmann ! Tails removed. ! ! Initialization of sgs model not necessary for the use of cloud_droplets and ! use_sgs_for_particles. ! ! lpm_release_set integrated. ! ! Unused variabled removed. ! ! 1682 2015-10-07 23:56:08Z knoop ! Code annotations made doxygen readable ! ! 1416 2014-06-04 16:04:03Z suehring ! user_lpm_advec is called for each gridpoint. ! Bugfix: in order to prevent an infinite loop, time_loop_done is set .TRUE. ! at the head of the do-loop. ! ! 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 ! ! 1318 2014-03-17 13:35:16Z raasch ! module interfaces removed ! ! 1036 2012-10-22 13:43:42Z raasch ! code put under GPL (PALM 3.9) ! ! 851 2012-03-15 14:32:58Z raasch ! Bugfix: resetting of particle_mask and tail mask moved from routine ! lpm_exchange_horiz to here (end of sub-timestep loop) ! ! 849 2012-03-15 10:35:09Z raasch ! original routine advec_particles split into several subroutines and renamed ! lpm ! ! 831 2012-02-22 00:29:39Z raasch ! thermal_conductivity_l and diff_coeff_l now depend on temperature and ! pressure ! ! 828 2012-02-21 12:00:36Z raasch ! fast hall/wang kernels with fixed radius/dissipation classes added, ! particle feature color renamed class, routine colker renamed ! recalculate_kernel, ! lower limit for droplet radius changed from 1E-7 to 1E-8 ! ! Bugfix: transformation factor for dissipation changed from 1E5 to 1E4 ! ! 825 2012-02-19 03:03:44Z raasch ! droplet growth by condensation may include curvature and solution effects, ! initialisation of temporary particle array for resorting removed, ! particle attributes speed_x|y|z_sgs renamed rvar1|2|3, ! module wang_kernel_mod renamed lpm_collision_kernels_mod, ! wang_collision_kernel renamed wang_kernel ! ! ! Revision 1.1 1999/11/25 16:16:06 raasch ! Initial revision ! ! ! Description: ! ------------ !> Particle advection !------------------------------------------------------------------------------! SUBROUTINE lpm USE arrays_3d, & ONLY: ql_c, ql_v, ql_vp USE control_parameters, & ONLY: cloud_droplets, dt_3d, dt_3d_reached, dt_3d_reached_l, & molecular_viscosity, simulated_time, topography USE cpulog, & ONLY: cpu_log, log_point, log_point_s USE indices, & ONLY: nxl, nxr, nys, nyn, nzb, nzb_max, nzt USE kinds USE lpm_exchange_horiz_mod, & ONLY: dealloc_particles_array, lpm_exchange_horiz, lpm_move_particle USE lpm_init_mod, & ONLY: lpm_create_particle, PHASE_RELEASE USE lpm_pack_arrays_mod, & ONLY: lpm_pack_all_arrays USE particle_attributes, & ONLY: collision_kernel, deleted_particles, deallocate_memory, & dt_write_particle_data, dt_prel, end_time_prel, & grid_particles, merging, number_of_particles, & number_of_particle_groups, particles, particle_groups, & prt_count, splitting, step_dealloc, time_prel, & time_write_particle_data, trlp_count_sum, trlp_count_recv_sum, & trnp_count_sum, trnp_count_recv_sum, trrp_count_sum, & trrp_count_recv_sum, trsp_count_sum, trsp_count_recv_sum, & use_sgs_for_particles, write_particle_statistics USE pegrid IMPLICIT NONE INTEGER(iwp) :: i !< INTEGER(iwp) :: ie !< INTEGER(iwp) :: is !< INTEGER(iwp) :: j !< INTEGER(iwp) :: je !< INTEGER(iwp) :: js !< INTEGER(iwp), SAVE :: lpm_count = 0 !< INTEGER(iwp) :: k !< INTEGER(iwp) :: ke !< INTEGER(iwp) :: ks !< INTEGER(iwp) :: m !< INTEGER(iwp), SAVE :: steps = 0 !< LOGICAL :: first_loop_stride !< CALL cpu_log( log_point(25), 'lpm', 'start' ) ! !-- Write particle data at current time on file. !-- This has to be done here, before particles are further processed, !-- because they may be deleted within this timestep (in case that !-- dt_write_particle_data = dt_prel = particle_maximum_age). time_write_particle_data = time_write_particle_data + dt_3d IF ( time_write_particle_data >= dt_write_particle_data ) THEN CALL lpm_data_output_particles ! !-- The MOD function allows for changes in the output interval with restart !-- runs. time_write_particle_data = MOD( time_write_particle_data, & MAX( dt_write_particle_data, dt_3d ) ) ENDIF ! !-- Initialize arrays for marking those particles to be deleted after the !-- (sub-) timestep deleted_particles = 0 ! !-- Initialize variables used for accumulating the number of particles !-- exchanged between the subdomains during all sub-timesteps (if sgs !-- velocities are included). These data are output further below on the !-- particle statistics file. trlp_count_sum = 0 trlp_count_recv_sum = 0 trrp_count_sum = 0 trrp_count_recv_sum = 0 trsp_count_sum = 0 trsp_count_recv_sum = 0 trnp_count_sum = 0 trnp_count_recv_sum = 0 ! !-- Calculate exponential term used in case of particle inertia for each !-- of the particle groups DO m = 1, number_of_particle_groups IF ( particle_groups(m)%density_ratio /= 0.0_wp ) THEN particle_groups(m)%exp_arg = & 4.5_wp * particle_groups(m)%density_ratio * & molecular_viscosity / ( particle_groups(m)%radius )**2 particle_groups(m)%exp_term = EXP( -particle_groups(m)%exp_arg * & dt_3d ) ENDIF ENDDO ! !-- If necessary, release new set of particles IF ( time_prel >= dt_prel .AND. end_time_prel > simulated_time ) THEN CALL lpm_create_particle(PHASE_RELEASE) ! !-- The MOD function allows for changes in the output interval with !-- restart runs. time_prel = MOD( time_prel, MAX( dt_prel, dt_3d ) ) ENDIF ! !-- Reset summation arrays IF ( cloud_droplets) THEN ql_c = 0.0_wp ql_v = 0.0_wp ql_vp = 0.0_wp ENDIF first_loop_stride = .TRUE. grid_particles(:,:,:)%time_loop_done = .TRUE. ! !-- Timestep loop for particle advection. !-- This loop has to be repeated until the advection time of every particle !-- (within the total domain!) has reached the LES timestep (dt_3d). !-- In case of including the SGS velocities, the particle timestep may be !-- smaller than the LES timestep (because of the Lagrangian timescale !-- restriction) and particles may require to undergo several particle !-- timesteps, before the LES timestep is reached. Because the number of these !-- particle timesteps to be carried out is unknown at first, these steps are !-- carried out in the following infinite loop with exit condition. DO CALL cpu_log( log_point_s(44), 'lpm_advec', 'start' ) CALL cpu_log( log_point_s(44), 'lpm_advec', 'pause' ) grid_particles(:,:,:)%time_loop_done = .TRUE. ! !-- If particle advection includes SGS velocity components, calculate the !-- required SGS quantities (i.e. gradients of the TKE, as well as !-- horizontally averaged profiles of the SGS TKE and the resolved-scale !-- velocity variances) IF ( use_sgs_for_particles .AND. .NOT. cloud_droplets ) THEN CALL lpm_init_sgs_tke ENDIF DO i = nxl, nxr DO j = nys, nyn DO k = nzb+1, nzt number_of_particles = prt_count(k,j,i) ! !-- If grid cell gets empty, flag must be true IF ( number_of_particles <= 0 ) THEN grid_particles(k,j,i)%time_loop_done = .TRUE. CYCLE ENDIF IF ( .NOT. first_loop_stride .AND. & grid_particles(k,j,i)%time_loop_done ) CYCLE particles => grid_particles(k,j,i)%particles(1:number_of_particles) particles(1:number_of_particles)%particle_mask = .TRUE. ! !-- Initialize the variable storing the total time that a particle !-- has advanced within the timestep procedure IF ( first_loop_stride ) THEN particles(1:number_of_particles)%dt_sum = 0.0_wp ENDIF ! !-- Particle (droplet) growth by condensation/evaporation and !-- collision IF ( cloud_droplets .AND. first_loop_stride) THEN ! !-- Droplet growth by condensation / evaporation CALL lpm_droplet_condensation(i,j,k) ! !-- Particle growth by collision IF ( collision_kernel /= 'none' ) THEN CALL lpm_droplet_collision(i,j,k) ENDIF ENDIF ! !-- Initialize the switch used for the loop exit condition checked !-- at the end of this loop. If at least one particle has failed to !-- reach the LES timestep, this switch will be set false in !-- lpm_advec. dt_3d_reached_l = .TRUE. ! !-- Particle advection CALL lpm_advec(i,j,k) ! !-- Particle reflection from walls. Only applied if the particles !-- are in the vertical range of the topography. (Here, some !-- optimization is still possible.) IF ( topography /= 'flat' .AND. k < nzb_max + 2 ) THEN CALL lpm_boundary_conds( 'walls' ) ENDIF ! !-- User-defined actions after the calculation of the new particle !-- position CALL user_lpm_advec(i,j,k) ! !-- Apply boundary conditions to those particles that have crossed !-- the top or bottom boundary and delete those particles, which are !-- older than allowed CALL lpm_boundary_conds( 'bottom/top' ) ! !--- If not all particles of the actual grid cell have reached the !-- LES timestep, this cell has to to another loop iteration. Due to !-- the fact that particles can move into neighboring grid cell, !-- these neighbor cells also have to perform another loop iteration IF ( .NOT. dt_3d_reached_l ) THEN ks = MAX(nzb+1,k) ke = MIN(nzt,k) js = MAX(nys,j) je = MIN(nyn,j) is = MAX(nxl,i) ie = MIN(nxr,i) grid_particles(ks:ke,js:je,is:ie)%time_loop_done = .FALSE. ENDIF ENDDO ENDDO ENDDO steps = steps + 1 dt_3d_reached_l = ALL(grid_particles(:,:,:)%time_loop_done) ! !-- Find out, if all particles on every PE have completed the LES timestep !-- and set the switch corespondingly #if defined( __parallel ) IF ( collective_wait ) CALL MPI_BARRIER( comm2d, ierr ) CALL MPI_ALLREDUCE( dt_3d_reached_l, dt_3d_reached, 1, MPI_LOGICAL, & MPI_LAND, comm2d, ierr ) #else dt_3d_reached = dt_3d_reached_l #endif CALL cpu_log( log_point_s(44), 'lpm_advec', 'stop' ) ! !-- Increment time since last release IF ( dt_3d_reached ) time_prel = time_prel + dt_3d ! !-- Apply splitting and merging algorithm IF ( cloud_droplets ) THEN IF ( splitting ) THEN CALL lpm_splitting ENDIF IF ( merging ) THEN CALL lpm_merging ENDIF ENDIF ! !-- Move Particles local to PE to a different grid cell CALL lpm_move_particle ! !-- Horizontal boundary conditions including exchange between subdmains CALL lpm_exchange_horiz ! !-- Pack particles (eliminate those marked for deletion), !-- determine new number of particles CALL lpm_pack_all_arrays ! !-- Initialize variables for the next (sub-) timestep, i.e., for marking !-- those particles to be deleted after the timestep deleted_particles = 0 IF ( dt_3d_reached ) EXIT first_loop_stride = .FALSE. ENDDO ! timestep loop ! !-- Calculate the new liquid water content for each grid box IF ( cloud_droplets ) CALL lpm_calc_liquid_water_content ! !-- Deallocate unused memory IF ( deallocate_memory .AND. lpm_count == step_dealloc ) THEN CALL dealloc_particles_array lpm_count = 0 ELSEIF ( deallocate_memory ) THEN lpm_count = lpm_count + 1 ENDIF ! !-- Set particle attributes. !-- Feature is not available if collision is activated, because the respective !-- particle attribute (class) is then used for storing the particle radius !-- class. IF ( collision_kernel == 'none' ) CALL lpm_set_attributes ! !-- Set particle attributes defined by the user CALL user_lpm_set_attributes ! !-- Write particle statistics (in particular the number of particles !-- exchanged between the subdomains) on file IF ( write_particle_statistics ) CALL lpm_write_exchange_statistics CALL cpu_log( log_point(25), 'lpm', 'stop' ) END SUBROUTINE lpm