!> @file init_advec.f90 !------------------------------------------------------------------------------! ! This file is part of the PALM model system. ! ! PALM is free software: you can redistribute it and/or modify it under the ! terms of the GNU General Public License as published by the Free Software ! Foundation, either version 3 of the License, or (at your option) any later ! version. ! ! PALM is distributed in the hope that it will be useful, but WITHOUT ANY ! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR ! A PARTICULAR PURPOSE. See the GNU General Public License for more details. ! ! You should have received a copy of the GNU General Public License along with ! PALM. If not, see . ! ! Copyright 1997-2019 Leibniz Universitaet Hannover !------------------------------------------------------------------------------! ! ! Current revisions: ! ----------------- ! ! ! Former revisions: ! ----------------- ! $Id: init_advec.f90 4182 2019-08-22 15:20:23Z oliver.maas $ ! Corrected "Former revisions" section ! ! 3655 2019-01-07 16:51:22Z knoop ! Corrected "Former revisions" section ! ! Revision 1.1 1999/02/05 09:07:38 raasch ! Initial revision ! ! ! Description: ! ------------ !> Initialize constant coefficients and parameters for certain advection schemes. !------------------------------------------------------------------------------! SUBROUTINE init_advec USE advection, & ONLY: aex, bex, dex, eex USE kinds USE control_parameters, & ONLY: scalar_advec IMPLICIT NONE INTEGER(iwp) :: i !< INTEGER(iwp) :: intervals !< INTEGER(iwp) :: j !< REAL(wp) :: delt !< REAL(wp) :: dn !< REAL(wp) :: dnneu !< REAL(wp) :: ex1 !< REAL(wp) :: ex2 !< REAL(wp) :: ex3 !< REAL(wp) :: ex4 !< REAL(wp) :: ex5 !< REAL(wp) :: ex6 !< REAL(wp) :: sterm !< IF ( scalar_advec == 'bc-scheme' ) THEN ! !-- Compute exponential coefficients for the Bott-Chlond scheme intervals = 1000 ALLOCATE( aex(intervals), bex(intervals), dex(intervals), eex(intervals) ) delt = 1.0_wp / REAL( intervals, KIND=wp ) sterm = delt * 0.5_wp DO i = 1, intervals IF ( sterm > 0.5_wp ) THEN dn = -5.0_wp ELSE dn = 5.0_wp ENDIF DO j = 1, 15 ex1 = dn * EXP( -dn ) - EXP( 0.5_wp * dn ) + EXP( -0.5_wp * dn ) ex2 = EXP( dn ) - EXP( -dn ) ex3 = EXP( -dn ) * ( 1.0_wp - dn ) - 0.5_wp * EXP( 0.5_wp * dn ) & - 0.5_wp * EXP( -0.5_wp * dn ) ex4 = EXP( dn ) + EXP( -dn ) ex5 = dn * sterm + ex1 / ex2 ex6 = sterm + ( ex3 * ex2 - ex4 * ex1 ) / ( ex2 * ex2 ) dnneu = dn - ex5 / ex6 dn = dnneu ENDDO IF ( sterm < 0.5_wp ) dn = MAX( 2.95E-2_wp, dn ) IF ( sterm > 0.5_wp ) dn = MIN( -2.95E-2_wp, dn ) ex1 = EXP( -dn ) ex2 = EXP( dn ) - ex1 aex(i) = -ex1 / ex2 bex(i) = 1.0_wp / ex2 dex(i) = dn eex(i) = EXP( dex(i) * 0.5_wp ) sterm = sterm + delt ENDDO ENDIF END SUBROUTINE init_advec