[volker]

Hi,

I experienced a problem when using the post-processing utility R to evaluate the Reynolds stress tensor based on a compressible simulation using a kEpsilon turbulence model. The Reynolds stress tensor is needed as initialization for a RSM simulation.
The problem I experienced is basically related to the compressible nature of my simulation and it seems that the R-utility is written exclusively for incompressible flows (makes use of transportProperties file).
I searched already the forum without success.
Does anybody have a suggestion how to resolve that issue?


I'm happy about any idea.


Greets, Volker

[SD@TUB]

Hello Volker,

reading in Doxygen --> base class for incompressible turbulence models, i guess that R just work for incompressible turbulent calcualtions so far.

I tried some sampling with your mentioned tool and i'm a little confused, 'cause i get six columns for the reynolds stress tensor in my output file!
Could you/someone explain me the columns? In Doxygen i can't find the source of the utility R!
For future development of post-processing tools it would be useful to include an obvious header to the produced output files.


Regards,
/Stefan

[chegdan]

Originally Posted by SD@TUB

Hello Volker,

reading in Doxygen --> base class for incompressible turbulence models, i guess that R just work for incompressible turbulent calcualtions so far.

I tried some sampling with your mentioned tool and i'm a little confused, 'cause i get six columns for the reynolds stress tensor in my output file!
Could you/someone explain me the columns? In Doxygen i can't find the source of the utility R!
For future development of post-processing tools it would be useful to include an obvious header to the produced output files.


Regards,
/Stefan

I know this is old, but I thought I would answer anyway.

You only have 6 components because you have a symmetric tensor Rxx, Ryy, Rzz, Rxy, Rxz, Ryz. that means that Rxy=Ryx, Rxz=Rzx, and Ryz=Rzy.

[rajeshkunwar]

Hi Volker,

I am also facing the same problem while getting Reynolds stress. Did u solve this issue? If yes, please post the solution so that others can also get benefited.

Regards
Rajesh

[chegdan]

You can make a custom tool to calculate R for compressible cases. To create a compressible turbulence model you will need to read in:

    Info<< "Creating turbulence model\n" << endl;
    autoPtr<compressible::turbulenceModel> turbulence
    (
        compressible::turbulenceModel::New
        (
            rho,
            U,
            phi,
            thermo
        )
    );

So you will need a thermo object to pass to the constructor. Basically, you will have to look at a compressible solver (e.g. rhoPimpleFoam) and add things like a compressible phi, thermo from basiPsiThermo, etc. Most of these changes are in the createFields.H file in the R utility....but I suggest you make your own utility separately called something like "Rcompressible". Additioanlly, you will have to change some entries in the Make/Options file to let the compiler know where to search for these new "compressible" classes. Hope this helps.

[rajeshkunwar]

Thanks Mr. Daniel for your help.

I have created the utility for computing Reynolds stresses for compressible solver.

Regards
Rajesh