| 1 | !> @file lpm_advec.f90 |
|---|
| 2 | !------------------------------------------------------------------------------! |
|---|
| 3 | ! This file is part of the PALM model system. |
|---|
| 4 | ! |
|---|
| 5 | ! PALM is free software: you can redistribute it and/or modify it under the |
|---|
| 6 | ! terms of the GNU General Public License as published by the Free Software |
|---|
| 7 | ! Foundation, either version 3 of the License, or (at your option) any later |
|---|
| 8 | ! 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 1997-2018 Leibniz Universitaet Hannover |
|---|
| 18 | !------------------------------------------------------------------------------! |
|---|
| 19 | ! |
|---|
| 20 | ! Current revisions: |
|---|
| 21 | ! ------------------ |
|---|
| 22 | ! |
|---|
| 23 | ! |
|---|
| 24 | ! Former revisions: |
|---|
| 25 | ! ----------------- |
|---|
| 26 | ! $Id: lpm_advec.f90 2718 2018-01-02 08:49:38Z kanani $ |
|---|
| 27 | ! Corrected "Former revisions" section |
|---|
| 28 | ! |
|---|
| 29 | ! 2701 2017-12-15 15:40:50Z suehring |
|---|
| 30 | ! Changes from last commit documented |
|---|
| 31 | ! |
|---|
| 32 | ! 2698 2017-12-14 18:46:24Z suehring |
|---|
| 33 | ! Particle interpolations at walls in case of SGS velocities revised and not |
|---|
| 34 | ! required parts are removed. (responsible Philipp Thiele) |
|---|
| 35 | ! Bugfix in get_topography_top_index |
|---|
| 36 | ! |
|---|
| 37 | ! 2696 2017-12-14 17:12:51Z kanani |
|---|
| 38 | ! Change in file header (GPL part) |
|---|
| 39 | ! |
|---|
| 40 | ! 2630 2017-11-20 12:58:20Z schwenkel |
|---|
| 41 | ! Removed indices ilog and jlog which are no longer needed since particle box |
|---|
| 42 | ! locations are identical to scalar boxes and topography. |
|---|
| 43 | ! |
|---|
| 44 | ! 2628 2017-11-20 12:40:38Z raasch |
|---|
| 45 | ! bugfix in logarithmic interpolation of v-component (usws was used by mistake) |
|---|
| 46 | ! |
|---|
| 47 | ! 2606 2017-11-10 10:36:31Z schwenkel |
|---|
| 48 | ! Changed particle box locations: center of particle box now coincides |
|---|
| 49 | ! with scalar grid point of same index. |
|---|
| 50 | ! Renamed module and subroutines: lpm_pack_arrays_mod -> lpm_pack_and_sort_mod |
|---|
| 51 | ! lpm_pack_all_arrays -> lpm_sort_in_subboxes, lpm_pack_arrays -> lpm_pack |
|---|
| 52 | ! lpm_sort -> lpm_sort_timeloop_done |
|---|
| 53 | ! |
|---|
| 54 | ! 2417 2017-09-06 15:22:27Z suehring |
|---|
| 55 | ! Particle loops adapted for sub-box structure, i.e. for each sub-box the |
|---|
| 56 | ! particle loop runs from start_index up to end_index instead from 1 to |
|---|
| 57 | ! number_of_particles. This way, it is possible to skip unnecessary |
|---|
| 58 | ! computations for particles that already completed the LES timestep. |
|---|
| 59 | ! |
|---|
| 60 | ! 2318 2017-07-20 17:27:44Z suehring |
|---|
| 61 | ! Get topography top index via Function call |
|---|
| 62 | ! |
|---|
| 63 | ! 2317 2017-07-20 17:27:19Z suehring |
|---|
| 64 | ! |
|---|
| 65 | ! 2232 2017-05-30 17:47:52Z suehring |
|---|
| 66 | ! Adjustments to new topography and surface concept |
|---|
| 67 | ! |
|---|
| 68 | ! 2100 2017-01-05 16:40:16Z suehring |
|---|
| 69 | ! Prevent extremely large SGS-velocities in regions where TKE is zero, e.g. |
|---|
| 70 | ! at the begin of simulations and/or in non-turbulent regions. |
|---|
| 71 | ! |
|---|
| 72 | ! 2000 2016-08-20 18:09:15Z knoop |
|---|
| 73 | ! Forced header and separation lines into 80 columns |
|---|
| 74 | ! |
|---|
| 75 | ! 1936 2016-06-13 13:37:44Z suehring |
|---|
| 76 | ! Formatting adjustments |
|---|
| 77 | ! |
|---|
| 78 | ! 1929 2016-06-09 16:25:25Z suehring |
|---|
| 79 | ! Put stochastic equation in an extra subroutine. |
|---|
| 80 | ! Set flag for stochastic equation to communicate whether a particle is near |
|---|
| 81 | ! topography. This case, memory and drift term are disabled in the Weil equation. |
|---|
| 82 | ! |
|---|
| 83 | ! Enable vertical logarithmic interpolation also above topography. This case, |
|---|
| 84 | ! set a lower limit for the friction velocity, as it can become very small |
|---|
| 85 | ! in narrow street canyons, leading to too large particle speeds. |
|---|
| 86 | ! |
|---|
| 87 | ! 1888 2016-04-21 12:20:49Z suehring |
|---|
| 88 | ! Bugfix concerning logarithmic interpolation of particle speed |
|---|
| 89 | ! |
|---|
| 90 | ! 1822 2016-04-07 07:49:42Z hoffmann |
|---|
| 91 | ! Random velocity fluctuations for particles added. Terminal fall velocity |
|---|
| 92 | ! for droplets is calculated from a parameterization (which is better than |
|---|
| 93 | ! the previous, physically correct calculation, which demands a very short |
|---|
| 94 | ! time step that is not used in the model). |
|---|
| 95 | ! |
|---|
| 96 | ! Unused variables deleted. |
|---|
| 97 | ! |
|---|
| 98 | ! 1691 2015-10-26 16:17:44Z maronga |
|---|
| 99 | ! Renamed prandtl_layer to constant_flux_layer. |
|---|
| 100 | ! |
|---|
| 101 | ! 1685 2015-10-08 07:32:13Z raasch |
|---|
| 102 | ! TKE check for negative values (so far, only zero value was checked) |
|---|
| 103 | ! offset_ocean_nzt_m1 removed |
|---|
| 104 | ! |
|---|
| 105 | ! 1682 2015-10-07 23:56:08Z knoop |
|---|
| 106 | ! Code annotations made doxygen readable |
|---|
| 107 | ! |
|---|
| 108 | ! 1583 2015-04-15 12:16:27Z suehring |
|---|
| 109 | ! Bugfix: particle advection within Prandtl-layer in case of Galilei |
|---|
| 110 | ! transformation. |
|---|
| 111 | ! |
|---|
| 112 | ! 1369 2014-04-24 05:57:38Z raasch |
|---|
| 113 | ! usage of module interfaces removed |
|---|
| 114 | ! |
|---|
| 115 | ! 1359 2014-04-11 17:15:14Z hoffmann |
|---|
| 116 | ! New particle structure integrated. |
|---|
| 117 | ! Kind definition added to all floating point numbers. |
|---|
| 118 | ! |
|---|
| 119 | ! 1322 2014-03-20 16:38:49Z raasch |
|---|
| 120 | ! REAL constants defined as wp_kind |
|---|
| 121 | ! |
|---|
| 122 | ! 1320 2014-03-20 08:40:49Z raasch |
|---|
| 123 | ! ONLY-attribute added to USE-statements, |
|---|
| 124 | ! kind-parameters added to all INTEGER and REAL declaration statements, |
|---|
| 125 | ! kinds are defined in new module kinds, |
|---|
| 126 | ! revision history before 2012 removed, |
|---|
| 127 | ! comment fields (!:) to be used for variable explanations added to |
|---|
| 128 | ! all variable declaration statements |
|---|
| 129 | ! |
|---|
| 130 | ! 1314 2014-03-14 18:25:17Z suehring |
|---|
| 131 | ! Vertical logarithmic interpolation of horizontal particle speed for particles |
|---|
| 132 | ! between roughness height and first vertical grid level. |
|---|
| 133 | ! |
|---|
| 134 | ! 1036 2012-10-22 13:43:42Z raasch |
|---|
| 135 | ! code put under GPL (PALM 3.9) |
|---|
| 136 | ! |
|---|
| 137 | ! 849 2012-03-15 10:35:09Z raasch |
|---|
| 138 | ! initial revision (former part of advec_particles) |
|---|
| 139 | ! |
|---|
| 140 | ! |
|---|
| 141 | ! Description: |
|---|
| 142 | ! ------------ |
|---|
| 143 | !> Calculation of new particle positions due to advection using a simple Euler |
|---|
| 144 | !> scheme. Particles may feel inertia effects. SGS transport can be included |
|---|
| 145 | !> using the stochastic model of Weil et al. (2004, JAS, 61, 2877-2887). |
|---|
| 146 | !------------------------------------------------------------------------------! |
|---|
| 147 | SUBROUTINE lpm_advec (ip,jp,kp) |
|---|
| 148 | |
|---|
| 149 | |
|---|
| 150 | USE arrays_3d, & |
|---|
| 151 | ONLY: de_dx, de_dy, de_dz, diss, e, km, u, v, w, zu, zw |
|---|
| 152 | |
|---|
| 153 | USE cpulog |
|---|
| 154 | |
|---|
| 155 | USE pegrid |
|---|
| 156 | |
|---|
| 157 | USE control_parameters, & |
|---|
| 158 | ONLY: atmos_ocean_sign, cloud_droplets, constant_flux_layer, dt_3d, & |
|---|
| 159 | dt_3d_reached_l, dz, g, kappa, topography, u_gtrans, v_gtrans |
|---|
| 160 | |
|---|
| 161 | USE grid_variables, & |
|---|
| 162 | ONLY: ddx, dx, ddy, dy |
|---|
| 163 | |
|---|
| 164 | USE indices, & |
|---|
| 165 | ONLY: nzb, nzt, wall_flags_0 |
|---|
| 166 | |
|---|
| 167 | USE kinds |
|---|
| 168 | |
|---|
| 169 | USE particle_attributes, & |
|---|
| 170 | ONLY: block_offset, c_0, dt_min_part, grid_particles, & |
|---|
| 171 | iran_part, log_z_z0, number_of_particles, number_of_sublayers, & |
|---|
| 172 | particles, particle_groups, offset_ocean_nzt, sgs_wf_part, & |
|---|
| 173 | use_sgs_for_particles, vertical_particle_advection, z0_av_global |
|---|
| 174 | |
|---|
| 175 | USE statistics, & |
|---|
| 176 | ONLY: hom |
|---|
| 177 | |
|---|
| 178 | USE surface_mod, & |
|---|
| 179 | ONLY: get_topography_top_index_ji, surf_def_h, surf_lsm_h, surf_usm_h |
|---|
| 180 | |
|---|
| 181 | IMPLICIT NONE |
|---|
| 182 | |
|---|
| 183 | LOGICAL :: subbox_at_wall !< flag to see if the current subgridbox is adjacent to a wall |
|---|
| 184 | |
|---|
| 185 | INTEGER(iwp) :: agp !< loop variable |
|---|
| 186 | INTEGER(iwp) :: gp_outside_of_building(1:8) !< number of grid points used for particle interpolation in case of topography |
|---|
| 187 | INTEGER(iwp) :: i !< index variable along x |
|---|
| 188 | INTEGER(iwp) :: ip !< index variable along x |
|---|
| 189 | INTEGER(iwp) :: j !< index variable along y |
|---|
| 190 | INTEGER(iwp) :: jp !< index variable along y |
|---|
| 191 | INTEGER(iwp) :: k !< index variable along z |
|---|
| 192 | INTEGER(iwp) :: k_wall !< vertical index of topography top |
|---|
| 193 | INTEGER(iwp) :: kp !< index variable along z |
|---|
| 194 | INTEGER(iwp) :: kw !< index variable along z |
|---|
| 195 | INTEGER(iwp) :: n !< loop variable over all particles in a grid box |
|---|
| 196 | INTEGER(iwp) :: nb !< block number particles are sorted in |
|---|
| 197 | INTEGER(iwp) :: num_gp !< number of adjacent grid points inside topography |
|---|
| 198 | INTEGER(iwp) :: surf_start !< Index on surface data-type for current grid box |
|---|
| 199 | |
|---|
| 200 | INTEGER(iwp), DIMENSION(0:7) :: start_index !< start particle index for current block |
|---|
| 201 | INTEGER(iwp), DIMENSION(0:7) :: end_index !< start particle index for current block |
|---|
| 202 | |
|---|
| 203 | REAL(wp) :: aa !< dummy argument for horizontal particle interpolation |
|---|
| 204 | REAL(wp) :: bb !< dummy argument for horizontal particle interpolation |
|---|
| 205 | REAL(wp) :: cc !< dummy argument for horizontal particle interpolation |
|---|
| 206 | REAL(wp) :: d_sum !< dummy argument for horizontal particle interpolation in case of topography |
|---|
| 207 | REAL(wp) :: d_z_p_z0 !< inverse of interpolation length for logarithmic interpolation |
|---|
| 208 | REAL(wp) :: dd !< dummy argument for horizontal particle interpolation |
|---|
| 209 | REAL(wp) :: de_dx_int_l !< x/y-interpolated TKE gradient (x) at particle position at lower vertical level |
|---|
| 210 | REAL(wp) :: de_dx_int_u !< x/y-interpolated TKE gradient (x) at particle position at upper vertical level |
|---|
| 211 | REAL(wp) :: de_dy_int_l !< x/y-interpolated TKE gradient (y) at particle position at lower vertical level |
|---|
| 212 | REAL(wp) :: de_dy_int_u !< x/y-interpolated TKE gradient (y) at particle position at upper vertical level |
|---|
| 213 | REAL(wp) :: de_dt !< temporal derivative of TKE experienced by the particle |
|---|
| 214 | REAL(wp) :: de_dt_min !< lower level for temporal TKE derivative |
|---|
| 215 | REAL(wp) :: de_dz_int_l !< x/y-interpolated TKE gradient (z) at particle position at lower vertical level |
|---|
| 216 | REAL(wp) :: de_dz_int_u !< x/y-interpolated TKE gradient (z) at particle position at upper vertical level |
|---|
| 217 | REAL(wp) :: diameter !< diamter of droplet |
|---|
| 218 | REAL(wp) :: diss_int_l !< x/y-interpolated dissipation at particle position at lower vertical level |
|---|
| 219 | REAL(wp) :: diss_int_u !< x/y-interpolated dissipation at particle position at upper vertical level |
|---|
| 220 | REAL(wp) :: dt_gap !< remaining time until particle time integration reaches LES time |
|---|
| 221 | REAL(wp) :: dt_particle_m !< previous particle time step |
|---|
| 222 | REAL(wp) :: e_int_l !< x/y-interpolated TKE at particle position at lower vertical level |
|---|
| 223 | REAL(wp) :: e_int_u !< x/y-interpolated TKE at particle position at upper vertical level |
|---|
| 224 | REAL(wp) :: e_mean_int !< horizontal mean TKE at particle height |
|---|
| 225 | REAL(wp) :: exp_arg !< |
|---|
| 226 | REAL(wp) :: exp_term !< |
|---|
| 227 | REAL(wp) :: gg !< dummy argument for horizontal particle interpolation |
|---|
| 228 | REAL(wp) :: height_p !< dummy argument for logarithmic interpolation |
|---|
| 229 | REAL(wp) :: lagr_timescale !< Lagrangian timescale |
|---|
| 230 | REAL(wp) :: location(1:30,1:3) !< wall locations |
|---|
| 231 | REAL(wp) :: log_z_z0_int !< logarithmus used for surface_layer interpolation |
|---|
| 232 | REAL(wp) :: random_gauss !< |
|---|
| 233 | REAL(wp) :: RL !< Lagrangian autocorrelation coefficient |
|---|
| 234 | REAL(wp) :: rg1 !< Gaussian distributed random number |
|---|
| 235 | REAL(wp) :: rg2 !< Gaussian distributed random number |
|---|
| 236 | REAL(wp) :: rg3 !< Gaussian distributed random number |
|---|
| 237 | REAL(wp) :: sigma !< velocity standard deviation |
|---|
| 238 | REAL(wp) :: u_int_l !< x/y-interpolated u-component at particle position at lower vertical level |
|---|
| 239 | REAL(wp) :: u_int_u !< x/y-interpolated u-component at particle position at upper vertical level |
|---|
| 240 | REAL(wp) :: us_int !< friction velocity at particle grid box |
|---|
| 241 | REAL(wp) :: usws_int !< surface momentum flux (u component) at particle grid box |
|---|
| 242 | REAL(wp) :: v_int_l !< x/y-interpolated v-component at particle position at lower vertical level |
|---|
| 243 | REAL(wp) :: v_int_u !< x/y-interpolated v-component at particle position at upper vertical level |
|---|
| 244 | REAL(wp) :: vsws_int !< surface momentum flux (u component) at particle grid box |
|---|
| 245 | REAL(wp) :: vv_int !< |
|---|
| 246 | REAL(wp) :: w_int_l !< x/y-interpolated w-component at particle position at lower vertical level |
|---|
| 247 | REAL(wp) :: w_int_u !< x/y-interpolated w-component at particle position at upper vertical level |
|---|
| 248 | REAL(wp) :: w_s !< terminal velocity of droplets |
|---|
| 249 | REAL(wp) :: x !< dummy argument for horizontal particle interpolation |
|---|
| 250 | REAL(wp) :: y !< dummy argument for horizontal particle interpolation |
|---|
| 251 | REAL(wp) :: z_p !< surface layer height (0.5 dz) |
|---|
| 252 | |
|---|
| 253 | REAL(wp), PARAMETER :: a_rog = 9.65_wp !< parameter for fall velocity |
|---|
| 254 | REAL(wp), PARAMETER :: b_rog = 10.43_wp !< parameter for fall velocity |
|---|
| 255 | REAL(wp), PARAMETER :: c_rog = 0.6_wp !< parameter for fall velocity |
|---|
| 256 | REAL(wp), PARAMETER :: k_cap_rog = 4.0_wp !< parameter for fall velocity |
|---|
| 257 | REAL(wp), PARAMETER :: k_low_rog = 12.0_wp !< parameter for fall velocity |
|---|
| 258 | REAL(wp), PARAMETER :: d0_rog = 0.745_wp !< separation diameter |
|---|
| 259 | |
|---|
| 260 | REAL(wp), DIMENSION(1:30) :: d_gp_pl !< dummy argument for particle interpolation scheme in case of topography |
|---|
| 261 | REAL(wp), DIMENSION(1:30) :: de_dxi !< horizontal TKE gradient along x at adjacent wall |
|---|
| 262 | REAL(wp), DIMENSION(1:30) :: de_dyi !< horizontal TKE gradient along y at adjacent wall |
|---|
| 263 | REAL(wp), DIMENSION(1:30) :: de_dzi !< horizontal TKE gradient along z at adjacent wall |
|---|
| 264 | REAL(wp), DIMENSION(1:30) :: dissi !< dissipation at adjacent wall |
|---|
| 265 | REAL(wp), DIMENSION(1:30) :: ei !< TKE at adjacent wall |
|---|
| 266 | |
|---|
| 267 | REAL(wp), DIMENSION(number_of_particles) :: term_1_2 !< flag to communicate whether a particle is near topography or not |
|---|
| 268 | REAL(wp), DIMENSION(number_of_particles) :: dens_ratio !< |
|---|
| 269 | REAL(wp), DIMENSION(number_of_particles) :: de_dx_int !< horizontal TKE gradient along x at particle position |
|---|
| 270 | REAL(wp), DIMENSION(number_of_particles) :: de_dy_int !< horizontal TKE gradient along y at particle position |
|---|
| 271 | REAL(wp), DIMENSION(number_of_particles) :: de_dz_int !< horizontal TKE gradient along z at particle position |
|---|
| 272 | REAL(wp), DIMENSION(number_of_particles) :: diss_int !< dissipation at particle position |
|---|
| 273 | REAL(wp), DIMENSION(number_of_particles) :: dt_particle !< particle time step |
|---|
| 274 | REAL(wp), DIMENSION(number_of_particles) :: e_int !< TKE at particle position |
|---|
| 275 | REAL(wp), DIMENSION(number_of_particles) :: fs_int !< weighting factor for subgrid-scale particle speed |
|---|
| 276 | REAL(wp), DIMENSION(number_of_particles) :: u_int !< u-component of particle speed |
|---|
| 277 | REAL(wp), DIMENSION(number_of_particles) :: v_int !< v-component of particle speed |
|---|
| 278 | REAL(wp), DIMENSION(number_of_particles) :: w_int !< w-component of particle speed |
|---|
| 279 | REAL(wp), DIMENSION(number_of_particles) :: xv !< x-position |
|---|
| 280 | REAL(wp), DIMENSION(number_of_particles) :: yv !< y-position |
|---|
| 281 | REAL(wp), DIMENSION(number_of_particles) :: zv !< z-position |
|---|
| 282 | |
|---|
| 283 | REAL(wp), DIMENSION(number_of_particles, 3) :: rg !< vector of Gaussian distributed random numbers |
|---|
| 284 | |
|---|
| 285 | CALL cpu_log( log_point_s(44), 'lpm_advec', 'continue' ) |
|---|
| 286 | |
|---|
| 287 | ! |
|---|
| 288 | !-- Determine height of Prandtl layer and distance between Prandtl-layer |
|---|
| 289 | !-- height and horizontal mean roughness height, which are required for |
|---|
| 290 | !-- vertical logarithmic interpolation of horizontal particle speeds |
|---|
| 291 | !-- (for particles below first vertical grid level). |
|---|
| 292 | z_p = zu(nzb+1) - zw(nzb) |
|---|
| 293 | d_z_p_z0 = 1.0_wp / ( z_p - z0_av_global ) |
|---|
| 294 | |
|---|
| 295 | start_index = grid_particles(kp,jp,ip)%start_index |
|---|
| 296 | end_index = grid_particles(kp,jp,ip)%end_index |
|---|
| 297 | |
|---|
| 298 | xv = particles(1:number_of_particles)%x |
|---|
| 299 | yv = particles(1:number_of_particles)%y |
|---|
| 300 | zv = particles(1:number_of_particles)%z |
|---|
| 301 | |
|---|
| 302 | DO nb = 0, 7 |
|---|
| 303 | ! |
|---|
| 304 | !-- Interpolate u velocity-component |
|---|
| 305 | i = ip |
|---|
| 306 | j = jp + block_offset(nb)%j_off |
|---|
| 307 | k = kp + block_offset(nb)%k_off |
|---|
| 308 | |
|---|
| 309 | DO n = start_index(nb), end_index(nb) |
|---|
| 310 | ! |
|---|
| 311 | !-- Interpolation of the u velocity component onto particle position. |
|---|
| 312 | !-- Particles are interpolation bi-linearly in the horizontal and a |
|---|
| 313 | !-- linearly in the vertical. An exception is made for particles below |
|---|
| 314 | !-- the first vertical grid level in case of a prandtl layer. In this |
|---|
| 315 | !-- case the horizontal particle velocity components are determined using |
|---|
| 316 | !-- Monin-Obukhov relations (if branch). |
|---|
| 317 | !-- First, check if particle is located below first vertical grid level |
|---|
| 318 | !-- above topography (Prandtl-layer height) |
|---|
| 319 | !-- Determine vertical index of topography top |
|---|
| 320 | k_wall = get_topography_top_index_ji( jp, ip, 's' ) |
|---|
| 321 | |
|---|
| 322 | IF ( constant_flux_layer .AND. zv(n) - zw(k_wall) < z_p ) THEN |
|---|
| 323 | ! |
|---|
| 324 | !-- Resolved-scale horizontal particle velocity is zero below z0. |
|---|
| 325 | IF ( zv(n) - zw(k_wall) < z0_av_global ) THEN |
|---|
| 326 | u_int(n) = 0.0_wp |
|---|
| 327 | ELSE |
|---|
| 328 | ! |
|---|
| 329 | !-- Determine the sublayer. Further used as index. |
|---|
| 330 | height_p = ( zv(n) - zw(k_wall) - z0_av_global ) & |
|---|
| 331 | * REAL( number_of_sublayers, KIND=wp ) & |
|---|
| 332 | * d_z_p_z0 |
|---|
| 333 | ! |
|---|
| 334 | !-- Calculate LOG(z/z0) for exact particle height. Therefore, |
|---|
| 335 | !-- interpolate linearly between precalculated logarithm. |
|---|
| 336 | log_z_z0_int = log_z_z0(INT(height_p)) & |
|---|
| 337 | + ( height_p - INT(height_p) ) & |
|---|
| 338 | * ( log_z_z0(INT(height_p)+1) & |
|---|
| 339 | - log_z_z0(INT(height_p)) & |
|---|
| 340 | ) |
|---|
| 341 | ! |
|---|
| 342 | !-- Get friction velocity and momentum flux from new surface data |
|---|
| 343 | !-- types. |
|---|
| 344 | IF ( surf_def_h(0)%start_index(jp,ip) <= & |
|---|
| 345 | surf_def_h(0)%end_index(jp,ip) ) THEN |
|---|
| 346 | surf_start = surf_def_h(0)%start_index(jp,ip) |
|---|
| 347 | !-- Limit friction velocity. In narrow canyons or holes the |
|---|
| 348 | !-- friction velocity can become very small, resulting in a too |
|---|
| 349 | !-- large particle speed. |
|---|
| 350 | us_int = MAX( surf_def_h(0)%us(surf_start), 0.01_wp ) |
|---|
| 351 | usws_int = surf_def_h(0)%usws(surf_start) |
|---|
| 352 | ELSEIF ( surf_lsm_h%start_index(jp,ip) <= & |
|---|
| 353 | surf_lsm_h%end_index(jp,ip) ) THEN |
|---|
| 354 | surf_start = surf_lsm_h%start_index(jp,ip) |
|---|
| 355 | us_int = MAX( surf_lsm_h%us(surf_start), 0.01_wp ) |
|---|
| 356 | usws_int = surf_lsm_h%usws(surf_start) |
|---|
| 357 | ELSEIF ( surf_usm_h%start_index(jp,ip) <= & |
|---|
| 358 | surf_usm_h%end_index(jp,ip) ) THEN |
|---|
| 359 | surf_start = surf_usm_h%start_index(jp,ip) |
|---|
| 360 | us_int = MAX( surf_usm_h%us(surf_start), 0.01_wp ) |
|---|
| 361 | usws_int = surf_usm_h%usws(surf_start) |
|---|
| 362 | ENDIF |
|---|
| 363 | |
|---|
| 364 | ! |
|---|
| 365 | !-- Neutral solution is applied for all situations, e.g. also for |
|---|
| 366 | !-- unstable and stable situations. Even though this is not exact |
|---|
| 367 | !-- this saves a lot of CPU time since several calls of intrinsic |
|---|
| 368 | !-- FORTRAN procedures (LOG, ATAN) are avoided, This is justified |
|---|
| 369 | !-- as sensitivity studies revealed no significant effect of |
|---|
| 370 | !-- using the neutral solution also for un/stable situations. |
|---|
| 371 | u_int(n) = -usws_int / ( us_int * kappa + 1E-10_wp ) & |
|---|
| 372 | * log_z_z0_int - u_gtrans |
|---|
| 373 | |
|---|
| 374 | ENDIF |
|---|
| 375 | ! |
|---|
| 376 | !-- Particle above the first grid level. Bi-linear interpolation in the |
|---|
| 377 | !-- horizontal and linear interpolation in the vertical direction. |
|---|
| 378 | ELSE |
|---|
| 379 | |
|---|
| 380 | x = xv(n) + ( 0.5_wp - i ) * dx |
|---|
| 381 | y = yv(n) - j * dy |
|---|
| 382 | aa = x**2 + y**2 |
|---|
| 383 | bb = ( dx - x )**2 + y**2 |
|---|
| 384 | cc = x**2 + ( dy - y )**2 |
|---|
| 385 | dd = ( dx - x )**2 + ( dy - y )**2 |
|---|
| 386 | gg = aa + bb + cc + dd |
|---|
| 387 | |
|---|
| 388 | u_int_l = ( ( gg - aa ) * u(k,j,i) + ( gg - bb ) * u(k,j,i+1) & |
|---|
| 389 | + ( gg - cc ) * u(k,j+1,i) + ( gg - dd ) * & |
|---|
| 390 | u(k,j+1,i+1) ) / ( 3.0_wp * gg ) - u_gtrans |
|---|
| 391 | |
|---|
| 392 | IF ( k == nzt ) THEN |
|---|
| 393 | u_int(n) = u_int_l |
|---|
| 394 | ELSE |
|---|
| 395 | u_int_u = ( ( gg-aa ) * u(k+1,j,i) + ( gg-bb ) * u(k+1,j,i+1) & |
|---|
| 396 | + ( gg-cc ) * u(k+1,j+1,i) + ( gg-dd ) * & |
|---|
| 397 | u(k+1,j+1,i+1) ) / ( 3.0_wp * gg ) - u_gtrans |
|---|
| 398 | u_int(n) = u_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 399 | ( u_int_u - u_int_l ) |
|---|
| 400 | ENDIF |
|---|
| 401 | |
|---|
| 402 | ENDIF |
|---|
| 403 | |
|---|
| 404 | ENDDO |
|---|
| 405 | ! |
|---|
| 406 | !-- Same procedure for interpolation of the v velocity-component |
|---|
| 407 | i = ip + block_offset(nb)%i_off |
|---|
| 408 | j = jp |
|---|
| 409 | k = kp + block_offset(nb)%k_off |
|---|
| 410 | |
|---|
| 411 | DO n = start_index(nb), end_index(nb) |
|---|
| 412 | |
|---|
| 413 | ! |
|---|
| 414 | !-- Determine vertical index of topography top |
|---|
| 415 | k_wall = get_topography_top_index_ji( jp,ip, 's' ) |
|---|
| 416 | |
|---|
| 417 | IF ( constant_flux_layer .AND. zv(n) - zw(k_wall) < z_p ) THEN |
|---|
| 418 | IF ( zv(n) - zw(k_wall) < z0_av_global ) THEN |
|---|
| 419 | ! |
|---|
| 420 | !-- Resolved-scale horizontal particle velocity is zero below z0. |
|---|
| 421 | v_int(n) = 0.0_wp |
|---|
| 422 | ELSE |
|---|
| 423 | ! |
|---|
| 424 | !-- Determine the sublayer. Further used as index. Please note, |
|---|
| 425 | !-- logarithmus can not be reused from above, as in in case of |
|---|
| 426 | !-- topography particle on u-grid can be above surface-layer height, |
|---|
| 427 | !-- whereas it can be below on v-grid. |
|---|
| 428 | height_p = ( zv(n) - zw(k_wall) - z0_av_global ) & |
|---|
| 429 | * REAL( number_of_sublayers, KIND=wp ) & |
|---|
| 430 | * d_z_p_z0 |
|---|
| 431 | ! |
|---|
| 432 | !-- Calculate LOG(z/z0) for exact particle height. Therefore, |
|---|
| 433 | !-- interpolate linearly between precalculated logarithm. |
|---|
| 434 | log_z_z0_int = log_z_z0(INT(height_p)) & |
|---|
| 435 | + ( height_p - INT(height_p) ) & |
|---|
| 436 | * ( log_z_z0(INT(height_p)+1) & |
|---|
| 437 | - log_z_z0(INT(height_p)) & |
|---|
| 438 | ) |
|---|
| 439 | ! |
|---|
| 440 | !-- Get friction velocity and momentum flux from new surface data |
|---|
| 441 | !-- types. |
|---|
| 442 | IF ( surf_def_h(0)%start_index(jp,ip) <= & |
|---|
| 443 | surf_def_h(0)%end_index(jp,ip) ) THEN |
|---|
| 444 | surf_start = surf_def_h(0)%start_index(jp,ip) |
|---|
| 445 | !-- Limit friction velocity. In narrow canyons or holes the |
|---|
| 446 | !-- friction velocity can become very small, resulting in a too |
|---|
| 447 | !-- large particle speed. |
|---|
| 448 | us_int = MAX( surf_def_h(0)%us(surf_start), 0.01_wp ) |
|---|
| 449 | vsws_int = surf_def_h(0)%vsws(surf_start) |
|---|
| 450 | ELSEIF ( surf_lsm_h%start_index(jp,ip) <= & |
|---|
| 451 | surf_lsm_h%end_index(jp,ip) ) THEN |
|---|
| 452 | surf_start = surf_lsm_h%start_index(jp,ip) |
|---|
| 453 | us_int = MAX( surf_lsm_h%us(surf_start), 0.01_wp ) |
|---|
| 454 | vsws_int = surf_lsm_h%vsws(surf_start) |
|---|
| 455 | ELSEIF ( surf_usm_h%start_index(jp,ip) <= & |
|---|
| 456 | surf_usm_h%end_index(jp,ip) ) THEN |
|---|
| 457 | surf_start = surf_usm_h%start_index(jp,ip) |
|---|
| 458 | us_int = MAX( surf_usm_h%us(surf_start), 0.01_wp ) |
|---|
| 459 | vsws_int = surf_usm_h%vsws(surf_start) |
|---|
| 460 | ENDIF |
|---|
| 461 | ! |
|---|
| 462 | !-- Neutral solution is applied for all situations, e.g. also for |
|---|
| 463 | !-- unstable and stable situations. Even though this is not exact |
|---|
| 464 | !-- this saves a lot of CPU time since several calls of intrinsic |
|---|
| 465 | !-- FORTRAN procedures (LOG, ATAN) are avoided, This is justified |
|---|
| 466 | !-- as sensitivity studies revealed no significant effect of |
|---|
| 467 | !-- using the neutral solution also for un/stable situations. |
|---|
| 468 | v_int(n) = -vsws_int / ( us_int * kappa + 1E-10_wp ) & |
|---|
| 469 | * log_z_z0_int - v_gtrans |
|---|
| 470 | |
|---|
| 471 | ENDIF |
|---|
| 472 | |
|---|
| 473 | ELSE |
|---|
| 474 | x = xv(n) - i * dx |
|---|
| 475 | y = yv(n) + ( 0.5_wp - j ) * dy |
|---|
| 476 | aa = x**2 + y**2 |
|---|
| 477 | bb = ( dx - x )**2 + y**2 |
|---|
| 478 | cc = x**2 + ( dy - y )**2 |
|---|
| 479 | dd = ( dx - x )**2 + ( dy - y )**2 |
|---|
| 480 | gg = aa + bb + cc + dd |
|---|
| 481 | |
|---|
| 482 | v_int_l = ( ( gg - aa ) * v(k,j,i) + ( gg - bb ) * v(k,j,i+1) & |
|---|
| 483 | + ( gg - cc ) * v(k,j+1,i) + ( gg - dd ) * v(k,j+1,i+1) & |
|---|
| 484 | ) / ( 3.0_wp * gg ) - v_gtrans |
|---|
| 485 | |
|---|
| 486 | IF ( k == nzt ) THEN |
|---|
| 487 | v_int(n) = v_int_l |
|---|
| 488 | ELSE |
|---|
| 489 | v_int_u = ( ( gg-aa ) * v(k+1,j,i) + ( gg-bb ) * v(k+1,j,i+1) & |
|---|
| 490 | + ( gg-cc ) * v(k+1,j+1,i) + ( gg-dd ) * v(k+1,j+1,i+1) & |
|---|
| 491 | ) / ( 3.0_wp * gg ) - v_gtrans |
|---|
| 492 | v_int(n) = v_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 493 | ( v_int_u - v_int_l ) |
|---|
| 494 | ENDIF |
|---|
| 495 | |
|---|
| 496 | ENDIF |
|---|
| 497 | |
|---|
| 498 | ENDDO |
|---|
| 499 | ! |
|---|
| 500 | !-- Same procedure for interpolation of the w velocity-component |
|---|
| 501 | i = ip + block_offset(nb)%i_off |
|---|
| 502 | j = jp + block_offset(nb)%j_off |
|---|
| 503 | k = kp - 1 |
|---|
| 504 | |
|---|
| 505 | DO n = start_index(nb), end_index(nb) |
|---|
| 506 | |
|---|
| 507 | IF ( vertical_particle_advection(particles(n)%group) ) THEN |
|---|
| 508 | |
|---|
| 509 | x = xv(n) - i * dx |
|---|
| 510 | y = yv(n) - j * dy |
|---|
| 511 | aa = x**2 + y**2 |
|---|
| 512 | bb = ( dx - x )**2 + y**2 |
|---|
| 513 | cc = x**2 + ( dy - y )**2 |
|---|
| 514 | dd = ( dx - x )**2 + ( dy - y )**2 |
|---|
| 515 | gg = aa + bb + cc + dd |
|---|
| 516 | |
|---|
| 517 | w_int_l = ( ( gg - aa ) * w(k,j,i) + ( gg - bb ) * w(k,j,i+1) & |
|---|
| 518 | + ( gg - cc ) * w(k,j+1,i) + ( gg - dd ) * w(k,j+1,i+1) & |
|---|
| 519 | ) / ( 3.0_wp * gg ) |
|---|
| 520 | |
|---|
| 521 | IF ( k == nzt ) THEN |
|---|
| 522 | w_int(n) = w_int_l |
|---|
| 523 | ELSE |
|---|
| 524 | w_int_u = ( ( gg-aa ) * w(k+1,j,i) + & |
|---|
| 525 | ( gg-bb ) * w(k+1,j,i+1) + & |
|---|
| 526 | ( gg-cc ) * w(k+1,j+1,i) + & |
|---|
| 527 | ( gg-dd ) * w(k+1,j+1,i+1) & |
|---|
| 528 | ) / ( 3.0_wp * gg ) |
|---|
| 529 | w_int(n) = w_int_l + ( zv(n) - zw(k) ) / dz * & |
|---|
| 530 | ( w_int_u - w_int_l ) |
|---|
| 531 | ENDIF |
|---|
| 532 | |
|---|
| 533 | ELSE |
|---|
| 534 | |
|---|
| 535 | w_int(n) = 0.0_wp |
|---|
| 536 | |
|---|
| 537 | ENDIF |
|---|
| 538 | |
|---|
| 539 | ENDDO |
|---|
| 540 | |
|---|
| 541 | ENDDO |
|---|
| 542 | |
|---|
| 543 | !-- Interpolate and calculate quantities needed for calculating the SGS |
|---|
| 544 | !-- velocities |
|---|
| 545 | IF ( use_sgs_for_particles .AND. .NOT. cloud_droplets ) THEN |
|---|
| 546 | |
|---|
| 547 | DO nb = 0,7 |
|---|
| 548 | |
|---|
| 549 | subbox_at_wall = .FALSE. |
|---|
| 550 | ! |
|---|
| 551 | !-- In case of topography check if subbox is adjacent to a wall |
|---|
| 552 | IF ( .NOT. topography == 'flat' ) THEN |
|---|
| 553 | i = ip + MERGE( -1_iwp , 1_iwp, BTEST( nb, 2 ) ) |
|---|
| 554 | j = jp + MERGE( -1_iwp , 1_iwp, BTEST( nb, 1 ) ) |
|---|
| 555 | k = kp + MERGE( -1_iwp , 1_iwp, BTEST( nb, 0 ) ) |
|---|
| 556 | IF ( .NOT. BTEST(wall_flags_0(k, jp, ip), 0) .OR. & |
|---|
| 557 | .NOT. BTEST(wall_flags_0(kp, j, ip), 0) .OR. & |
|---|
| 558 | .NOT. BTEST(wall_flags_0(kp, jp, i ), 0) ) & |
|---|
| 559 | THEN |
|---|
| 560 | subbox_at_wall = .TRUE. |
|---|
| 561 | ENDIF |
|---|
| 562 | ENDIF |
|---|
| 563 | IF ( subbox_at_wall ) THEN |
|---|
| 564 | e_int(start_index(nb):end_index(nb)) = e(kp,jp,ip) |
|---|
| 565 | diss_int(start_index(nb):end_index(nb)) = diss(kp,jp,ip) |
|---|
| 566 | de_dx_int(start_index(nb):end_index(nb)) = de_dx(kp,jp,ip) |
|---|
| 567 | de_dy_int(start_index(nb):end_index(nb)) = de_dy(kp,jp,ip) |
|---|
| 568 | de_dz_int(start_index(nb):end_index(nb)) = de_dz(kp,jp,ip) |
|---|
| 569 | ! |
|---|
| 570 | !-- Set flag for stochastic equation. |
|---|
| 571 | term_1_2(start_index(nb):end_index(nb)) = 0.0_wp |
|---|
| 572 | ELSE |
|---|
| 573 | i = ip + block_offset(nb)%i_off |
|---|
| 574 | j = jp + block_offset(nb)%j_off |
|---|
| 575 | k = kp + block_offset(nb)%k_off |
|---|
| 576 | |
|---|
| 577 | DO n = start_index(nb), end_index(nb) |
|---|
| 578 | ! |
|---|
| 579 | !-- Interpolate TKE |
|---|
| 580 | x = xv(n) - i * dx |
|---|
| 581 | y = yv(n) - j * dy |
|---|
| 582 | aa = x**2 + y**2 |
|---|
| 583 | bb = ( dx - x )**2 + y**2 |
|---|
| 584 | cc = x**2 + ( dy - y )**2 |
|---|
| 585 | dd = ( dx - x )**2 + ( dy - y )**2 |
|---|
| 586 | gg = aa + bb + cc + dd |
|---|
| 587 | |
|---|
| 588 | e_int_l = ( ( gg-aa ) * e(k,j,i) + ( gg-bb ) * e(k,j,i+1) & |
|---|
| 589 | + ( gg-cc ) * e(k,j+1,i) + ( gg-dd ) * e(k,j+1,i+1) & |
|---|
| 590 | ) / ( 3.0_wp * gg ) |
|---|
| 591 | |
|---|
| 592 | IF ( k+1 == nzt+1 ) THEN |
|---|
| 593 | e_int(n) = e_int_l |
|---|
| 594 | ELSE |
|---|
| 595 | e_int_u = ( ( gg - aa ) * e(k+1,j,i) + & |
|---|
| 596 | ( gg - bb ) * e(k+1,j,i+1) + & |
|---|
| 597 | ( gg - cc ) * e(k+1,j+1,i) + & |
|---|
| 598 | ( gg - dd ) * e(k+1,j+1,i+1) & |
|---|
| 599 | ) / ( 3.0_wp * gg ) |
|---|
| 600 | e_int(n) = e_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 601 | ( e_int_u - e_int_l ) |
|---|
| 602 | ENDIF |
|---|
| 603 | ! |
|---|
| 604 | !-- Needed to avoid NaN particle velocities (this might not be |
|---|
| 605 | !-- required any more) |
|---|
| 606 | IF ( e_int(n) <= 0.0_wp ) THEN |
|---|
| 607 | e_int(n) = 1.0E-20_wp |
|---|
| 608 | ENDIF |
|---|
| 609 | ! |
|---|
| 610 | !-- Interpolate the TKE gradient along x (adopt incides i,j,k and |
|---|
| 611 | !-- all position variables from above (TKE)) |
|---|
| 612 | de_dx_int_l = ( ( gg - aa ) * de_dx(k,j,i) + & |
|---|
| 613 | ( gg - bb ) * de_dx(k,j,i+1) + & |
|---|
| 614 | ( gg - cc ) * de_dx(k,j+1,i) + & |
|---|
| 615 | ( gg - dd ) * de_dx(k,j+1,i+1) & |
|---|
| 616 | ) / ( 3.0_wp * gg ) |
|---|
| 617 | |
|---|
| 618 | IF ( ( k+1 == nzt+1 ) .OR. ( k == nzb ) ) THEN |
|---|
| 619 | de_dx_int(n) = de_dx_int_l |
|---|
| 620 | ELSE |
|---|
| 621 | de_dx_int_u = ( ( gg - aa ) * de_dx(k+1,j,i) + & |
|---|
| 622 | ( gg - bb ) * de_dx(k+1,j,i+1) + & |
|---|
| 623 | ( gg - cc ) * de_dx(k+1,j+1,i) + & |
|---|
| 624 | ( gg - dd ) * de_dx(k+1,j+1,i+1) & |
|---|
| 625 | ) / ( 3.0_wp * gg ) |
|---|
| 626 | de_dx_int(n) = de_dx_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 627 | ( de_dx_int_u - de_dx_int_l ) |
|---|
| 628 | ENDIF |
|---|
| 629 | ! |
|---|
| 630 | !-- Interpolate the TKE gradient along y |
|---|
| 631 | de_dy_int_l = ( ( gg - aa ) * de_dy(k,j,i) + & |
|---|
| 632 | ( gg - bb ) * de_dy(k,j,i+1) + & |
|---|
| 633 | ( gg - cc ) * de_dy(k,j+1,i) + & |
|---|
| 634 | ( gg - dd ) * de_dy(k,j+1,i+1) & |
|---|
| 635 | ) / ( 3.0_wp * gg ) |
|---|
| 636 | IF ( ( k+1 == nzt+1 ) .OR. ( k == nzb ) ) THEN |
|---|
| 637 | de_dy_int(n) = de_dy_int_l |
|---|
| 638 | ELSE |
|---|
| 639 | de_dy_int_u = ( ( gg - aa ) * de_dy(k+1,j,i) + & |
|---|
| 640 | ( gg - bb ) * de_dy(k+1,j,i+1) + & |
|---|
| 641 | ( gg - cc ) * de_dy(k+1,j+1,i) + & |
|---|
| 642 | ( gg - dd ) * de_dy(k+1,j+1,i+1) & |
|---|
| 643 | ) / ( 3.0_wp * gg ) |
|---|
| 644 | de_dy_int(n) = de_dy_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 645 | ( de_dy_int_u - de_dy_int_l ) |
|---|
| 646 | ENDIF |
|---|
| 647 | |
|---|
| 648 | ! |
|---|
| 649 | !-- Interpolate the TKE gradient along z |
|---|
| 650 | IF ( zv(n) < 0.5_wp * dz ) THEN |
|---|
| 651 | de_dz_int(n) = 0.0_wp |
|---|
| 652 | ELSE |
|---|
| 653 | de_dz_int_l = ( ( gg - aa ) * de_dz(k,j,i) + & |
|---|
| 654 | ( gg - bb ) * de_dz(k,j,i+1) + & |
|---|
| 655 | ( gg - cc ) * de_dz(k,j+1,i) + & |
|---|
| 656 | ( gg - dd ) * de_dz(k,j+1,i+1) & |
|---|
| 657 | ) / ( 3.0_wp * gg ) |
|---|
| 658 | |
|---|
| 659 | IF ( ( k+1 == nzt+1 ) .OR. ( k == nzb ) ) THEN |
|---|
| 660 | de_dz_int(n) = de_dz_int_l |
|---|
| 661 | ELSE |
|---|
| 662 | de_dz_int_u = ( ( gg - aa ) * de_dz(k+1,j,i) + & |
|---|
| 663 | ( gg - bb ) * de_dz(k+1,j,i+1) + & |
|---|
| 664 | ( gg - cc ) * de_dz(k+1,j+1,i) + & |
|---|
| 665 | ( gg - dd ) * de_dz(k+1,j+1,i+1) & |
|---|
| 666 | ) / ( 3.0_wp * gg ) |
|---|
| 667 | de_dz_int(n) = de_dz_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 668 | ( de_dz_int_u - de_dz_int_l ) |
|---|
| 669 | ENDIF |
|---|
| 670 | ENDIF |
|---|
| 671 | |
|---|
| 672 | ! |
|---|
| 673 | !-- Interpolate the dissipation of TKE |
|---|
| 674 | diss_int_l = ( ( gg - aa ) * diss(k,j,i) + & |
|---|
| 675 | ( gg - bb ) * diss(k,j,i+1) + & |
|---|
| 676 | ( gg - cc ) * diss(k,j+1,i) + & |
|---|
| 677 | ( gg - dd ) * diss(k,j+1,i+1) & |
|---|
| 678 | ) / ( 3.0_wp * gg ) |
|---|
| 679 | |
|---|
| 680 | IF ( k == nzt ) THEN |
|---|
| 681 | diss_int(n) = diss_int_l |
|---|
| 682 | ELSE |
|---|
| 683 | diss_int_u = ( ( gg - aa ) * diss(k+1,j,i) + & |
|---|
| 684 | ( gg - bb ) * diss(k+1,j,i+1) + & |
|---|
| 685 | ( gg - cc ) * diss(k+1,j+1,i) + & |
|---|
| 686 | ( gg - dd ) * diss(k+1,j+1,i+1) & |
|---|
| 687 | ) / ( 3.0_wp * gg ) |
|---|
| 688 | diss_int(n) = diss_int_l + ( zv(n) - zu(k) ) / dz * & |
|---|
| 689 | ( diss_int_u - diss_int_l ) |
|---|
| 690 | ENDIF |
|---|
| 691 | |
|---|
| 692 | ! |
|---|
| 693 | !-- Set flag for stochastic equation. |
|---|
| 694 | term_1_2(n) = 1.0_wp |
|---|
| 695 | ENDDO |
|---|
| 696 | ENDIF |
|---|
| 697 | ENDDO |
|---|
| 698 | |
|---|
| 699 | DO nb = 0,7 |
|---|
| 700 | i = ip + block_offset(nb)%i_off |
|---|
| 701 | j = jp + block_offset(nb)%j_off |
|---|
| 702 | k = kp + block_offset(nb)%k_off |
|---|
| 703 | |
|---|
| 704 | DO n = start_index(nb), end_index(nb) |
|---|
| 705 | ! |
|---|
| 706 | !-- Vertical interpolation of the horizontally averaged SGS TKE and |
|---|
| 707 | !-- resolved-scale velocity variances and use the interpolated values |
|---|
| 708 | !-- to calculate the coefficient fs, which is a measure of the ratio |
|---|
| 709 | !-- of the subgrid-scale turbulent kinetic energy to the total amount |
|---|
| 710 | !-- of turbulent kinetic energy. |
|---|
| 711 | IF ( k == 0 ) THEN |
|---|
| 712 | e_mean_int = hom(0,1,8,0) |
|---|
| 713 | ELSE |
|---|
| 714 | e_mean_int = hom(k,1,8,0) + & |
|---|
| 715 | ( hom(k+1,1,8,0) - hom(k,1,8,0) ) / & |
|---|
| 716 | ( zu(k+1) - zu(k) ) * & |
|---|
| 717 | ( zv(n) - zu(k) ) |
|---|
| 718 | ENDIF |
|---|
| 719 | |
|---|
| 720 | kw = kp - 1 |
|---|
| 721 | |
|---|
| 722 | IF ( k == 0 ) THEN |
|---|
| 723 | aa = hom(k+1,1,30,0) * ( zv(n) / & |
|---|
| 724 | ( 0.5_wp * ( zu(k+1) - zu(k) ) ) ) |
|---|
| 725 | bb = hom(k+1,1,31,0) * ( zv(n) / & |
|---|
| 726 | ( 0.5_wp * ( zu(k+1) - zu(k) ) ) ) |
|---|
| 727 | cc = hom(kw+1,1,32,0) * ( zv(n) / & |
|---|
| 728 | ( 1.0_wp * ( zw(kw+1) - zw(kw) ) ) ) |
|---|
| 729 | ELSE |
|---|
| 730 | aa = hom(k,1,30,0) + ( hom(k+1,1,30,0) - hom(k,1,30,0) ) * & |
|---|
| 731 | ( ( zv(n) - zu(k) ) / ( zu(k+1) - zu(k) ) ) |
|---|
| 732 | bb = hom(k,1,31,0) + ( hom(k+1,1,31,0) - hom(k,1,31,0) ) * & |
|---|
| 733 | ( ( zv(n) - zu(k) ) / ( zu(k+1) - zu(k) ) ) |
|---|
| 734 | cc = hom(kw,1,32,0) + ( hom(kw+1,1,32,0)-hom(kw,1,32,0) ) * & |
|---|
| 735 | ( ( zv(n) - zw(kw) ) / ( zw(kw+1)-zw(kw) ) ) |
|---|
| 736 | ENDIF |
|---|
| 737 | |
|---|
| 738 | vv_int = ( 1.0_wp / 3.0_wp ) * ( aa + bb + cc ) |
|---|
| 739 | ! |
|---|
| 740 | !-- Needed to avoid NaN particle velocities. The value of 1.0 is just |
|---|
| 741 | !-- an educated guess for the given case. |
|---|
| 742 | IF ( vv_int + ( 2.0_wp / 3.0_wp ) * e_mean_int == 0.0_wp ) THEN |
|---|
| 743 | fs_int(n) = 1.0_wp |
|---|
| 744 | ELSE |
|---|
| 745 | fs_int(n) = ( 2.0_wp / 3.0_wp ) * e_mean_int / & |
|---|
| 746 | ( vv_int + ( 2.0_wp / 3.0_wp ) * e_mean_int ) |
|---|
| 747 | ENDIF |
|---|
| 748 | |
|---|
| 749 | ENDDO |
|---|
| 750 | ENDDO |
|---|
| 751 | |
|---|
| 752 | DO nb = 0, 7 |
|---|
| 753 | DO n = start_index(nb), end_index(nb) |
|---|
| 754 | rg(n,1) = random_gauss( iran_part, 5.0_wp ) |
|---|
| 755 | rg(n,2) = random_gauss( iran_part, 5.0_wp ) |
|---|
| 756 | rg(n,3) = random_gauss( iran_part, 5.0_wp ) |
|---|
| 757 | ENDDO |
|---|
| 758 | ENDDO |
|---|
| 759 | |
|---|
| 760 | DO nb = 0, 7 |
|---|
| 761 | DO n = start_index(nb), end_index(nb) |
|---|
| 762 | |
|---|
| 763 | ! |
|---|
| 764 | !-- Calculate the Lagrangian timescale according to Weil et al. (2004). |
|---|
| 765 | lagr_timescale = ( 4.0_wp * e_int(n) + 1E-20_wp ) / & |
|---|
| 766 | ( 3.0_wp * fs_int(n) * c_0 * diss_int(n) + 1E-20_wp ) |
|---|
| 767 | |
|---|
| 768 | ! |
|---|
| 769 | !-- Calculate the next particle timestep. dt_gap is the time needed to |
|---|
| 770 | !-- complete the current LES timestep. |
|---|
| 771 | dt_gap = dt_3d - particles(n)%dt_sum |
|---|
| 772 | dt_particle(n) = MIN( dt_3d, 0.025_wp * lagr_timescale, dt_gap ) |
|---|
| 773 | |
|---|
| 774 | ! |
|---|
| 775 | !-- The particle timestep should not be too small in order to prevent |
|---|
| 776 | !-- the number of particle timesteps of getting too large |
|---|
| 777 | IF ( dt_particle(n) < dt_min_part .AND. dt_min_part < dt_gap ) THEN |
|---|
| 778 | dt_particle(n) = dt_min_part |
|---|
| 779 | ENDIF |
|---|
| 780 | |
|---|
| 781 | ! |
|---|
| 782 | !-- Calculate the SGS velocity components |
|---|
| 783 | IF ( particles(n)%age == 0.0_wp ) THEN |
|---|
| 784 | ! |
|---|
| 785 | !-- For new particles the SGS components are derived from the SGS |
|---|
| 786 | !-- TKE. Limit the Gaussian random number to the interval |
|---|
| 787 | !-- [-5.0*sigma, 5.0*sigma] in order to prevent the SGS velocities |
|---|
| 788 | !-- from becoming unrealistically large. |
|---|
| 789 | particles(n)%rvar1 = SQRT( 2.0_wp * sgs_wf_part * e_int(n) & |
|---|
| 790 | + 1E-20_wp ) * & |
|---|
| 791 | ( rg(n,1) - 1.0_wp ) |
|---|
| 792 | particles(n)%rvar2 = SQRT( 2.0_wp * sgs_wf_part * e_int(n) & |
|---|
| 793 | + 1E-20_wp ) * & |
|---|
| 794 | ( rg(n,2) - 1.0_wp ) |
|---|
| 795 | particles(n)%rvar3 = SQRT( 2.0_wp * sgs_wf_part * e_int(n) & |
|---|
| 796 | + 1E-20_wp ) * & |
|---|
| 797 | ( rg(n,3) - 1.0_wp ) |
|---|
| 798 | |
|---|
| 799 | ELSE |
|---|
| 800 | ! |
|---|
| 801 | !-- Restriction of the size of the new timestep: compared to the |
|---|
| 802 | !-- previous timestep the increase must not exceed 200%. First, |
|---|
| 803 | !-- check if age > age_m, in order to prevent that particles get zero |
|---|
| 804 | !-- timestep. |
|---|
| 805 | dt_particle_m = MERGE( dt_particle(n), & |
|---|
| 806 | particles(n)%age - particles(n)%age_m, & |
|---|
| 807 | particles(n)%age - particles(n)%age_m < & |
|---|
| 808 | 1E-8_wp ) |
|---|
| 809 | IF ( dt_particle(n) > 2.0_wp * dt_particle_m ) THEN |
|---|
| 810 | dt_particle(n) = 2.0_wp * dt_particle_m |
|---|
| 811 | ENDIF |
|---|
| 812 | |
|---|
| 813 | ! |
|---|
| 814 | !-- For old particles the SGS components are correlated with the |
|---|
| 815 | !-- values from the previous timestep. Random numbers have also to |
|---|
| 816 | !-- be limited (see above). |
|---|
| 817 | !-- As negative values for the subgrid TKE are not allowed, the |
|---|
| 818 | !-- change of the subgrid TKE with time cannot be smaller than |
|---|
| 819 | !-- -e_int(n)/dt_particle. This value is used as a lower boundary |
|---|
| 820 | !-- value for the change of TKE |
|---|
| 821 | de_dt_min = - e_int(n) / dt_particle(n) |
|---|
| 822 | |
|---|
| 823 | de_dt = ( e_int(n) - particles(n)%e_m ) / dt_particle_m |
|---|
| 824 | |
|---|
| 825 | IF ( de_dt < de_dt_min ) THEN |
|---|
| 826 | de_dt = de_dt_min |
|---|
| 827 | ENDIF |
|---|
| 828 | |
|---|
| 829 | CALL weil_stochastic_eq(particles(n)%rvar1, fs_int(n), e_int(n),& |
|---|
| 830 | de_dx_int(n), de_dt, diss_int(n), & |
|---|
| 831 | dt_particle(n), rg(n,1), term_1_2(n) ) |
|---|
| 832 | |
|---|
| 833 | CALL weil_stochastic_eq(particles(n)%rvar2, fs_int(n), e_int(n),& |
|---|
| 834 | de_dy_int(n), de_dt, diss_int(n), & |
|---|
| 835 | dt_particle(n), rg(n,2), term_1_2(n) ) |
|---|
| 836 | |
|---|
| 837 | CALL weil_stochastic_eq(particles(n)%rvar3, fs_int(n), e_int(n),& |
|---|
| 838 | de_dz_int(n), de_dt, diss_int(n), & |
|---|
| 839 | dt_particle(n), rg(n,3), term_1_2(n) ) |
|---|
| 840 | |
|---|
| 841 | ENDIF |
|---|
| 842 | |
|---|
| 843 | u_int(n) = u_int(n) + particles(n)%rvar1 |
|---|
| 844 | v_int(n) = v_int(n) + particles(n)%rvar2 |
|---|
| 845 | w_int(n) = w_int(n) + particles(n)%rvar3 |
|---|
| 846 | ! |
|---|
| 847 | !-- Store the SGS TKE of the current timelevel which is needed for |
|---|
| 848 | !-- for calculating the SGS particle velocities at the next timestep |
|---|
| 849 | particles(n)%e_m = e_int(n) |
|---|
| 850 | ENDDO |
|---|
| 851 | ENDDO |
|---|
| 852 | |
|---|
| 853 | ELSE |
|---|
| 854 | ! |
|---|
| 855 | !-- If no SGS velocities are used, only the particle timestep has to |
|---|
| 856 | !-- be set |
|---|
| 857 | dt_particle = dt_3d |
|---|
| 858 | |
|---|
| 859 | ENDIF |
|---|
| 860 | |
|---|
| 861 | dens_ratio = particle_groups(particles(1:number_of_particles)%group)%density_ratio |
|---|
| 862 | |
|---|
| 863 | IF ( ANY( dens_ratio == 0.0_wp ) ) THEN |
|---|
| 864 | DO nb = 0, 7 |
|---|
| 865 | DO n = start_index(nb), end_index(nb) |
|---|
| 866 | |
|---|
| 867 | ! |
|---|
| 868 | !-- Particle advection |
|---|
| 869 | IF ( dens_ratio(n) == 0.0_wp ) THEN |
|---|
| 870 | ! |
|---|
| 871 | !-- Pure passive transport (without particle inertia) |
|---|
| 872 | particles(n)%x = xv(n) + u_int(n) * dt_particle(n) |
|---|
| 873 | particles(n)%y = yv(n) + v_int(n) * dt_particle(n) |
|---|
| 874 | particles(n)%z = zv(n) + w_int(n) * dt_particle(n) |
|---|
| 875 | |
|---|
| 876 | particles(n)%speed_x = u_int(n) |
|---|
| 877 | particles(n)%speed_y = v_int(n) |
|---|
| 878 | particles(n)%speed_z = w_int(n) |
|---|
| 879 | |
|---|
| 880 | ELSE |
|---|
| 881 | ! |
|---|
| 882 | !-- Transport of particles with inertia |
|---|
| 883 | particles(n)%x = particles(n)%x + particles(n)%speed_x * & |
|---|
| 884 | dt_particle(n) |
|---|
| 885 | particles(n)%y = particles(n)%y + particles(n)%speed_y * & |
|---|
| 886 | dt_particle(n) |
|---|
| 887 | particles(n)%z = particles(n)%z + particles(n)%speed_z * & |
|---|
| 888 | dt_particle(n) |
|---|
| 889 | |
|---|
| 890 | ! |
|---|
| 891 | !-- Update of the particle velocity |
|---|
| 892 | IF ( cloud_droplets ) THEN |
|---|
| 893 | ! |
|---|
| 894 | !-- Terminal velocity is computed for vertical direction (Rogers et |
|---|
| 895 | !-- al., 1993, J. Appl. Meteorol.) |
|---|
| 896 | diameter = particles(n)%radius * 2000.0_wp !diameter in mm |
|---|
| 897 | IF ( diameter <= d0_rog ) THEN |
|---|
| 898 | w_s = k_cap_rog * diameter * ( 1.0_wp - EXP( -k_low_rog * diameter ) ) |
|---|
| 899 | ELSE |
|---|
| 900 | w_s = a_rog - b_rog * EXP( -c_rog * diameter ) |
|---|
| 901 | ENDIF |
|---|
| 902 | |
|---|
| 903 | ! |
|---|
| 904 | !-- If selected, add random velocities following Soelch and Kaercher |
|---|
| 905 | !-- (2010, Q. J. R. Meteorol. Soc.) |
|---|
| 906 | IF ( use_sgs_for_particles ) THEN |
|---|
| 907 | lagr_timescale = km(kp,jp,ip) / MAX( e(kp,jp,ip), 1.0E-20_wp ) |
|---|
| 908 | RL = EXP( -1.0_wp * dt_3d / lagr_timescale ) |
|---|
| 909 | sigma = SQRT( e(kp,jp,ip) ) |
|---|
| 910 | |
|---|
| 911 | rg1 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
|---|
| 912 | rg2 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
|---|
| 913 | rg3 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
|---|
| 914 | |
|---|
| 915 | particles(n)%rvar1 = RL * particles(n)%rvar1 + & |
|---|
| 916 | SQRT( 1.0_wp - RL**2 ) * sigma * rg1 |
|---|
| 917 | particles(n)%rvar2 = RL * particles(n)%rvar2 + & |
|---|
| 918 | SQRT( 1.0_wp - RL**2 ) * sigma * rg2 |
|---|
| 919 | particles(n)%rvar3 = RL * particles(n)%rvar3 + & |
|---|
| 920 | SQRT( 1.0_wp - RL**2 ) * sigma * rg3 |
|---|
| 921 | |
|---|
| 922 | particles(n)%speed_x = u_int(n) + particles(n)%rvar1 |
|---|
| 923 | particles(n)%speed_y = v_int(n) + particles(n)%rvar2 |
|---|
| 924 | particles(n)%speed_z = w_int(n) + particles(n)%rvar3 - w_s |
|---|
| 925 | ELSE |
|---|
| 926 | particles(n)%speed_x = u_int(n) |
|---|
| 927 | particles(n)%speed_y = v_int(n) |
|---|
| 928 | particles(n)%speed_z = w_int(n) - w_s |
|---|
| 929 | ENDIF |
|---|
| 930 | |
|---|
| 931 | ELSE |
|---|
| 932 | |
|---|
| 933 | IF ( use_sgs_for_particles ) THEN |
|---|
| 934 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
|---|
| 935 | exp_term = EXP( -exp_arg * dt_particle(n) ) |
|---|
| 936 | ELSE |
|---|
| 937 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
|---|
| 938 | exp_term = particle_groups(particles(n)%group)%exp_term |
|---|
| 939 | ENDIF |
|---|
| 940 | particles(n)%speed_x = particles(n)%speed_x * exp_term + & |
|---|
| 941 | u_int(n) * ( 1.0_wp - exp_term ) |
|---|
| 942 | particles(n)%speed_y = particles(n)%speed_y * exp_term + & |
|---|
| 943 | v_int(n) * ( 1.0_wp - exp_term ) |
|---|
| 944 | particles(n)%speed_z = particles(n)%speed_z * exp_term + & |
|---|
| 945 | ( w_int(n) - ( 1.0_wp - dens_ratio(n) ) * & |
|---|
| 946 | g / exp_arg ) * ( 1.0_wp - exp_term ) |
|---|
| 947 | ENDIF |
|---|
| 948 | |
|---|
| 949 | ENDIF |
|---|
| 950 | ENDDO |
|---|
| 951 | ENDDO |
|---|
| 952 | |
|---|
| 953 | ELSE |
|---|
| 954 | |
|---|
| 955 | DO nb = 0, 7 |
|---|
| 956 | DO n = start_index(nb), end_index(nb) |
|---|
| 957 | ! |
|---|
| 958 | !-- Transport of particles with inertia |
|---|
| 959 | particles(n)%x = xv(n) + particles(n)%speed_x * dt_particle(n) |
|---|
| 960 | particles(n)%y = yv(n) + particles(n)%speed_y * dt_particle(n) |
|---|
| 961 | particles(n)%z = zv(n) + particles(n)%speed_z * dt_particle(n) |
|---|
| 962 | ! |
|---|
| 963 | !-- Update of the particle velocity |
|---|
| 964 | IF ( cloud_droplets ) THEN |
|---|
| 965 | ! |
|---|
| 966 | !-- Terminal velocity is computed for vertical direction (Rogers et al., |
|---|
| 967 | !-- 1993, J. Appl. Meteorol.) |
|---|
| 968 | diameter = particles(n)%radius * 2000.0_wp !diameter in mm |
|---|
| 969 | IF ( diameter <= d0_rog ) THEN |
|---|
| 970 | w_s = k_cap_rog * diameter * ( 1.0_wp - EXP( -k_low_rog * diameter ) ) |
|---|
| 971 | ELSE |
|---|
| 972 | w_s = a_rog - b_rog * EXP( -c_rog * diameter ) |
|---|
| 973 | ENDIF |
|---|
| 974 | |
|---|
| 975 | ! |
|---|
| 976 | !-- If selected, add random velocities following Soelch and Kaercher |
|---|
| 977 | !-- (2010, Q. J. R. Meteorol. Soc.) |
|---|
| 978 | IF ( use_sgs_for_particles ) THEN |
|---|
| 979 | lagr_timescale = km(kp,jp,ip) / MAX( e(kp,jp,ip), 1.0E-20_wp ) |
|---|
| 980 | RL = EXP( -1.0_wp * dt_3d / lagr_timescale ) |
|---|
| 981 | sigma = SQRT( e(kp,jp,ip) ) |
|---|
| 982 | |
|---|
| 983 | rg1 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
|---|
| 984 | rg2 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
|---|
| 985 | rg3 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
|---|
| 986 | |
|---|
| 987 | particles(n)%rvar1 = RL * particles(n)%rvar1 + & |
|---|
| 988 | SQRT( 1.0_wp - RL**2 ) * sigma * rg1 |
|---|
| 989 | particles(n)%rvar2 = RL * particles(n)%rvar2 + & |
|---|
| 990 | SQRT( 1.0_wp - RL**2 ) * sigma * rg2 |
|---|
| 991 | particles(n)%rvar3 = RL * particles(n)%rvar3 + & |
|---|
| 992 | SQRT( 1.0_wp - RL**2 ) * sigma * rg3 |
|---|
| 993 | |
|---|
| 994 | particles(n)%speed_x = u_int(n) + particles(n)%rvar1 |
|---|
| 995 | particles(n)%speed_y = v_int(n) + particles(n)%rvar2 |
|---|
| 996 | particles(n)%speed_z = w_int(n) + particles(n)%rvar3 - w_s |
|---|
| 997 | ELSE |
|---|
| 998 | particles(n)%speed_x = u_int(n) |
|---|
| 999 | particles(n)%speed_y = v_int(n) |
|---|
| 1000 | particles(n)%speed_z = w_int(n) - w_s |
|---|
| 1001 | ENDIF |
|---|
| 1002 | |
|---|
| 1003 | ELSE |
|---|
| 1004 | |
|---|
| 1005 | IF ( use_sgs_for_particles ) THEN |
|---|
| 1006 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
|---|
| 1007 | exp_term = EXP( -exp_arg * dt_particle(n) ) |
|---|
| 1008 | ELSE |
|---|
| 1009 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
|---|
| 1010 | exp_term = particle_groups(particles(n)%group)%exp_term |
|---|
| 1011 | ENDIF |
|---|
| 1012 | particles(n)%speed_x = particles(n)%speed_x * exp_term + & |
|---|
| 1013 | u_int(n) * ( 1.0_wp - exp_term ) |
|---|
| 1014 | particles(n)%speed_y = particles(n)%speed_y * exp_term + & |
|---|
| 1015 | v_int(n) * ( 1.0_wp - exp_term ) |
|---|
| 1016 | particles(n)%speed_z = particles(n)%speed_z * exp_term + & |
|---|
| 1017 | ( w_int(n) - ( 1.0_wp - dens_ratio(n) ) * g / & |
|---|
| 1018 | exp_arg ) * ( 1.0_wp - exp_term ) |
|---|
| 1019 | ENDIF |
|---|
| 1020 | ENDDO |
|---|
| 1021 | ENDDO |
|---|
| 1022 | |
|---|
| 1023 | ENDIF |
|---|
| 1024 | |
|---|
| 1025 | ! |
|---|
| 1026 | !-- Store the old age of the particle ( needed to prevent that a |
|---|
| 1027 | !-- particle crosses several PEs during one timestep, and for the |
|---|
| 1028 | !-- evaluation of the subgrid particle velocity fluctuations ) |
|---|
| 1029 | particles(1:number_of_particles)%age_m = particles(1:number_of_particles)%age |
|---|
| 1030 | |
|---|
| 1031 | DO nb = 0, 7 |
|---|
| 1032 | DO n = start_index(nb), end_index(nb) |
|---|
| 1033 | ! |
|---|
| 1034 | !-- Increment the particle age and the total time that the particle |
|---|
| 1035 | !-- has advanced within the particle timestep procedure |
|---|
| 1036 | particles(n)%age = particles(n)%age + dt_particle(n) |
|---|
| 1037 | particles(n)%dt_sum = particles(n)%dt_sum + dt_particle(n) |
|---|
| 1038 | |
|---|
| 1039 | ! |
|---|
| 1040 | !-- Check whether there is still a particle that has not yet completed |
|---|
| 1041 | !-- the total LES timestep |
|---|
| 1042 | IF ( ( dt_3d - particles(n)%dt_sum ) > 1E-8_wp ) THEN |
|---|
| 1043 | dt_3d_reached_l = .FALSE. |
|---|
| 1044 | ENDIF |
|---|
| 1045 | |
|---|
| 1046 | ENDDO |
|---|
| 1047 | ENDDO |
|---|
| 1048 | |
|---|
| 1049 | CALL cpu_log( log_point_s(44), 'lpm_advec', 'pause' ) |
|---|
| 1050 | |
|---|
| 1051 | |
|---|
| 1052 | END SUBROUTINE lpm_advec |
|---|
| 1053 | |
|---|
| 1054 | ! Description: |
|---|
| 1055 | ! ------------ |
|---|
| 1056 | !> Calculation of subgrid-scale particle speed using the stochastic model |
|---|
| 1057 | !> of Weil et al. (2004, JAS, 61, 2877-2887). |
|---|
| 1058 | !------------------------------------------------------------------------------! |
|---|
| 1059 | SUBROUTINE weil_stochastic_eq( v_sgs, fs_n, e_n, dedxi_n, dedt_n, diss_n, & |
|---|
| 1060 | dt_n, rg_n, fac ) |
|---|
| 1061 | |
|---|
| 1062 | USE kinds |
|---|
| 1063 | |
|---|
| 1064 | USE particle_attributes, & |
|---|
| 1065 | ONLY: c_0, sgs_wf_part |
|---|
| 1066 | |
|---|
| 1067 | IMPLICIT NONE |
|---|
| 1068 | |
|---|
| 1069 | REAL(wp) :: a1 !< dummy argument |
|---|
| 1070 | REAL(wp) :: dedt_n !< time derivative of TKE at particle position |
|---|
| 1071 | REAL(wp) :: dedxi_n !< horizontal derivative of TKE at particle position |
|---|
| 1072 | REAL(wp) :: diss_n !< dissipation at particle position |
|---|
| 1073 | REAL(wp) :: dt_n !< particle timestep |
|---|
| 1074 | REAL(wp) :: e_n !< TKE at particle position |
|---|
| 1075 | REAL(wp) :: fac !< flag to identify adjacent topography |
|---|
| 1076 | REAL(wp) :: fs_n !< weighting factor to prevent that subgrid-scale particle speed becomes too large |
|---|
| 1077 | REAL(wp) :: sgs_w !< constant (1/3) |
|---|
| 1078 | REAL(wp) :: rg_n !< random number |
|---|
| 1079 | REAL(wp) :: term1 !< memory term |
|---|
| 1080 | REAL(wp) :: term2 !< drift correction term |
|---|
| 1081 | REAL(wp) :: term3 !< random term |
|---|
| 1082 | REAL(wp) :: v_sgs !< subgrid-scale velocity component |
|---|
| 1083 | |
|---|
| 1084 | !-- At first, limit TKE to a small non-zero number, in order to prevent |
|---|
| 1085 | !-- the occurrence of extremely large SGS-velocities in case TKE is zero, |
|---|
| 1086 | !-- (could occur at the simulation begin). |
|---|
| 1087 | e_n = MAX( e_n, 1E-20_wp ) |
|---|
| 1088 | ! |
|---|
| 1089 | !-- Please note, terms 1 and 2 (drift and memory term, respectively) are |
|---|
| 1090 | !-- multiplied by a flag to switch of both terms near topography. |
|---|
| 1091 | !-- This is necessary, as both terms may cause a subgrid-scale velocity build up |
|---|
| 1092 | !-- if particles are trapped in regions with very small TKE, e.g. in narrow street |
|---|
| 1093 | !-- canyons resolved by only a few grid points. Hence, term 1 and term 2 are |
|---|
| 1094 | !-- disabled if one of the adjacent grid points belongs to topography. |
|---|
| 1095 | !-- Moreover, in this case, the previous subgrid-scale component is also set |
|---|
| 1096 | !-- to zero. |
|---|
| 1097 | |
|---|
| 1098 | a1 = fs_n * c_0 * diss_n |
|---|
| 1099 | ! |
|---|
| 1100 | !-- Memory term |
|---|
| 1101 | term1 = - a1 * v_sgs * dt_n / ( 4.0_wp * sgs_wf_part * e_n + 1E-20_wp ) & |
|---|
| 1102 | * fac |
|---|
| 1103 | ! |
|---|
| 1104 | !-- Drift correction term |
|---|
| 1105 | term2 = ( ( dedt_n * v_sgs / e_n ) + dedxi_n ) * 0.5_wp * dt_n & |
|---|
| 1106 | * fac |
|---|
| 1107 | ! |
|---|
| 1108 | !-- Random term |
|---|
| 1109 | term3 = SQRT( MAX( a1, 1E-20 ) ) * ( rg_n - 1.0_wp ) * SQRT( dt_n ) |
|---|
| 1110 | ! |
|---|
| 1111 | !-- In cese one of the adjacent grid-boxes belongs to topograhy, the previous |
|---|
| 1112 | !-- subgrid-scale velocity component is set to zero, in order to prevent a |
|---|
| 1113 | !-- velocity build-up. |
|---|
| 1114 | !-- This case, set also previous subgrid-scale component to zero. |
|---|
| 1115 | v_sgs = v_sgs * fac + term1 + term2 + term3 |
|---|
| 1116 | |
|---|
| 1117 | END SUBROUTINE weil_stochastic_eq |
|---|
