[guserik]

Hello

I got problem with time step continuity when try to run rhoPimpleFoam, i have 2 regions with 8 bar in pressure differnce. When i start my simulation i got really high error directly in the second iteration step. I have tried to change alot of parameters in my fvSolution and fvSchemes without any sucess.

time step continuity errors : sum local = 0.463969, global = -0.463969, cumulative = -5.10366
rho max/min : 6.5 1.05679

/*--------------------------------*- 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         Euler;
}
gradSchemes
{
    default         Gauss linear;
}
divSchemes
{
    default         none;
    div(phi,U)      Gauss upwind limited 1;
    div(phi,h)      Gauss upwind;
    div(phi,k)      Gauss upwind;
    div(phi,epsilon) Gauss upwind;
    div((muEff*dev2(T(grad(U))))) Gauss linear;
    div(phi,K)      Gauss linear;
}
laplacianSchemes
{
    default         none;
    laplacian(muEff,U) Gauss linear corrected;
    laplacian(Dp,p) Gauss linear corrected;
    laplacian(alphaEff,h) Gauss linear corrected;
    laplacian(DkEff,k) Gauss linear corrected;
    laplacian(DepsilonEff,epsilon) Gauss linear corrected;
}
interpolationSchemes
{
    default         linear;
    interpolate(U)  linear;
}
snGradSchemes
{
    default         corrected;
}
fluxRequired
{
    default         yes;
    p               ;
}

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

/*--------------------------------*- 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
{
    rho
    {
        solver          PCG;
        preconditioner  DIC;
        tolerance       1e-10;
        relTol          0;
    }
    rhoFinal
    {
        $rho;
        tolerance       1e-10;
        relTol          0;
    }
    U
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps         2;
        tolerance       1e-10;
        relTol          0;
    }
    UFinal
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-10;
        relTol          0.01;
    }
    p
    {
        solver          GAMG;
        tolerance       1e-11;
        relTol          0;
        smoother        GaussSeidel;
        nPreSweeps      1;
        nPostSweeps     1;
        cacheAgglomeration true;
        nCellsInCoarsestLevel 100;
        agglomerator    faceAreaPair;
        mergeLevels     1;
  maxIter 1500;
    }
    pFinal
    {
        $p;
        relTol          0;
    }
 
 
    h
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-10;
        relTol          0;
    }
    hFinal
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-10;
        relTol          0;
    }
    "(k|epsilon)"
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-5;
        relTol          0.1;
    }
    "(k|epsilon)Final"
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-10;
        relTol          0.1;
    }
}
PIMPLE
{
    nOuterCorrectors 3;
    nCorrectors     3;
    nNonOrthogonalCorrectors 1;
    momentumPredictor yes;
    rhoMin          rhoMin [ 1 -3 0 0 0 ] 0.5;
    rhoMax          rhoMax [ 1 -3 0 0 0 ] 6.5;
}
relaxationFactors
{
    default         0;   //Other tries : 
    p               0.01; //  0.3 0.2 0.3
    U               0.01; //  0.5 0.2 0.5
    nuTilda         0.7; //  0.6 0.4 0.6
    h               0.01; //  0.6 0.4 0.3
    rho             0.05; // 0.05 0.05 0.025
    hFinal          0.01; //  0.6 0.6 0.3
    "(U|nuTilda)Final"  0.07; // 0.6  0.4 0.6
}

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

[adambarfi]

see these links:

http://openfoamwiki.net/index.php/HowTo_debugging

http://www.cfd-online.com/Forums/ope...rintstack.html

perhaps it's because of your mesh, your BCs and ....
what is the error exactly?