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Old   November 8, 2011, 15:55
Default [LaunderGibsonRSTM-channel]
  #1
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Join Date: Mar 2011
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Dear Foamers,

I'm trying to simulate a channel with the LaunderGibsonRSTM model. I would like to resolve the walls without using wall functions, my first y+ is therefore 0.63.

Unfortunately, my simulation blows up after a few time steps... I tried the solution provided by Sven in an other post regarding running the simulation with LaunderSharmaKE model and then use the RSTM... This is not working for me.

Relevant dictionaries of my 0 directory, fvSchemes, fvSolution are provided below.

initialisation epsilon:

Code:
/*--------------------------------*- 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       volScalarField;
    location    "0";
    object      epsilon;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -3 0 0 0 0];

internalField   uniform 4.5e-07;

boundaryField
{
    bottomWall
      {
        //      type epsilonWallFunction;
        //      value   uniform 1e-8;
                type            fixedValue;
                value           uniform 1e-16;  //This is not 0!!!
      }
    topWall
      {
        //      type epsilonWallFunction;
        //      value   uniform 1e-8;
                type            fixedValue;
                value           uniform 1e-16;  //This is not 0!!!
      }
    sides1
      {
        type            cyclic;
      }
    sides2
      {
        type            cyclic;
      }
    inout1
      {
        type            cyclic;
      }
    inout2
      {
        type            cyclic;
      }
}


// ************************************************************************* //
k:

Code:
/*--------------------------------*- 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       volScalarField;
    location    "0";
    object      k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 6.75e-05;

boundaryField
{
    bottomWall
      {
        type            fixedValue;                         //zeroGradient;
        value           uniform 1e-14;
      }
    topWall
      {
        type            fixedValue;
        value           uniform 1e-14;
      }
    sides1
      {
        type            cyclic;//empty;
      }
    sides2
      {
        type            cyclic;//empty;
      }
    inout1
      {
        type            cyclic;
      }
    inout2
      {
        type            cyclic;
      }
}


// ************************************************************************* //
R:
Code:
/*--------------------------------*- 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       volSymmTensorField;
    object      R;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform (0 0 0 0 0 0);

boundaryField
{
    bottomWall
    {
      //        type            kqRWallFunction;
              type            fixedValue;
        value           uniform ( 0 0 0 0 0 0 );
    }

    topWall
    {
              type            fixedValue;
              //        type            kqRWallFunction;
        value           uniform ( 0 0 0 0 0 0 );
    }
    sides1
      {
        type            cyclic;//empty;
      }
    sides2
      {
        type            cyclic;//empty;
      }
    inout1
      {
        type            cyclic;
      }
    inout2
      {
        type            cyclic;
      }
}

// ************************************************************************* //
fvSchemes:

Code:
/*--------------------------------*- 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    "system";
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         Euler;
}

gradSchemes
{
    default         Gauss linear;
    grad(p)         Gauss linear;
    grad(U)         Gauss linear;
}

divSchemes
{
    default              none;
    div(phi,U)           Gauss upwind;//Gauss limitedLinear 1.0;
    div(phi,k)           Gauss upwind;//Gauss limitedLinear 1;
    div(phi,epsilon)     Gauss upwind;//Gauss limitedLinear 1;
    div(phi,R)          Gauss upwind;//Gauss linear;
    div(R)              Gauss linear;
    div((nuEff*dev(grad(U).T()))) Gauss linear;
}

laplacianSchemes
{
    default         none;
    laplacian(nuEff,U) Gauss linear limited 0.333; //Gauss linear corrected;
    laplacian((1|A(U)),p) Gauss linear limited 0.333; //Gauss upwind corrected;
    laplacian(DkEff,k) Gauss linear limited 0.333; //Gauss upwind corrected;
    laplacian(DepsilonEff,epsilon) Gauss linear limited 0.333; //Gauss upwind corrected;
    laplacian(DREff,R) Gauss linear limited 0.333; //Gauss upwind corrected;
    //laplacian(DnuTildaEff,nuTilda) Gauss linear limited 0.333; //Gauss upwind corrected;
    //laplacian(nuEff,U) Gauss linear corrected;
    // laplacian((1|A(U)),p) Gauss linear corrected;
    //laplacian(DkEff,k) Gauss linear corrected;
    //laplacian(DepsilonEff,epsilon) Gauss linear corrected;
    //laplacian(DREff,R) Gauss linear corrected;

}

interpolationSchemes
{
    default         linear;
    interpolate(U)  linear;
}

snGradSchemes
{
 default         corrected;
}

fluxRequired
{
    default         no;
    p               ;
}


// ************************************************************************* //
fvSolution:

Code:
/*--------------------------------*- 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    "system";
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p
    {
        solver          PCG;
        preconditioner  DIC;
        tolerance       1e-06;
        relTol          0.1;
    }

    pFinal
    {
       solver          PCG;
       preconditioner  DIC;
       tolerance       1e-09;
       relTol          0;
    }

    U
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-07;
        relTol          0;
    }

    R
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-07;
        relTol          0;
    }

    epsilon
     {
       solver          PBiCG;
       preconditioner  DILU;
       tolerance       1e-07;
       relTol          0;
    }
}

PISO
{
    nCorrectors     2;
    nNonOrthogonalCorrectors 0;
    pRefCell        0;
    pRefValue       0;
}
//relaxationFactors
//{
// p 0.2;
// U 0.7;
// k 0.5;
// epsilon 0.1;
// R 0.5;
  //  nuTilda 0.3;
//}

// ************************************************************************* //
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Old   November 9, 2011, 09:04
Default
  #2
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issue solved. There exists no low Re formulation of the LaunderGibsonRSTM. Therefore wall functions have to be applied...
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