[pawlo]

Hello everybody!

I am new to OpenFOAM (v2.3) and trying to do a transient turbulent simulation with kEpsilon RASModel with the PIMPLE solver. I have copied all settings from tutorial examples and changed the geometry to my problem-geometry.

Because of some convergence problems i tried to change some entries in the fvSchemes file.

In the fvSchemes file there are the following divSchemes:

divSchemes
{
    default         none;
    div(phi,U)      bounded Gauss linearUpwind grad(U);
    div(phi,k)      bounded Gauss upwind;
    div(phi,epsilon) bounded Gauss upwind;
    div((nuEff*dev(T(grad(U))))) Gauss linear;
}

After playing around for some time i recognized that if i remove the entries for "k" and "epsilon", so that divSchemes looks like this:

divSchemes
{
    default         none;
    div(phi,U)      bounded Gauss linearUpwind grad(U);
    div((nuEff*dev(T(grad(U))))) Gauss linear;
}

OpenFOAM still starts the simulation without complaining about the missing entries. Whereas when i delete "div((nuEff*dev(T(grad(U))))) Gauss linear;" the simulation does not start because OpenFOAM complains that this entry is missing.

Does somebody know why removing the entries for "k" and "epsilon" does not make any difference? Is there a default value in the standard "kEpsilon" model?

Regarding the turbulence model:

I have all files, like RASProperties, turbulenceProperties, and transportProperties defined. I you want to see them please tell me, but i think they are properly defined.

[Antimony]

Hi,

Maybe I am wrong, but how often do you ask your solver to solve for turbulence? Is it only at the end of the inner loops for the transient solver? If it is only at the end, then my guess is that you will get an error saying that div(phi,k) has not be defined etc.

You could give it a shot and see.

Cheers,
Antimony

[pawlo]

Thank you! Now OpenFOAM complains when the entries for k and epsilon are missing. The problem was that is was too impatient. The turbulence was only solved at the end of all pimple iterations and i was expecting OpenFOAM to complain right at the beginning of a time step.