Changeset 3120 for palm/trunk/SOURCE/timestep.f90

Timestamp:

Jul 11, 2018 6:30:57 PM (6 years ago)

Author:

gronemeier

Message:

implementation of dynamic sgs model

File:

• palm/trunk/SOURCE/timestep.f90 (modified) (3 diffs)

palm/trunk/SOURCE/timestep.f90

@@ -25 +25 @@
 ! -----------------
 ! $Id$
+! Put ABS( km ) in computation of time step according to the diffusion criterion
+! 
+! 3084 2018-06-19 15:30:55Z gronemeier
 ! limit increase of dt_3d only in case of RANS mode
 ! 
@@ -302 +305 @@
 !
 !--    Compute time step according to the diffusion criterion.
-!--    First calculate minimum grid spacing which only depends on index k
+!--    First calculate minimum grid spacing which only depends on index k.
+!--    When using the dynamic subgrid model, negative km are possible.
        dt_diff_l = 999999.0_wp
 
@@ -315 +319 @@
              DO  k = nzb+1, nzt
                 dt_diff_l = MIN( dt_diff_l, dxyz2_min(k) /                     &
-                                    ( MAX( kh(k,j,i), km(k,j,i) ) + 1E-20_wp ) )
+                                    ( MAX( kh(k,j,i), ABS( km(k,j,i) ) )       &
+                                      + 1E-20_wp ) )
              ENDDO
           ENDDO