k-epsilon constants modification

[MaximeO]

Hello,

For a study about the flow and dispersion around a building, I would like to see the influence of the modifications of the k-epsilon (or k-epsilon linar production) model constants as shown in few articles that i found. The five constants are : , , , and .

However, only the first three seem to appear in the cs_turbulence_model.c or in the setup.log file obtained after a computation (cf. extract of one of my setup.log file below).

Code: Select all

  k-epsilon model with Linear Production (LP) correction constants:
    ce1:            1.44000e+00 (Cepsilon 1: production coef.)
    ce2:            1.92000e+00 (Cepsilon 2: dissipat.  coef.)
    cmu:            9.00000e-02 (Cmu constant)

I found "sigmak" and "sigmae" variables in src/base/clptrg.f90 and src/base/clptur.f90 which seem to correspond to the two other constants, but I don't know how and where are exactly declared the two sigma constants, and so if we can modify them by a user fonction.

I'm working on code_saturne v8.0.

Best regards,

Maxime

[louis.simvia]

Hello Maxime,

Have you checked this page of the documentation ?
https://www.code-saturne.org/documentat ... sttur.html

Also be careful that code_saturne has two k-epsilon model (linearized or not). I believe the constants sigma_k and sigma_epsilon appears in both but you should probably check the documentation if you want to make some more specific modifications to the constants.

[MaximeO]

Hello Louis,

Thank you for your response.

I have checked this document, which if I'm not mistaken refers to the cs_turbulence.c file I was talking about, but it doesn't mention the sigma_k and sigma_e constants.
I think the two sigma constants should indeed appear in both standard and linearized k-epsilon model, but as I said I didn't find any information about these two. And as they don't appear in the setup.log file, I am wandering if and how we can use them.

Best regards,

Maxime

[StandardRANSUser001]

Not an expert on k-epsilon, however, aren't all model coefficients defined in cs_turbulence_model.c/cpp? They may be shared across several models perhaps?
https://github.com/code-saturne/code_sa ... _model.cpp

Best regards,
Sean Hanrahan