[cig-commits] commit: Reduce the upwind diffusivity even more in case of distorted elements.

[Mercurial]

changeset:   837:48bc6ad34fcd
tag:         tip
user:        Walter Landry <wlandry at caltech.edu>
date:        Mon Jul 09 15:32:40 2012 -0700
files:       SLE/ProvidedSystems/AdvectionDiffusion/src/UpwindParameter.cxx
description:
Reduce the upwind diffusivity even more in case of distorted elements.


diff -r 8cd0adf15d97 -r 48bc6ad34fcd SLE/ProvidedSystems/AdvectionDiffusion/src/UpwindParameter.cxx
--- a/SLE/ProvidedSystems/AdvectionDiffusion/src/UpwindParameter.cxx	Mon Jul 02 17:03:03 2012 -0700
+++ b/SLE/ProvidedSystems/AdvectionDiffusion/src/UpwindParameter.cxx	Mon Jul 09 15:32:40 2012 -0700
@@ -153,9 +153,12 @@ double AdvDiffResidualForceTerm_UpwindDi
     }
   upwindDiffusivity*=ISQRT15;         /* See Eq. 3.3.11 */
 
-  upwindDiffusivity/=2; /* This factor is because we are using Q2
+  upwindDiffusivity/=16; /* This factor is because we are using Q2
                            instead of Q1 elements, so the spacing
-                           needs to be adjusted. */
+                           needs to be adjusted.  That gives a factor
+                           of 2, but we make it a factor of 16 to
+                           ensure stability even when the mesh is
+                           distorted. */
 	
   return upwindDiffusivity;
 }