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 hoffmann $ |
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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 |
---|
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 & |
---|
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 | |
---|
474 | ! |
---|
475 | !-- Check if collected particles provide enough LWC for |
---|
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 | |
---|
479 | delta_r = ( ( sl_r3/particles(n)%weight_factor ) & |
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480 | + particles(n)%radius**3 )**( 1./3. ) & |
---|
481 | - particles(n)%radius |
---|
482 | |
---|
483 | DO is = n-1, psi, -1 |
---|
484 | IF ( particles(is)%radius < & |
---|
485 | particles(n)%radius ) THEN |
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486 | particles(is)%weight_factor = 0.0 |
---|
487 | particle_mask(is) = .FALSE. |
---|
488 | deleted_particles = deleted_particles + 1 |
---|
489 | ENDIF |
---|
490 | ENDDO |
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491 | |
---|
492 | ELSE IF ( delta_v < sl_r3 .AND. sl_r3 > 0.0 ) THEN |
---|
493 | |
---|
494 | DO is = n-1, psi, -1 |
---|
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 & |
---|
499 | * ( particles(is)%radius**3 ) ) & |
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500 | - ( delta_v & |
---|
501 | * particles(is)%weight_factor & |
---|
502 | * ( particles(is)%radius**3 ) & |
---|
503 | / sl_r3 ) ) & |
---|
504 | / ( particles(is)%radius**3 ) |
---|
505 | |
---|
506 | IF ( particles(is)%weight_factor < 0.0 ) THEN |
---|
507 | WRITE( message_string, * ) 'negative ', & |
---|
508 | 'weighting factor: ', & |
---|
509 | particles(is)%weight_factor |
---|
510 | CALL message( 'lpm_droplet_collision', & |
---|
511 | 'PA0039', & |
---|
512 | 2, 2, -1, 6, 1 ) |
---|
513 | ENDIF |
---|
514 | ENDIF |
---|
515 | ENDDO |
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516 | |
---|
517 | ENDIF |
---|
518 | |
---|
519 | particles(n)%radius = particles(n)%radius + delta_r |
---|
520 | ql_vp(k,j,i) = ql_vp(k,j,i) + & |
---|
521 | particles(n)%weight_factor * & |
---|
522 | ( particles(n)%radius**3 ) |
---|
523 | ENDDO |
---|
524 | |
---|
525 | ql_vp(k,j,i) = ql_vp(k,j,i) + particles(psi)%weight_factor & |
---|
526 | * particles(psi)%radius**3 |
---|
527 | |
---|
528 | ENDIF ! collision kernel |
---|
529 | |
---|
530 | ELSE IF ( prt_count(k,j,i) == 1 ) THEN |
---|
531 | |
---|
532 | psi = prt_start_index(k,j,i) |
---|
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 |
---|