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-   -   difference between incompressible k-epsilon model and compressible k-epsilon model (https://www.cfd-online.com/Forums/openfoam-solving/137443-difference-between-incompressible-k-epsilon-model-compressible-k-epsilon-model.html)

yhy20081016 June 16, 2014 23:03

difference between incompressible k-epsilon model and compressible k-epsilon model
 
Hi, does anybody know the difference between incompressible k-epsilon model and compressible k-epsilon model in OpenFOAM? I found that the compressible model has more model constants. For example, the model constants for the incompressible RNG k-epsilon model are
RNGkEpsilonCoeffs
{
Cmu 0.0845;
C1 1.42;
C2 1.68;
sigmak 0.71942;
sigmaEps 0.71942;
eta0 4.38;
beta 0.012;
}
howerer, the model constants for the compressible RNG k-epsilon model are
RNGkEpsilonCoeffs
{
Cmu 0.0845;
C1 1.42;
C2 1.68;
C3 -0.33; // only for compressible
Prt 1.0; // only for compressible
sigmak 0.71942;
sigmaEps 0.71942;
eta0 4.38;
beta 0.012;
}
By the way, where can I find some references about the details of turbulence models in OpenFOAM?

Linse December 4, 2014 09:15

Information concerning Turbulence Models
 
Dear Yehanyu,

Although probably you found some answers already, for the matter of completeness:
Concerning turbulence models within OpenFOAM I strongly suggest to read the original publications. It seems OpenFOAM is dearly missing the documentation about these.
Moreover I suggest to check if the models are correctly implemented. In particular I am reviewing the implementation of the RNG-k-Epsilon model, as it might be useful for one of my simulations. It might be implemented correctly, but I am not sure yet.

For RNG-k-Epsilon, the original paper seems to be
Yakhot, Orszag, Thangam et al.: Development of turbulence models for shear flows by a double expansion technique; Physics of Fluids A, 4, 1510 (1992)

Cheers,
Bernhard

yhy20081016 December 6, 2014 01:25

Quote:

Originally Posted by Linse (Post 522483)
Dear Yehanyu,

Although probably you found some answers already, for the matter of completeness:
Concerning turbulence models within OpenFOAM I strongly suggest to read the original publications. It seems OpenFOAM is dearly missing the documentation about these.
Moreover I suggest to check if the models are correctly implemented. In particular I am reviewing the implementation of the RNG-k-Epsilon model, as it might be useful for one of my simulations. It might be implemented correctly, but I am not sure yet.

For RNG-k-Epsilon, the original paper seems to be
Yakhot, Orszag, Thangam et al.: Development of turbulence models for shear flows by a double expansion technique; Physics of Fluids A, 4, 1510 (1992)

Cheers,
Bernhard

Thank you very much.

JasonWang3 January 19, 2016 07:49

Hi

Do you find any relative papers about the compressible k-epsilon model? I can not find a clue where the C3 term come from.


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