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April 7, 2016, 15:42 |
Modifying Turbulence Model Coefficients
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#1 |
New Member
Join Date: Apr 2012
Posts: 9
Rep Power: 14 |
I'm working with the v2f RAS model. Ultimately, I'd like to be able to modify the model's coefficients without having to recompile.
The two files, v2f.C and v2f.H, found in the directory, /src/turbulenceModels/incompressible/RAS/v2f/, seem to contain everything I need to make the changes. v2f.C contains a section called "Constructors" and looks like this Code:
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * // v2f::v2f ( const volVectorField& U, const surfaceScalarField& phi, transportModel& transport, const word& turbulenceModelName, const word& modelName ) : RASModel(modelName, U, phi, transport, turbulenceModelName), Cmu_ ( dimensioned<scalar>::lookupOrAddToDict ( "Cmu", coeffDict_, 0.22 ) ), CmuKEps_ ( dimensioned<scalar>::lookupOrAddToDict ( "CmuKEps", coeffDict_, 0.09 ) ), ... 7.2.1 Model coefficients The coefficients for the RAS turbulence models are given default values in their respective source code. If the user wishes to override these default values, then they can do so by adding a sub-dictionary entry to the RAS sub-dictionary file, whose keyword name is that of the model with Coeffs appended, e.g. kEpsilonCoeffs for the kEpsilon model. If the printCoeffs switch is on in the RAS sub-dictionary, an example of the relevant …Coeffs dictionary is printed to standard output when the model is created at the beginning of a run. The user can simply copy this into the RAS sub-dictionary file and edit the entries as required. And the v2f.H file contains the following in the header: Code:
\verbatim v2fCoeffs { Cmu 0.22; CmuKEps 0.09; C1 1.4; C2 0.3; CL 0.23; Ceta 70; Ceps2 1.9; sigmaEps 1.3; sigmaK 1; } \endverbatim So, I guess my real question is: what is the easiest way to modify these coefficients? And, does this require that I compile the RAS directory (using the Allwmake found in the /src/turbulenceModels/incompressible/ directory, parallel to the /RAS/ directory)? Thanks! |
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