|November 9, 2012, 17:58||
continuity, k and epsilon divergence & skewness problem
Join Date: Sep 2012
Posts: 76Rep Power: 5
Here is the problem,
I am trying to simulate (steady state) air flow in a room(with multiple rectangular blocks in it). The simulation is getting blown after certain iterations.Continuity , k and epsilon are diverging. I am using k- epsilon turbulence model. I have calculated the k and epsilon values and have given them in inlet boundary condition (0.005, 15). I tried to tweak the URFs but it was no use, the solution is still getting blown. Then I thought, may be it is due to the mesh. I checked the mesh quality and found out that the skewness factor to be greater than 0.98 (0.99998) and aspect ratio greater than 500. Then I tried to refine the mesh. But the problem was, even though after refinement there was no improvement in skewness. I have used patch conforming method with curvature option. I tried to use proximity and curvature option but the meshing is getting stuck.
Kindly suggest me something.
some general questions:
1.How to improve skewness and aspect ratio?
2.Is it fine to have aspect ratio greater than 100 ? ( I don't think so but I just want to conform it.)
3.I know one wont get proper solution if there is a bad mesh ( not deltax size but quality), but do the solution diverge if we have a bad mesh ( again not refinement but quality) ?
4.Is there any way to control the divergence apart from the URFs if it is not a problem in mesh?
|Thread||Thread Starter||Forum||Replies||Last Post|
|SimpleFoam k and epsilon bounded||nedved||OpenFOAM Running, Solving & CFD||13||November 4, 2013 15:13|
|How to write k and epsilon before the abnormal end||xiuying||OpenFOAM Running, Solving & CFD||8||August 27, 2013 15:33|
|Orifice Plate with a fully developed flow - Problems with convergence||jonmec||OpenFOAM Running, Solving & CFD||3||July 28, 2011 05:24|
|SimpleFoam k and epsilon bounded||nedved||OpenFOAM Running, Solving & CFD||1||November 25, 2008 21:21|
|Severe nonorthogonality and severe skewness problem||qtian||OpenFOAM Running, Solving & CFD||2||January 22, 2008 19:47|