source: palm/trunk/SOURCE/lpm.f90 @ 1036

Last change on this file since 1036 was 1036, checked in by raasch, 9 years ago

code has been put under the GNU General Public License (v3)

  • Property svn:keywords set to Id
File size: 9.7 KB
Line 
1 SUBROUTINE lpm
2
3!--------------------------------------------------------------------------------!
4! This file is part of PALM.
5!
6! PALM is free software: you can redistribute it and/or modify it under the terms
7! of the GNU General Public License as published by the Free Software Foundation,
8! either version 3 of the License, or (at your option) any later version.
9!
10! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
11! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12! A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
13!
14! You should have received a copy of the GNU General Public License along with
15! PALM. If not, see <http://www.gnu.org/licenses/>.
16!
17! Copyright 1997-2012  Leibniz University Hannover
18!--------------------------------------------------------------------------------!
19!
20! Current revisions:
21! ------------------
22!
23!
24! Former revisions:
25! -----------------
26! $Id: lpm.f90 1036 2012-10-22 13:43:42Z raasch $
27!
28! 851 2012-03-15 14:32:58Z raasch
29! Bugfix: resetting of particle_mask and tail mask moved from routine
30! lpm_exchange_horiz to here (end of sub-timestep loop)
31!
32! 849 2012-03-15 10:35:09Z raasch
33! original routine advec_particles split into several subroutines and renamed
34! lpm
35!
36! 831 2012-02-22 00:29:39Z raasch
37! thermal_conductivity_l and diff_coeff_l now depend on temperature and
38! pressure
39!
40! 828 2012-02-21 12:00:36Z raasch
41! fast hall/wang kernels with fixed radius/dissipation classes added,
42! particle feature color renamed class, routine colker renamed
43! recalculate_kernel,
44! lower limit for droplet radius changed from 1E-7 to 1E-8
45!
46! Bugfix: transformation factor for dissipation changed from 1E5 to 1E4
47!
48! 825 2012-02-19 03:03:44Z raasch
49! droplet growth by condensation may include curvature and solution effects,
50! initialisation of temporary particle array for resorting removed,
51! particle attributes speed_x|y|z_sgs renamed rvar1|2|3,
52! module wang_kernel_mod renamed lpm_collision_kernels_mod,
53! wang_collision_kernel renamed wang_kernel
54!
55! 799 2011-12-21 17:48:03Z franke
56! Implementation of Wang collision kernel and corresponding new parameter
57! wang_collision_kernel
58!
59! 792 2011-12-01 raasch
60! particle arrays (particles, particles_temp) implemented as pointers in
61! order to speed up sorting (see routine sort_particles)
62!
63! 759 2011-09-15 13:58:31Z raasch
64! Splitting of parallel I/O (routine write_particles)
65!
66! Revision 1.1  1999/11/25 16:16:06  raasch
67! Initial revision
68!
69!
70! Description:
71! ------------
72! Particle advection
73!------------------------------------------------------------------------------!
74
75    USE arrays_3d
76    USE control_parameters
77    USE cpulog
78    USE interfaces
79    USE particle_attributes
80    USE pegrid
81    USE statistics
82
83    IMPLICIT NONE
84
85    INTEGER ::  m
86
87
88    CALL cpu_log( log_point(25), 'lpm', 'start' )
89
90!
91!-- Write particle data at current time on file.
92!-- This has to be done here, before particles are further processed,
93!-- because they may be deleted within this timestep (in case that
94!-- dt_write_particle_data = dt_prel = particle_maximum_age).
95    time_write_particle_data = time_write_particle_data + dt_3d
96    IF ( time_write_particle_data >= dt_write_particle_data )  THEN
97
98       CALL lpm_data_output_particles
99!
100!--    The MOD function allows for changes in the output interval with restart
101!--    runs.
102       time_write_particle_data = MOD( time_write_particle_data, &
103                                  MAX( dt_write_particle_data, dt_3d ) )
104    ENDIF
105
106
107!
108!-- Initialize arrays for marking those particles/tails to be deleted after the
109!-- (sub-) timestep
110    particle_mask     = .TRUE.
111    deleted_particles = 0
112
113    IF ( use_particle_tails )  THEN
114       tail_mask = .TRUE.
115    ENDIF
116    deleted_tails = 0
117
118
119!
120!-- Initialize variables used for accumulating the number of particles
121!-- exchanged between the subdomains during all sub-timesteps (if sgs
122!-- velocities are included). These data are output further below on the
123!-- particle statistics file.
124    trlp_count_sum      = 0
125    trlp_count_recv_sum = 0
126    trrp_count_sum      = 0
127    trrp_count_recv_sum = 0
128    trsp_count_sum      = 0
129    trsp_count_recv_sum = 0
130    trnp_count_sum      = 0
131    trnp_count_recv_sum = 0
132
133
134!
135!-- Calculate exponential term used in case of particle inertia for each
136!-- of the particle groups
137    DO  m = 1, number_of_particle_groups
138       IF ( particle_groups(m)%density_ratio /= 0.0 )  THEN
139          particle_groups(m)%exp_arg  =                                        &
140                    4.5 * particle_groups(m)%density_ratio *                   &
141                    molecular_viscosity / ( particle_groups(m)%radius )**2
142          particle_groups(m)%exp_term = EXP( -particle_groups(m)%exp_arg * &
143                                             dt_3d )
144       ENDIF
145    ENDDO
146
147
148!
149!-- Particle (droplet) growth by condensation/evaporation and collision
150    IF ( cloud_droplets )  THEN
151
152!
153!--    Reset summation arrays
154       ql_c = 0.0;  ql_v = 0.0;  ql_vp = 0.0
155
156!
157!--    Droplet growth by condensation / evaporation
158       CALL lpm_droplet_condensation
159
160!
161!--    Particle growth by collision
162       IF ( collision_kernel /= 'none' )  CALL lpm_droplet_collision
163
164    ENDIF
165
166
167!
168!-- If particle advection includes SGS velocity components, calculate the
169!-- required SGS quantities (i.e. gradients of the TKE, as well as horizontally
170!-- averaged profiles of the SGS TKE and the resolved-scale velocity variances)
171    IF ( use_sgs_for_particles )  CALL lpm_init_sgs_tke
172
173
174!
175!-- Initialize the variable storing the total time that a particle has advanced
176!-- within the timestep procedure
177    particles(1:number_of_particles)%dt_sum = 0.0
178
179
180!
181!-- Timestep loop for particle advection.
182!-- This loop has to be repeated until the advection time of every particle
183!-- (within the total domain!) has reached the LES timestep (dt_3d).
184!-- In case of including the SGS velocities, the particle timestep may be
185!-- smaller than the LES timestep (because of the Lagrangian timescale restric-
186!-- tion) and particles may require to undergo several particle timesteps,
187!-- before the LES timestep is reached. Because the number of these particle
188!-- timesteps to be carried out is unknown at first, these steps are carried
189!-- out in the following infinite loop with exit condition.
190    DO
191
192       CALL cpu_log( log_point_s(44), 'lpm_advec', 'start' )
193
194!
195!--    Initialize the switch used for the loop exit condition checked at the
196!--    end of this loop.
197!--    If at least one particle has failed to reach the LES timestep, this
198!--    switch will be set false.
199       dt_3d_reached_l = .TRUE.
200
201!
202!--    Particle advection
203       CALL lpm_advec
204
205!
206!--    Particle reflection from walls
207       CALL lpm_boundary_conds( 'walls' )
208
209!
210!--    User-defined actions after the calculation of the new particle position
211       CALL user_lpm_advec
212
213!
214!--    Find out, if all particles on every PE have completed the LES timestep
215!--    and set the switch corespondingly
216#if defined( __parallel )
217       IF ( collective_wait )  CALL MPI_BARRIER( comm2d, ierr )
218       CALL MPI_ALLREDUCE( dt_3d_reached_l, dt_3d_reached, 1, MPI_LOGICAL, &
219                           MPI_LAND, comm2d, ierr )
220#else
221       dt_3d_reached = dt_3d_reached_l
222#endif
223
224       CALL cpu_log( log_point_s(44), 'lpm_advec', 'stop' )
225
226!
227!--    Increment time since last release
228       IF ( dt_3d_reached )  time_prel = time_prel + dt_3d
229
230!
231!--    If necessary, release new set of particles
232       IF ( time_prel >= dt_prel  .AND.  end_time_prel > simulated_time  .AND. &
233            dt_3d_reached )  THEN
234
235          CALL lpm_release_set
236
237!
238!--       The MOD function allows for changes in the output interval with
239!--       restart runs.
240          time_prel = MOD( time_prel, MAX( dt_prel, dt_3d ) )
241
242       ENDIF
243
244!
245!--    Horizontal boundary conditions including exchange between subdmains
246       CALL lpm_exchange_horiz
247
248!
249!--    Apply boundary conditions to those particles that have crossed the top or
250!--    bottom boundary and delete those particles, which are older than allowed
251       CALL lpm_boundary_conds( 'bottom/top' )
252
253!
254!--    Pack particles (eliminate those marked for deletion),
255!--    determine new number of particles
256       IF ( number_of_particles > 0  .AND.  deleted_particles > 0 )  THEN
257          CALL lpm_pack_arrays
258       ENDIF
259
260!
261!--    Initialize variables for the next (sub-) timestep, i.e. for marking those
262!--    particles to be deleted after the timestep
263       particle_mask     = .TRUE.
264       deleted_particles = 0
265
266       IF ( use_particle_tails )  THEN
267          tail_mask     = .TRUE.
268       ENDIF
269       deleted_tails = 0
270
271
272       IF ( dt_3d_reached )  EXIT
273
274    ENDDO   ! timestep loop
275
276
277!
278!-- Sort particles in the sequence the gridboxes are stored in the memory
279    time_sort_particles = time_sort_particles + dt_3d
280    IF ( time_sort_particles >= dt_sort_particles )  THEN
281       CALL lpm_sort_arrays
282       time_sort_particles = MOD( time_sort_particles, &
283                                  MAX( dt_sort_particles, dt_3d ) )
284    ENDIF
285
286
287!
288!-- Calculate the new liquid water content for each grid box
289    IF ( cloud_droplets )  CALL lpm_calc_liquid_water_content
290
291
292!
293!-- Set particle attributes.
294!-- Feature is not available if collision is activated, because the respective
295!-- particle attribute (class) is then used for storing the particle radius
296!-- class.
297    IF ( collision_kernel == 'none' )  CALL lpm_set_attributes
298
299
300!
301!-- Set particle attributes defined by the user
302    CALL user_lpm_set_attributes
303
304
305!
306!-- If required, add the current particle positions to the particle tails
307    IF ( use_particle_tails )  CALL lpm_extend_tails
308
309
310!
311!-- Write particle statistics (in particular the number of particles
312!-- exchanged between the subdomains) on file
313    IF ( write_particle_statistics )  CALL lpm_write_exchange_statistics
314
315    CALL cpu_log( log_point(25), 'lpm', 'stop' )
316
317
318 END SUBROUTINE lpm
Note: See TracBrowser for help on using the repository browser.