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Numerical Problems with Non-Linear RAS models

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Old   February 9, 2010, 06:15
Default Numerical Problems with Non-Linear RAS models
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Markus Weinmann
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Hi all,

I am trying to simulate the flow in a channel with periodic hills using a nonlinear RAS model and simpleFoam (incompressible).
The mesh is of good quality and I am using upwind schemes for all quantities apart from the non-linear stress term:
div(nonlinearStress) Gauss linear;

My problem is that I get massive oscillations in almost all flow quantities, see attached pictures!

I am quite sure that the oscillations are caused by using: div(nonlinearStress) Gauss linear;
Therefore, I have tried to use a limited version (e.g. div(nonlinearStress) Gauss limitedLinear 1; ) but this does not work.

Does anyone know how a bounded version of Gauss linear can be used on div(nonlinearStress)?

Many Thanks
Markus
Attached Images
File Type: jpg nut.JPG (30.4 KB, 21 views)
File Type: jpg pressure.JPG (17.9 KB, 15 views)
File Type: jpg shearStress.JPG (28.4 KB, 18 views)
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