From 142776ae2f81372d19b05e897cf5714e1da42069 Mon Sep 17 00:00:00 2001
From: Henry <Henry>
Date: Sat, 10 Jan 2015 11:27:14 +0000
Subject: [PATCH] advectionDiffusionPatchDistMethod: Added more description
including specification of relaxation
---
.../advectionDiffusionPatchDistMethod.H | 35 +++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/src/finiteVolume/fvMesh/wallDist/patchDistMethods/advectionDiffusion/advectionDiffusionPatchDistMethod.H b/src/finiteVolume/fvMesh/wallDist/patchDistMethods/advectionDiffusion/advectionDiffusionPatchDistMethod.H
index 22a8cd07a2a..be8a2489e64 100644
--- a/src/finiteVolume/fvMesh/wallDist/patchDistMethods/advectionDiffusion/advectionDiffusionPatchDistMethod.H
+++ b/src/finiteVolume/fvMesh/wallDist/patchDistMethods/advectionDiffusion/advectionDiffusionPatchDistMethod.H
@@ -29,6 +29,17 @@ Description
boundary by solving the Eikonal equation in advection form with diffusion
smoothing.
+ If the diffusion coefficient is set to 0 this method is exact in principle
+ but the numerical schemes used are not rendering the scheme approximate, but
+ more accurate than the Poisson method. Also many models relying on the
+ distance to the wall benefit from this field being smooth and monotonic so
+ the addition of diffusion smoothing improves both the convergence and
+ stability of the solution of the Eikonal equation and the behavior of the
+ models using the distance field generated. However, it is not clear what
+ the optimum value for the diffusion coefficient epsilon should be; a
+ default value of 0.1 is provided but higher values may be preferable under
+ some circumstances.
+
Convergence is accelerated by first generating an approximate solution
using one of the simpler methods, e.g. Poisson. The method used for
this prediction step is specified in the 'advectionDiffusionCoeffs'
@@ -90,6 +101,18 @@ Description
relTol 0;
}
+ relaxationFactors
+ {
+ equations
+ {
+ .
+ .
+ yWall 1;
+ .
+ .
+ }
+ }
+
or for more complex cases:
yPsi
@@ -115,6 +138,18 @@ Description
tolerance 1e-4;
relTol 0;
}
+
+ relaxationFactors
+ {
+ equations
+ {
+ .
+ .
+ yWall 0.7;
+ .
+ .
+ }
+ }
\endverbatim
SeeAlso
--
GitLab