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-   -   Numerical oscillations in LES due to mesh refinement (http://www.cfd-online.com/Forums/openfoam/89491-numerical-oscillations-les-due-mesh-refinement.html)

Soder June 14, 2011 11:10

Numerical oscillations in LES due to mesh refinement
 
Hi all,

I am doing LES simulation of the flow past inlet valves in engines.
And it seems like I get some kind of numerical oscillation at regions where the mesh has been refined.
I have tried both rhoPisoFoam and rhoPimpleFoam the problem is more apparent in rhoPimpleFoam (oscillations in both velocity and pressure) then in rhoPisoFoam (only oscillations in the near wall pressure)

I have tried different schemes and number of correctors with no significant improvement.

Does anyone have an idea what parameters I could check. The mesh is ok according to checkMesh aswell as for the software used to generate it (Fire)

I have attached som figures showing the oscillations aswell as the mesh.

The one showing velocity is rhoPimpleFoam

Best regards
Martin
http://img716.imageshack.us/img716/5426/pisofine.jpg
Pressure fluctation at surface, rhoPisoFoam
http://img199.imageshack.us/img199/60/pimpleuvel.jpghttp://img88.imageshack.us/img88/9632/pimpleuvelgeo.jpg
Velocity fluctuations in rhoPimpleFoam


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