[Gearb0x]

Hello,

I'd like to know if the kOmegaSST in openfoam 1.6 is a low-re Models or not? because in fluent, if I understand well, it is.

Also, if that's the case, how to set it up?
Cause in the tutorials incompressible/simpleFoam/motorbike

in the "constant" directory of this case I have :
RASproperties

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.6                                   |
|   \\  /    A nd           | Web:      http://www.OpenFOAM.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      RASProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

RASModel            kOmegaSST;

turbulence          on;

printCoeffs         on;


// ************************************************************************* //

and
turbulenceproperties

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.6                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      turbulenceProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

turbulenceModel SpalartAllmaras;

turbulence      on;

laminarCoeffs
{
}

kEpsilonCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
}

RNGkEpsilonCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.0845;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.42;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.68;
    alphak          alphaK [ 0 0 0 0 0 0 0 ] 1.39;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 1.39;
    eta0            eta0 [ 0 0 0 0 0 0 0 ] 4.38;
    beta            beta [ 0 0 0 0 0 0 0 ] 0.012;
}

NonlinearKEShihCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphak          alphak [ 0 0 0 0 0 0 0 ] 1;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76932;
    A1              A1 [ 0 0 0 0 0 0 0 ] 1.25;
    A2              A2 [ 0 0 0 0 0 0 0 ] 1000;
    Ctau1           Ctau1 [ 0 0 0 0 0 0 0 ] -4;
    Ctau2           Ctau2 [ 0 0 0 0 0 0 0 ] 13;
    Ctau3           Ctau3 [ 0 0 0 0 0 0 0 ] -2;
    alphaKsi        alphaKsi [ 0 0 0 0 0 0 0 ] 0.9;
}

LienCubicKECoeffs
{
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphak          alphak [ 0 0 0 0 0 0 0 ] 1;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
    A1              A1 [ 0 0 0 0 0 0 0 ] 1.25;
    A2              A2 [ 0 0 0 0 0 0 0 ] 1000;
    Ctau1           Ctau1 [ 0 0 0 0 0 0 0 ] -4;
    Ctau2           Ctau2 [ 0 0 0 0 0 0 0 ] 13;
    Ctau3           Ctau3 [ 0 0 0 0 0 0 0 ] -2;
    alphaKsi        alphaKsi [ 0 0 0 0 0 0 0 ] 0.9;
}

QZetaCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphaZeta       alphaZeta [ 0 0 0 0 0 0 0 ] 0.76923;
    anisotropic     no;
}

LaunderSharmaKECoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
}

LamBremhorstKECoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
}

LienCubicKELowReCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphak          alphak [ 0 0 0 0 0 0 0 ] 1;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
    A1              A1 [ 0 0 0 0 0 0 0 ] 1.25;
    A2              A2 [ 0 0 0 0 0 0 0 ] 1000;
    Ctau1           Ctau1 [ 0 0 0 0 0 0 0 ] -4;
    Ctau2           Ctau2 [ 0 0 0 0 0 0 0 ] 13;
    Ctau3           Ctau3 [ 0 0 0 0 0 0 0 ] -2;
    alphaKsi        alphaKsi [ 0 0 0 0 0 0 0 ] 0.9;
    Am              Am [ 0 0 0 0 0 0 0 ] 0.016;
    Aepsilon        Aepsilon [ 0 0 0 0 0 0 0 ] 0.263;
    Amu             Amu [ 0 0 0 0 0 0 0 ] 0.00222;
}

LienLeschzinerLowReCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    alphak          alphak [ 0 0 0 0 0 0 0 ] 1;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
    Am              Am [ 0 0 0 0 0 0 0 ] 0.016;
    Aepsilon        Aepsilon [ 0 0 0 0 0 0 0 ] 0.263;
    Amu             Amu [ 0 0 0 0 0 0 0 ] 0.00222;
}

LRRCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    Clrr1           Clrr1 [ 0 0 0 0 0 0 0 ] 1.8;
    Clrr2           Clrr2 [ 0 0 0 0 0 0 0 ] 0.6;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    Cs              Cs [ 0 0 0 0 0 0 0 ] 0.25;
    Ceps            Ceps [ 0 0 0 0 0 0 0 ] 0.15;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
}

LaunderGibsonRSTMCoeffs
{
    Cmu             Cmu [ 0 0 0 0 0 0 0 ] 0.09;
    Clg1            Clg1 [ 0 0 0 0 0 0 0 ] 1.8;
    Clg2            Clg2 [ 0 0 0 0 0 0 0 ] 0.6;
    C1              C1 [ 0 0 0 0 0 0 0 ] 1.44;
    C2              C2 [ 0 0 0 0 0 0 0 ] 1.92;
    C1Ref           C1Ref [ 0 0 0 0 0 0 0 ] 0.5;
    C2Ref           C2Ref [ 0 0 0 0 0 0 0 ] 0.3;
    Cs              Cs [ 0 0 0 0 0 0 0 ] 0.25;
    Ceps            Ceps [ 0 0 0 0 0 0 0 ] 0.15;
    alphaEps        alphaEps [ 0 0 0 0 0 0 0 ] 0.76923;
    alphaR          alphaR [ 0 0 0 0 0 0 0 ] 1.22;
}

SpalartAllmarasCoeffs
{
    alphaNut        alphaNut [ 0 0 0 0 0 0 0 ] 1.5;
    Cb1             Cb1 [ 0 0 0 0 0 0 0 ] 0.1355;
    Cb2             Cb2 [ 0 0 0 0 0 0 0 ] 0.622;
    Cw2             Cw2 [ 0 0 0 0 0 0 0 ] 0.3;
    Cw3             Cw3 [ 0 0 0 0 0 0 0 ] 2;
    Cv1             Cv1 [ 0 0 0 0 0 0 0 ] 7.1;
    Cv2             Cv2 [ 0 0 0 0 0 0 0 ] 5;
}

wallFunctionCoeffs
{
    kappa           kappa [ 0 0 0 0 0 0 0 ] 0.4187;
    E               E [ 0 0 0 0 0 0 0 ] 9;
}


// ************************************************************************* //

I don't understand why in RAS it's "kOmegaSST" and in turbulence "spalartAllmaras"
Shouldn't it be the same? Does the 2 files are needed?

Thanks for your help

[SD@TUB]

Hello Gearb0x,

the kOmegaSST turbulence model works with wall functions solely. So it is a high-Re-model!
In my state of knowledge there exist a low-Re-model. You will find some discussions within this forum.
According to the tutorial "incompressible/simpleFoam/motorbike" i guess that RASproperties is dominant and the solver initialize the associated coeffs from the turbuenceProperties dict.

/Stefan

[Gearb0x]

Thanks for your help

So the model is not useful in my case