| 1 | SUBROUTINE lpm_droplet_collision |
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| 2 | |
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| 3 | !--------------------------------------------------------------------------------! |
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| 4 | ! This file is part of PALM. |
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| 5 | ! |
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| 6 | ! PALM is free software: you can redistribute it and/or modify it under the terms |
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| 7 | ! of the GNU General Public License as published by the Free Software Foundation, |
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| 8 | ! either version 3 of the License, or (at your option) any later version. |
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| 9 | ! |
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| 10 | ! PALM is distributed in the hope that it will be useful, but WITHOUT ANY |
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| 11 | ! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR |
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| 12 | ! A PARTICULAR PURPOSE. See the GNU General Public License for more details. |
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| 13 | ! |
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| 14 | ! You should have received a copy of the GNU General Public License along with |
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| 15 | ! PALM. If not, see <http://www.gnu.org/licenses/>. |
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| 16 | ! |
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| 17 | ! Copyright 1997-2012 Leibniz University Hannover |
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| 18 | !--------------------------------------------------------------------------------! |
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| 19 | ! |
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| 20 | ! Current revisions: |
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| 21 | ! ------------------ |
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| 22 | ! |
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| 23 | ! |
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| 24 | ! Former revisions: |
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| 25 | ! ----------------- |
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| 26 | ! $Id: lpm_droplet_collision.f90 1072 2012-11-29 17:04:39Z raasch $ |
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| 27 | ! |
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| 28 | ! 1071 2012-11-29 16:54:55Z franke |
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| 29 | ! Calculation of Hall and Wang kernel now uses collision-coalescence formulation |
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| 30 | ! proposed by Wang instead of the continuous collection equation (for more |
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| 31 | ! information about new method see PALM documentation) |
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| 32 | ! Bugfix: message identifiers added |
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| 33 | ! |
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| 34 | ! 1036 2012-10-22 13:43:42Z raasch |
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| 35 | ! code put under GPL (PALM 3.9) |
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| 36 | ! |
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| 37 | ! 849 2012-03-15 10:35:09Z raasch |
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| 38 | ! initial revision (former part of advec_particles) |
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| 39 | ! |
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| 40 | ! |
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| 41 | ! Description: |
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| 42 | ! ------------ |
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| 43 | ! Calculates change in droplet radius by collision. Droplet collision is |
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| 44 | ! calculated for each grid box seperately. Collision is parameterized by |
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| 45 | ! using collision kernels. Three different kernels are available: |
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| 46 | ! PALM kernel: Kernel is approximated using a method from Rogers and |
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| 47 | ! Yau (1989, A Short Course in Cloud Physics, Pergamon Press). |
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| 48 | ! All droplets smaller than the treated one are represented by |
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| 49 | ! one droplet with mean features. Collision efficiencies are taken |
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| 50 | ! from the respective table in Rogers and Yau. |
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| 51 | ! Hall kernel: Kernel from Hall (1980, J. Atmos. Sci., 2486-2507), which |
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| 52 | ! considers collision due to pure gravitational effects. |
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| 53 | ! Wang kernel: Beside gravitational effects (treated with the Hall-kernel) also |
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| 54 | ! the effects of turbulence on the collision are considered using |
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| 55 | ! parameterizations of Ayala et al. (2008, New J. Phys., 10, |
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| 56 | ! 075015) and Wang and Grabowski (2009, Atmos. Sci. Lett., 10, |
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| 57 | ! 1-8). This kernel includes three possible effects of turbulence: |
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| 58 | ! the modification of the relative velocity between the droplets, |
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| 59 | ! the effect of preferential concentration, and the enhancement of |
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| 60 | ! collision efficiencies. |
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| 61 | !------------------------------------------------------------------------------! |
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| 62 | |
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| 63 | USE arrays_3d |
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| 64 | USE cloud_parameters |
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| 65 | USE constants |
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| 66 | USE control_parameters |
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| 67 | USE cpulog |
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| 68 | USE grid_variables |
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| 69 | USE indices |
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| 70 | USE interfaces |
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| 71 | USE lpm_collision_kernels_mod |
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| 72 | USE particle_attributes |
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| 73 | |
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| 74 | IMPLICIT NONE |
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| 75 | |
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| 76 | INTEGER :: eclass, i, ii, inc, is, j, jj, js, k, kk, n, pse, psi, & |
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| 77 | rclass_l, rclass_s |
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| 78 | |
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| 79 | REAL :: aa, bb, cc, dd, delta_r, delta_v, gg, epsilon, integral, lw_max, & |
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| 80 | mean_r, ql_int, ql_int_l, ql_int_u, u_int, u_int_l, u_int_u, & |
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| 81 | v_int, v_int_l, v_int_u, w_int, w_int_l, w_int_u, sl_r3, sl_r4, & |
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| 82 | x, y, sum1, sum2, sum3, r3, ddV |
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| 83 | |
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| 84 | TYPE(particle_type) :: tmp_particle |
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| 85 | REAL, DIMENSION(:), ALLOCATABLE :: rad, weight |
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| 86 | |
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| 87 | |
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| 88 | CALL cpu_log( log_point_s(43), 'lpm_droplet_coll', 'start' ) |
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| 89 | |
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| 90 | DO i = nxl, nxr |
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| 91 | DO j = nys, nyn |
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| 92 | DO k = nzb+1, nzt |
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| 93 | ! |
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| 94 | !-- Collision requires at least two particles in the box |
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| 95 | IF ( prt_count(k,j,i) > 1 ) THEN |
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| 96 | ! |
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| 97 | !-- First, sort particles within the gridbox by their size, |
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| 98 | !-- using Shell's method (see Numerical Recipes) |
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| 99 | !-- NOTE: In case of using particle tails, the re-sorting of |
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| 100 | !-- ---- tails would have to be included here! |
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| 101 | psi = prt_start_index(k,j,i) - 1 |
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| 102 | inc = 1 |
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| 103 | DO WHILE ( inc <= prt_count(k,j,i) ) |
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| 104 | inc = 3 * inc + 1 |
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| 105 | ENDDO |
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| 106 | |
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| 107 | DO WHILE ( inc > 1 ) |
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| 108 | inc = inc / 3 |
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| 109 | DO is = inc+1, prt_count(k,j,i) |
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| 110 | tmp_particle = particles(psi+is) |
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| 111 | js = is |
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| 112 | DO WHILE ( particles(psi+js-inc)%radius > & |
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| 113 | tmp_particle%radius ) |
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| 114 | particles(psi+js) = particles(psi+js-inc) |
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| 115 | js = js - inc |
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| 116 | IF ( js <= inc ) EXIT |
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| 117 | ENDDO |
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| 118 | particles(psi+js) = tmp_particle |
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| 119 | ENDDO |
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| 120 | ENDDO |
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| 121 | |
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| 122 | psi = prt_start_index(k,j,i) |
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| 123 | pse = psi + prt_count(k,j,i)-1 |
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| 124 | |
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| 125 | ! |
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| 126 | !-- Now apply the different kernels |
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| 127 | IF ( ( hall_kernel .OR. wang_kernel ) .AND. & |
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| 128 | use_kernel_tables ) THEN |
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| 129 | ! |
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| 130 | !-- Fast method with pre-calculated efficiencies for |
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| 131 | !-- discrete radius- and dissipation-classes. |
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| 132 | ! |
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| 133 | !-- Determine dissipation class index of this gridbox |
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| 134 | IF ( wang_kernel ) THEN |
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| 135 | eclass = INT( diss(k,j,i) * 1.0E4 / 1000.0 * & |
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| 136 | dissipation_classes ) + 1 |
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| 137 | epsilon = diss(k,j,i) |
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| 138 | ELSE |
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| 139 | epsilon = 0.0 |
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| 140 | ENDIF |
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| 141 | IF ( hall_kernel .OR. epsilon * 1.0E4 < 0.001 ) THEN |
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| 142 | eclass = 0 ! Hall kernel is used |
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| 143 | ELSE |
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| 144 | eclass = MIN( dissipation_classes, eclass ) |
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| 145 | ENDIF |
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| 146 | |
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| 147 | ! |
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| 148 | !-- Droplet collision are calculated using collision-coalescence |
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| 149 | !-- formulation proposed by Wang (see PALM documentation) |
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| 150 | !-- Since new radii after collision are defined by radii of all |
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| 151 | !-- droplets before collision, temporary fields for new radii and |
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| 152 | !-- weighting factors are needed |
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| 153 | ALLOCATE(rad(1:prt_count(k,j,i)), weight(1:prt_count(k,j,i))) |
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| 154 | |
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| 155 | rad = 0.0 |
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| 156 | weight = 0.0 |
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| 157 | |
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| 158 | DO n = psi, pse, 1 |
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| 159 | |
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| 160 | sum1 = 0.0 |
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| 161 | sum2 = 0.0 |
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| 162 | sum3 = 0.0 |
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| 163 | |
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| 164 | rclass_l = particles(n)%class |
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| 165 | ! |
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| 166 | !-- Mass added due to collisions with smaller droplets |
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| 167 | DO is = psi, n-1 |
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| 168 | |
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| 169 | rclass_s = particles(is)%class |
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| 170 | sum1 = sum1 + ( particles(is)%radius**3 * & |
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| 171 | ckernel(rclass_l,rclass_s,eclass) * & |
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| 172 | particles(is)%weight_factor ) |
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| 173 | |
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| 174 | ENDDO |
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| 175 | ! |
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| 176 | !-- Rate of collisions with larger droplets |
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| 177 | DO is = n+1, pse |
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| 178 | |
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| 179 | rclass_s = particles(is)%class |
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| 180 | sum2 = sum2 + ( ckernel(rclass_l,rclass_s,eclass) * & |
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| 181 | particles(is)%weight_factor ) |
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| 182 | |
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| 183 | ENDDO |
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| 184 | |
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| 185 | r3 = particles(n)%radius**3 |
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| 186 | ddV = ddx * ddy / dz |
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| 187 | is = prt_start_index(k,j,i) |
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| 188 | ! |
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| 189 | !-- Change of the current weighting factor |
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| 190 | sum3 = 1 - dt_3d * ddV * & |
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| 191 | ckernel(rclass_l,rclass_l,eclass) * & |
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| 192 | ( particles(n)%weight_factor - 1 ) * 0.5 - & |
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| 193 | dt_3d * ddV * sum2 |
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| 194 | weight(n-is+1) = particles(n)%weight_factor * sum3 |
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| 195 | ! |
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| 196 | !-- Change of the current droplet radius |
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| 197 | rad(n-is+1) = ( (r3 + dt_3d * ddV * (sum1 - sum2 * r3) )/& |
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| 198 | sum3 )**0.33333333333333 |
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| 199 | |
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| 200 | IF ( weight(n-is+1) < 0.0 ) THEN |
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| 201 | WRITE( message_string, * ) 'negative weighting', & |
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| 202 | 'factor: ', weight(n-is+1) |
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| 203 | CALL message( 'lpm_droplet_collision', 'PA0028', & |
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| 204 | 2, 2, -1, 6, 1 ) |
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| 205 | ENDIF |
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| 206 | |
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| 207 | ql_vp(k,j,i) = ql_vp(k,j,i) + weight(n-is+1) & |
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| 208 | * rad(n-is+1)**3 |
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| 209 | |
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| 210 | ENDDO |
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| 211 | |
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| 212 | particles(psi:pse)%radius = rad(1:prt_count(k,j,i)) |
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| 213 | particles(psi:pse)%weight_factor = weight(1:prt_count(k,j,i)) |
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| 214 | |
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| 215 | DEALLOCATE(rad, weight) |
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| 216 | |
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| 217 | ELSEIF ( ( hall_kernel .OR. wang_kernel ) .AND. & |
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| 218 | .NOT. use_kernel_tables ) THEN |
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| 219 | ! |
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| 220 | !-- Collision efficiencies are calculated for every new |
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| 221 | !-- grid box. First, allocate memory for kernel table. |
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| 222 | !-- Third dimension is 1, because table is re-calculated for |
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| 223 | !-- every new dissipation value. |
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| 224 | ALLOCATE( ckernel(prt_start_index(k,j,i): & |
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| 225 | prt_start_index(k,j,i)+prt_count(k,j,i)-1, & |
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| 226 | prt_start_index(k,j,i): & |
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| 227 | prt_start_index(k,j,i)+prt_count(k,j,i)-1,1:1) ) |
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| 228 | ! |
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| 229 | !-- Now calculate collision efficiencies for this box |
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| 230 | CALL recalculate_kernel( i, j, k ) |
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| 231 | |
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| 232 | ! |
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| 233 | !-- Droplet collision are calculated using collision-coalescence |
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| 234 | !-- formulation proposed by Wang (see PALM documentation) |
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| 235 | !-- Since new radii after collision are defined by radii of all |
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| 236 | !-- droplets before collision, temporary fields for new radii and |
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| 237 | !-- weighting factors are needed |
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| 238 | ALLOCATE(rad(1:prt_count(k,j,i)), weight(1:prt_count(k,j,i))) |
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| 239 | |
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| 240 | rad = 0.0 |
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| 241 | weight = 0.0 |
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| 242 | |
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| 243 | DO n = psi, pse, 1 |
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| 244 | |
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| 245 | sum1 = 0.0 |
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| 246 | sum2 = 0.0 |
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| 247 | sum3 = 0.0 |
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| 248 | ! |
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| 249 | !-- Mass added due to collisions with smaller droplets |
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| 250 | DO is = psi, n-1 |
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| 251 | sum1 = sum1 + ( particles(is)%radius**3 * & |
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| 252 | ckernel(n,is,1) * & |
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| 253 | particles(is)%weight_factor ) |
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| 254 | ENDDO |
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| 255 | ! |
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| 256 | !-- Rate of collisions with larger droplets |
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| 257 | DO is = n+1, pse |
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| 258 | sum2 = sum2 + ( ckernel(n,is,1) * & |
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| 259 | particles(is)%weight_factor ) |
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| 260 | ENDDO |
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| 261 | |
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| 262 | r3 = particles(n)%radius**3 |
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| 263 | ddV = ddx * ddy / dz |
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| 264 | is = prt_start_index(k,j,i) |
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| 265 | ! |
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| 266 | !-- Change of the current weighting factor |
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| 267 | sum3 = 1 - dt_3d * ddV * & |
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| 268 | ckernel(n,n,1) * & |
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| 269 | ( particles(n)%weight_factor - 1 ) * 0.5 - & |
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| 270 | dt_3d * ddV * sum2 |
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| 271 | weight(n-is+1) = particles(n)%weight_factor * sum3 |
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| 272 | ! |
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| 273 | !-- Change of the current droplet radius |
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| 274 | rad(n-is+1) = ( (r3 + dt_3d * ddV * (sum1 - sum2 * r3) )/& |
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| 275 | sum3 )**0.33333333333333 |
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| 276 | |
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| 277 | IF ( weight(n-is+1) < 0.0 ) THEN |
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| 278 | WRITE( message_string, * ) 'negative weighting', & |
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| 279 | 'factor: ', weight(n-is+1) |
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| 280 | CALL message( 'lpm_droplet_collision', 'PA0037', & |
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| 281 | 2, 2, -1, 6, 1 ) |
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| 282 | ENDIF |
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| 283 | |
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| 284 | ql_vp(k,j,i) = ql_vp(k,j,i) + weight(n-is+1) & |
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| 285 | * rad(n-is+1)**3 |
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| 286 | |
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| 287 | ENDDO |
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| 288 | |
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| 289 | particles(psi:pse)%radius = rad(1:prt_count(k,j,i)) |
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| 290 | particles(psi:pse)%weight_factor = weight(1:prt_count(k,j,i)) |
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| 291 | |
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| 292 | DEALLOCATE( rad, weight, ckernel ) |
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| 293 | |
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| 294 | ELSEIF ( palm_kernel ) THEN |
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| 295 | ! |
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| 296 | !-- PALM collision kernel |
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| 297 | ! |
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| 298 | !-- Calculate the mean radius of all those particles which |
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| 299 | !-- are of smaller size than the current particle and |
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| 300 | !-- use this radius for calculating the collision efficiency |
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| 301 | DO n = psi+prt_count(k,j,i)-1, psi+1, -1 |
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| 302 | |
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| 303 | sl_r3 = 0.0 |
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| 304 | sl_r4 = 0.0 |
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| 305 | |
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| 306 | DO is = n-1, psi, -1 |
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| 307 | IF ( particles(is)%radius < particles(n)%radius ) & |
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| 308 | THEN |
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| 309 | sl_r3 = sl_r3 + particles(is)%weight_factor & |
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| 310 | * particles(is)%radius**3 |
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| 311 | sl_r4 = sl_r4 + particles(is)%weight_factor & |
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| 312 | * particles(is)%radius**4 |
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| 313 | ENDIF |
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| 314 | ENDDO |
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| 315 | |
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| 316 | IF ( ( sl_r3 ) > 0.0 ) THEN |
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| 317 | mean_r = ( sl_r4 ) / ( sl_r3 ) |
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| 318 | |
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| 319 | CALL collision_efficiency_rogers( mean_r, & |
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| 320 | particles(n)%radius, & |
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| 321 | effective_coll_efficiency ) |
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| 322 | |
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| 323 | ELSE |
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| 324 | effective_coll_efficiency = 0.0 |
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| 325 | ENDIF |
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| 326 | |
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| 327 | IF ( effective_coll_efficiency > 1.0 .OR. & |
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| 328 | effective_coll_efficiency < 0.0 ) & |
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| 329 | THEN |
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| 330 | WRITE( message_string, * ) 'collision_efficien' , & |
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| 331 | 'cy out of range:' ,effective_coll_efficiency |
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| 332 | CALL message( 'lpm_droplet_collision', 'PA0145', 2, & |
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| 333 | 2, -1, 6, 1 ) |
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| 334 | ENDIF |
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| 335 | |
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| 336 | ! |
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| 337 | !-- Interpolation of ... |
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| 338 | ii = particles(n)%x * ddx |
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| 339 | jj = particles(n)%y * ddy |
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| 340 | kk = ( particles(n)%z + 0.5 * dz ) / dz |
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| 341 | |
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| 342 | x = particles(n)%x - ii * dx |
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| 343 | y = particles(n)%y - jj * dy |
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| 344 | aa = x**2 + y**2 |
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| 345 | bb = ( dx - x )**2 + y**2 |
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| 346 | cc = x**2 + ( dy - y )**2 |
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| 347 | dd = ( dx - x )**2 + ( dy - y )**2 |
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| 348 | gg = aa + bb + cc + dd |
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| 349 | |
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| 350 | ql_int_l = ( (gg-aa) * ql(kk,jj,ii) + (gg-bb) * & |
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| 351 | ql(kk,jj,ii+1) & |
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| 352 | + (gg-cc) * ql(kk,jj+1,ii) + ( gg-dd ) * & |
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| 353 | ql(kk,jj+1,ii+1) & |
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| 354 | ) / ( 3.0 * gg ) |
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| 355 | |
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| 356 | ql_int_u = ( (gg-aa) * ql(kk+1,jj,ii) + (gg-bb) * & |
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| 357 | ql(kk+1,jj,ii+1) & |
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| 358 | + (gg-cc) * ql(kk+1,jj+1,ii) + (gg-dd) * & |
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| 359 | ql(kk+1,jj+1,ii+1) & |
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| 360 | ) / ( 3.0 * gg ) |
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| 361 | |
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| 362 | ql_int = ql_int_l + ( particles(n)%z - zu(kk) ) / dz *& |
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| 363 | ( ql_int_u - ql_int_l ) |
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| 364 | |
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| 365 | ! |
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| 366 | !-- Interpolate u velocity-component |
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| 367 | ii = ( particles(n)%x + 0.5 * dx ) * ddx |
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| 368 | jj = particles(n)%y * ddy |
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| 369 | kk = ( particles(n)%z + 0.5 * dz ) / dz ! only if eqist |
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| 370 | |
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| 371 | IF ( ( particles(n)%z - zu(kk) ) > (0.5*dz) ) kk = kk+1 |
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| 372 | |
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| 373 | x = particles(n)%x + ( 0.5 - ii ) * dx |
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| 374 | y = particles(n)%y - jj * dy |
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| 375 | aa = x**2 + y**2 |
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| 376 | bb = ( dx - x )**2 + y**2 |
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| 377 | cc = x**2 + ( dy - y )**2 |
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| 378 | dd = ( dx - x )**2 + ( dy - y )**2 |
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| 379 | gg = aa + bb + cc + dd |
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| 380 | |
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| 381 | u_int_l = ( (gg-aa) * u(kk,jj,ii) + (gg-bb) * & |
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| 382 | u(kk,jj,ii+1) & |
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| 383 | + (gg-cc) * u(kk,jj+1,ii) + (gg-dd) * & |
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| 384 | u(kk,jj+1,ii+1) & |
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| 385 | ) / ( 3.0 * gg ) - u_gtrans |
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| 386 | IF ( kk+1 == nzt+1 ) THEN |
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| 387 | u_int = u_int_l |
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| 388 | ELSE |
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| 389 | u_int_u = ( (gg-aa) * u(kk+1,jj,ii) + (gg-bb) * & |
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| 390 | u(kk+1,jj,ii+1) & |
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| 391 | + (gg-cc) * u(kk+1,jj+1,ii) + (gg-dd) * & |
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| 392 | u(kk+1,jj+1,ii+1) & |
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| 393 | ) / ( 3.0 * gg ) - u_gtrans |
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| 394 | u_int = u_int_l + ( particles(n)%z - zu(kk) ) / dz & |
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| 395 | * ( u_int_u - u_int_l ) |
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| 396 | ENDIF |
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| 397 | |
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| 398 | ! |
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| 399 | !-- Same procedure for interpolation of the v velocity-com- |
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| 400 | !-- ponent (adopt index k from u velocity-component) |
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| 401 | ii = particles(n)%x * ddx |
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| 402 | jj = ( particles(n)%y + 0.5 * dy ) * ddy |
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| 403 | |
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| 404 | x = particles(n)%x - ii * dx |
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| 405 | y = particles(n)%y + ( 0.5 - jj ) * dy |
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| 406 | aa = x**2 + y**2 |
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| 407 | bb = ( dx - x )**2 + y**2 |
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| 408 | cc = x**2 + ( dy - y )**2 |
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| 409 | dd = ( dx - x )**2 + ( dy - y )**2 |
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| 410 | gg = aa + bb + cc + dd |
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| 411 | |
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| 412 | v_int_l = ( ( gg-aa ) * v(kk,jj,ii) + ( gg-bb ) * & |
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| 413 | v(kk,jj,ii+1) & |
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| 414 | + ( gg-cc ) * v(kk,jj+1,ii) + ( gg-dd ) * & |
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| 415 | v(kk,jj+1,ii+1) & |
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| 416 | ) / ( 3.0 * gg ) - v_gtrans |
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| 417 | IF ( kk+1 == nzt+1 ) THEN |
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| 418 | v_int = v_int_l |
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| 419 | ELSE |
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| 420 | v_int_u = ( (gg-aa) * v(kk+1,jj,ii) + (gg-bb) * & |
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| 421 | v(kk+1,jj,ii+1) & |
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| 422 | + (gg-cc) * v(kk+1,jj+1,ii) + (gg-dd) * & |
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| 423 | v(kk+1,jj+1,ii+1) & |
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| 424 | ) / ( 3.0 * gg ) - v_gtrans |
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| 425 | v_int = v_int_l + ( particles(n)%z - zu(kk) ) / dz & |
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| 426 | * ( v_int_u - v_int_l ) |
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| 427 | ENDIF |
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| 428 | |
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| 429 | ! |
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| 430 | !-- Same procedure for interpolation of the w velocity-com- |
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| 431 | !-- ponent (adopt index i from v velocity-component) |
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| 432 | jj = particles(n)%y * ddy |
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| 433 | kk = particles(n)%z / dz |
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| 434 | |
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| 435 | x = particles(n)%x - ii * dx |
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| 436 | y = particles(n)%y - jj * dy |
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| 437 | aa = x**2 + y**2 |
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| 438 | bb = ( dx - x )**2 + y**2 |
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| 439 | cc = x**2 + ( dy - y )**2 |
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| 440 | dd = ( dx - x )**2 + ( dy - y )**2 |
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| 441 | gg = aa + bb + cc + dd |
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| 442 | |
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| 443 | w_int_l = ( ( gg-aa ) * w(kk,jj,ii) + ( gg-bb ) * & |
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| 444 | w(kk,jj,ii+1) & |
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| 445 | + ( gg-cc ) * w(kk,jj+1,ii) + ( gg-dd ) * & |
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| 446 | w(kk,jj+1,ii+1) & |
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| 447 | ) / ( 3.0 * gg ) |
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| 448 | IF ( kk+1 == nzt+1 ) THEN |
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| 449 | w_int = w_int_l |
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| 450 | ELSE |
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| 451 | w_int_u = ( (gg-aa) * w(kk+1,jj,ii) + (gg-bb) * & |
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| 452 | w(kk+1,jj,ii+1) & |
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| 453 | + (gg-cc) * w(kk+1,jj+1,ii) + (gg-dd) * & |
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| 454 | w(kk+1,jj+1,ii+1) & |
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| 455 | ) / ( 3.0 * gg ) |
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| 456 | w_int = w_int_l + ( particles(n)%z - zw(kk) ) / dz & |
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| 457 | * ( w_int_u - w_int_l ) |
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| 458 | ENDIF |
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| 459 | |
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| 460 | ! |
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| 461 | !-- Change in radius due to collision |
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| 462 | delta_r = effective_coll_efficiency / 3.0 & |
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| 463 | * pi * sl_r3 * ddx * ddy / dz & |
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| 464 | * SQRT( ( u_int - particles(n)%speed_x )**2 & |
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| 465 | + ( v_int - particles(n)%speed_y )**2 & |
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| 466 | + ( w_int - particles(n)%speed_z )**2 & |
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| 467 | ) * dt_3d |
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| 468 | ! |
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| 469 | !-- Change in volume due to collision |
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| 470 | delta_v = particles(n)%weight_factor & |
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| 471 | * ( ( particles(n)%radius + delta_r )**3 & |
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| 472 | - particles(n)%radius**3 ) |
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| 473 | |
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| 474 | ! |
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| 475 | !-- Check if collected particles provide enough LWC for |
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| 476 | !-- volume change of collector particle |
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| 477 | IF ( delta_v >= sl_r3 .AND. sl_r3 > 0.0 ) THEN |
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| 478 | |
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| 479 | delta_r = ( ( sl_r3/particles(n)%weight_factor ) & |
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| 480 | + particles(n)%radius**3 )**( 1./3. ) & |
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| 481 | - particles(n)%radius |
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| 482 | |
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| 483 | DO is = n-1, psi, -1 |
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| 484 | IF ( particles(is)%radius < & |
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| 485 | particles(n)%radius ) THEN |
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| 486 | particles(is)%weight_factor = 0.0 |
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| 487 | particle_mask(is) = .FALSE. |
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| 488 | deleted_particles = deleted_particles + 1 |
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| 489 | ENDIF |
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| 490 | ENDDO |
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| 491 | |
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| 492 | ELSE IF ( delta_v < sl_r3 .AND. sl_r3 > 0.0 ) THEN |
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| 493 | |
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| 494 | DO is = n-1, psi, -1 |
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| 495 | IF ( particles(is)%radius < particles(n)%radius & |
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| 496 | .AND. sl_r3 > 0.0 ) THEN |
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| 497 | particles(is)%weight_factor = & |
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| 498 | ( ( particles(is)%weight_factor & |
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| 499 | * ( particles(is)%radius**3 ) ) & |
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| 500 | - ( delta_v & |
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| 501 | * particles(is)%weight_factor & |
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| 502 | * ( particles(is)%radius**3 ) & |
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| 503 | / sl_r3 ) ) & |
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| 504 | / ( particles(is)%radius**3 ) |
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| 505 | |
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| 506 | IF ( particles(is)%weight_factor < 0.0 ) THEN |
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| 507 | WRITE( message_string, * ) 'negative ', & |
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| 508 | 'weighting factor: ', & |
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| 509 | particles(is)%weight_factor |
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| 510 | CALL message( 'lpm_droplet_collision', & |
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| 511 | 'PA0039', & |
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| 512 | 2, 2, -1, 6, 1 ) |
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| 513 | ENDIF |
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| 514 | ENDIF |
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| 515 | ENDDO |
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| 516 | |
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| 517 | ENDIF |
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| 518 | |
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| 519 | particles(n)%radius = particles(n)%radius + delta_r |
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| 520 | ql_vp(k,j,i) = ql_vp(k,j,i) + & |
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| 521 | particles(n)%weight_factor * & |
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| 522 | ( particles(n)%radius**3 ) |
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| 523 | ENDDO |
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| 524 | |
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| 525 | ql_vp(k,j,i) = ql_vp(k,j,i) + particles(psi)%weight_factor & |
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| 526 | * particles(psi)%radius**3 |
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| 527 | |
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| 528 | ENDIF ! collision kernel |
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| 529 | |
|---|
| 530 | ELSE IF ( prt_count(k,j,i) == 1 ) THEN |
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| 531 | |
|---|
| 532 | psi = prt_start_index(k,j,i) |
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| 533 | |
|---|
| 534 | ! |
|---|
| 535 | !-- Calculate change of weighting factor due to self collision |
|---|
| 536 | IF ( ( hall_kernel .OR. wang_kernel ) .AND. & |
|---|
| 537 | use_kernel_tables ) THEN |
|---|
| 538 | |
|---|
| 539 | IF ( wang_kernel ) THEN |
|---|
| 540 | eclass = INT( diss(k,j,i) * 1.0E4 / 1000.0 * & |
|---|
| 541 | dissipation_classes ) + 1 |
|---|
| 542 | epsilon = diss(k,j,i) |
|---|
| 543 | ELSE |
|---|
| 544 | epsilon = 0.0 |
|---|
| 545 | ENDIF |
|---|
| 546 | IF ( hall_kernel .OR. epsilon * 1.0E4 < 0.001 ) THEN |
|---|
| 547 | eclass = 0 ! Hall kernel is used |
|---|
| 548 | ELSE |
|---|
| 549 | eclass = MIN( dissipation_classes, eclass ) |
|---|
| 550 | ENDIF |
|---|
| 551 | |
|---|
| 552 | ddV = ddx * ddy / dz |
|---|
| 553 | rclass_l = particles(psi)%class |
|---|
| 554 | sum3 = 1 - dt_3d * ddV * & |
|---|
| 555 | ( ckernel(rclass_l,rclass_l,eclass) * & |
|---|
| 556 | ( particles(psi)%weight_factor-1 ) * 0.5 ) |
|---|
| 557 | |
|---|
| 558 | particles(psi)%radius = ( particles(psi)%radius**3 / & |
|---|
| 559 | sum3 )**0.33333333333333 |
|---|
| 560 | particles(psi)%weight_factor = particles(psi)%weight_factor & |
|---|
| 561 | * sum3 |
|---|
| 562 | |
|---|
| 563 | ELSE IF ( ( hall_kernel .OR. wang_kernel ) .AND. & |
|---|
| 564 | .NOT. use_kernel_tables ) THEN |
|---|
| 565 | ! |
|---|
| 566 | !-- Collision efficiencies are calculated for every new |
|---|
| 567 | !-- grid box. First, allocate memory for kernel table. |
|---|
| 568 | !-- Third dimension is 1, because table is re-calculated for |
|---|
| 569 | !-- every new dissipation value. |
|---|
| 570 | ALLOCATE( ckernel(psi:psi, psi:psi, 1:1) ) |
|---|
| 571 | ! |
|---|
| 572 | !-- Now calculate collision efficiencies for this box |
|---|
| 573 | CALL recalculate_kernel( i, j, k ) |
|---|
| 574 | |
|---|
| 575 | ddV = ddx * ddy / dz |
|---|
| 576 | sum3 = 1 - dt_3d * ddV * ( ckernel(psi,psi,1) * & |
|---|
| 577 | ( particles(psi)%weight_factor - 1 ) * 0.5 ) |
|---|
| 578 | |
|---|
| 579 | particles(psi)%radius = ( particles(psi)%radius**3 / & |
|---|
| 580 | sum3 )**0.33333333333333 |
|---|
| 581 | particles(psi)%weight_factor = particles(psi)%weight_factor & |
|---|
| 582 | * sum3 |
|---|
| 583 | |
|---|
| 584 | DEALLOCATE( ckernel ) |
|---|
| 585 | ENDIF |
|---|
| 586 | |
|---|
| 587 | ql_vp(k,j,i) = particles(psi)%weight_factor * & |
|---|
| 588 | particles(psi)%radius**3 |
|---|
| 589 | ENDIF |
|---|
| 590 | |
|---|
| 591 | ! |
|---|
| 592 | !-- Check if condensation of LWC was conserved during collision |
|---|
| 593 | !-- process |
|---|
| 594 | IF ( ql_v(k,j,i) /= 0.0 ) THEN |
|---|
| 595 | IF ( ql_vp(k,j,i) / ql_v(k,j,i) >= 1.0001 .OR. & |
|---|
| 596 | ql_vp(k,j,i) / ql_v(k,j,i) <= 0.9999 ) THEN |
|---|
| 597 | WRITE( message_string, * ) 'LWC is not conserved during',& |
|---|
| 598 | ' collision! ', & |
|---|
| 599 | 'LWC after condensation: ', & |
|---|
| 600 | ql_v(k,j,i), & |
|---|
| 601 | ' LWC after collision: ', & |
|---|
| 602 | ql_vp(k,j,i) |
|---|
| 603 | CALL message( 'lpm_droplet_collision', 'PA0040', & |
|---|
| 604 | 2, 2, -1, 6, 1 ) |
|---|
| 605 | ENDIF |
|---|
| 606 | ENDIF |
|---|
| 607 | |
|---|
| 608 | ENDDO |
|---|
| 609 | ENDDO |
|---|
| 610 | ENDDO |
|---|
| 611 | |
|---|
| 612 | CALL cpu_log( log_point_s(43), 'lpm_droplet_coll', 'stop' ) |
|---|
| 613 | |
|---|
| 614 | |
|---|
| 615 | END SUBROUTINE lpm_droplet_collision |
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