[vcvedant]

Hello,

I am simulating flow around vane cascade. I have good mesh quality with checkMesh reporting OK for all checks and the maximum non-orthogonality at 41.
I was able to get converged solution with first order schemes (bounded Gauss upwind) but when i switched to higher order schemes, my solution diverged with 'Nan'.
Solver: simpleFoam
RASModel: LaunderSharmaKE (or kOmegaSST)

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.2                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         steadyState;
}

gradSchemes
{
    default         Gauss linear;
    grad(U)         leastSquares;
    grad(T)        leastSquares;
}    

divSchemes
{
    default                 none;
    div(phi,U)                 bounded Gauss linearUpwind grad(U);    
    div(phi,k)                bounded Gauss linearUpwind default;
    div(phi,epsilon)        bounded Gauss upwind;
    div(phi,R)            bounded Gauss linearUpwind default;
    div(phi,nuTilda)         bounded Gauss linearUpwind default;
    div((nuEff*dev(T(grad(U))))) Gauss linear;
    div(phi,T)            bounded Gauss linearUpwind grad(T);    
}

laplacianSchemes
{
    default                    Gauss linear corrected;
    laplacian(1,Phi)            Gauss linear corrected;// limited 0.5;
    laplacian(nuEff,U)             Gauss linear corrected;// limited 0.5;
    laplacian((1|A(U)),p)         Gauss linear corrected;// limited 0.5;
    laplacian(DkEff,k)             Gauss linear corrected;// limited 0.5;
    laplacian(DepsilonEff,epsilon)     Gauss linear corrected;// limited 0.5;
    laplacian(DREff,R)             Gauss linear corrected;// limited 0.5;
    laplacian(DnuTildaEff,nuTilda)     Gauss linear corrected;// limited 0.5;
    laplacian(kappaEff,T)        Gauss linear corrected;// limited 0.5;
}

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

snGradSchemes
{
    default         corrected;
}

fluxRequired
{
    default         no;
    p               ;
    Phi;
}

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

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.2                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{   
    Phi
    {

    solver        GAMG;
    smoother    DIC;//GaussSeidel;
    cacheAgglomeration    on;
    agglomerator    faceAreaPair;
    nCellsInCoarsestLevel    10;
    mergeLevels    1;
    tolerance    1e-6;
    relTol        0.01;
    }    


    p
    {
    solver        PCG;
    preconditioner    DIC;
    tolerance    1e-12;
    relTol        0.0001;
    //maxIter        200;
/*    
        solver          GAMG;
        tolerance       1e-08;
        relTol          0.001;
    minIter        5;    //added later
    maxIter        200;    //added later
        smoother        GaussSeidel;    // DIC; //DICGaussSeidel; //FDIC;
        nPreSweeps      1;
        nPostSweeps     3;
    nFinestSweeps    3;
        cacheAgglomeration true;
        nCellsInCoarsestLevel 100;
        agglomerator    faceAreaPair;
        mergeLevels     1;
*/    
    }
/*    pFinal
    {
    $p;
    relTol        0;
    }
*/

    "(U|T|k|epsilon)"
    {

        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-08;
        relTol          0.1;
/*
    solver        smoothSolver;
    smoother    GaussSeidel;
    tolerance    1e-3;
    relTol        0;
*/


    }
    "(R|nuTilda)"
    {
    
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-08;
        relTol          0.1;
/*
    solver        smoothSolver;
    smoother    GaussSeidel;
    tolerance    1e-3;
    relTol        0;
  */  }
}

SIMPLE
{
    nNonOrthogonalCorrectors 0;
   
    residualControl
    {
        p    1e-8;
        U    1e-8;
        k    1e-8;
        epsilon    1e-8;
                T    1e-8;
        
    }
   
}

potentialFlow
{
    nNonOrthogonalCorrectors    10;
}

relaxationFactors
{
    fields
    {
    p               0.1;
    }
    equations
    {
         default     0.3;
    U        0.5;
    k        0.5;
    epsilon        0.5;
    R        0.4;
    T        0.6;
    nuTilda        0.4;
    }
}


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

It would be really great if someone has suggestions for me.

Thanks

[chpjz0391]

Hi,

Could you please post your log file?

[vcvedant]

Hello Ping,

I had tried several fvSchemes options for divergence before settling on the ones that I mentioned. My log files are for kwSST model where omega is bounded Gauss upwind and all other are same.

Link to log files


Thanks