Changeset 3890

Timestamp:

Apr 12, 2019 3:59:20 PM (6 years ago)

Author:

suehring

Message:

Check if grid coarsening is possible on subdomain, in order to avoid that multigrid approach effectively reduces to a Gauss-Seidel scheme.

File:

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

palm/trunk/SOURCE/init_pegrid.f90

@@ -25 +25 @@
 ! -----------------
 ! $Id$
+! Check if grid coarsening is possible on subdomain, in order to avoid that 
+! multigrid approach effectively reduces to a Gauss-Seidel scheme.
+! 
+! 3885 2019-04-11 11:29:34Z kanani
 ! Changes related to global restructuring of location messages and introduction 
 ! of additional debug messages
@@ -947 +951 @@
 
        maximum_grid_level = MIN( mg_levels_x, mg_levels_y, mg_levels_z )
+!       
+!--    Check if subdomain sizes prevents any coarsening. 
+!--    This case, the maximum number of grid levels is 1, i.e. effectively 
+!--    a Gauss-Seidel scheme is applied rather than a multigrid approach.
+       IF ( maximum_grid_level == 1 )  THEN
+          message_string = 'grid coarsening on subdomain level cannot be ' //  &
+                           'performed'
+          CALL message( 'poismg', 'PA0236', 1, 2, 0, 6, 0 )
+       ENDIF
 
 !
@@ -1085 +1098 @@
           nyn_l = nyn_l / 2 
           nzt_l = nzt_l / 2 
-
+          
        ENDDO