[miladrakhsha]

Hello everyone,
I am using OpenFOAM-1.6-ext at this time and using kOmegaSST turbulent model. Is there anyway I can use "bounded" scheme in OpenFOAM-1.6-ext??

Time = 1

DILUPBiCG:  Solving for Ux, Initial residual = 0.00154947, Final residual = 4.86454e-05, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.00151971, Final residual = 4.23945e-05, No Iterations 1
DILUPBiCG:  Solving for Uz, Initial residual = 1, Final residual = 0.01419, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.99997, Final residual = 0.000632842, No Iterations 10
time step continuity errors : sum local = 0.00157748, global = 1.86897e-10, cumulative = 1.86897e-10
DILUPBiCG:  Solving for omega, Initial residual = 0.00764356, Final residual = 3.68028e-05, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.000621706, Final residual = 7.47442e-05, No Iterations 1
bounding k, min: -0.0002366 max: 0.775536 average: 0.0108005

I searched a lot but I was not able to figure this out. My simulation terminates without any errors or warnings and I have absolutely no idea what else could be the reason!

[RodriguezFatz]

Try to use other gradient limiter and other gradient calculation method for k and omega. Such as cellLimited Gauss linear 1, faceMDLimited edgeCellsLeastSquares 1, ... There are a lot of possible combinations.
I know this needs a lot of trial and error, but in my experience this works.

[miladrakhsha]

Hi,
Thank you for the response, I am actually using upwind scheme for the k and omega which I believe should be stable enough because of being diffusive. Here is my fvScheme file

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default                     steadyState;
}

gradSchemes
{
    default                     Gauss linear;
}

divSchemes
{
    default                     Gauss upwind;

    div(phi,U)                  Gauss linearUpwind cellLimited Gauss linear 1;
    div(phi,k)                  Gauss upwind;
    div(phi,omega)              Gauss upwind;
    div(phi,nuTilda)              Gauss upwind;
    div((nuEff*dev(T(grad(U)))))     Gauss linear;
    div((nuEff*dev(grad(U).T())))       Gauss linear;
    div(R)                    Gauss linear;
    
}

laplacianSchemes
{
    default                     Gauss linear corrected;
   laplacian(nuEff,U)             Gauss linear limited 0.5;
   laplacian((1|A(U)),p)         Gauss linear limited 0.5;
   laplacian(DkEff,k)             Gauss linear uncorrected;
   laplacian(DepsilonEff,epsilon)     Gauss linear uncorrected;
   laplacian(DomegaEff,omega)         Gauss linear uncorrected;
   laplacian(DREff,R)             Gauss linear limited 0.5;
   laplacian(DnuTildaEff,nuTilda)     Gauss linear limited 0.5;
   //potentialFoam
    laplacian(1,p)              Gauss linear limited 0.5;

}

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

snGradSchemes
{
    default                     bounded;

}

fluxRequired
{
    default         no;
    p;
}

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

Can you suggest a stable descritization file?

I would appreciate it
Milad

[RodriguezFatz]

Hi,

1) What solver do you use?
2) What boundary conditions?
3) In my experience changing the convective scheme doesn't solve the k and omega bounding problem. Here, it was always the gradient+limiter.
4) How do the solver settings of fvSolution look like?

Edit: Just try

grad(k) faceLimited edgeCellsLeastSquares 1;
grad(omega) faceLimited edgeCellsLeastSquares 1;

[miladrakhsha]

I am experiencing with simpleIbFoam which is the modification of simpleFoam for Immersed body method, the boundary conditions are validated using simpleFoam solver. However, for the immersed body I have something like this for
U:

   VGIB
    {
        type immersedBoundaryWallFunction;
        patchType immersedBoundary;

        refValue uniform (0 0 0);
        refGradient  uniform (0 0 0);
        fixesValue yes;

    value uniform (0 0 0);

        setDeadCellValue   yes;
        deadCellValue      (0 0 0);
    }

p:

   VGIB
    {
        type immersedBoundary;
        refValue uniform 0;
        refGradient  uniform 0;
        fixesValue no;
    //value uniform 0;
        setDeadCellValue   yes;
        deadCellValue      0;

        value uniform 0;
    }

omega:

  VGIB
    {
        type immersedBoundaryWallFunction;
        patchType immersedBoundary;

        refValue uniform 1e-10;
        refGradient  uniform 0;
        fixesValue no;
    value    uniform 1;
        setDeadCellValue   yes;
        deadCellValue      1e-10;
    }

k:

    VGIB
    {
        type immersedBoundaryWallFunction;
        patchType immersedBoundary;

        refValue uniform 1e-8;
        refGradient  uniform 0;
        fixesValue no;
    value uniform 1e-10;
        setDeadCellValue   yes;
        deadCellValue      1e-8;
    }

It is worth mentioning that I have tried immersedBoundaryOmegaWallFunction but for some reason it does not work correctly. And finally this is my fvSolution file:

  p
     {
         solver          GAMG;
         tolerance       1e-06;
         relTol          0.001;
         minIter      1;
         smoother        GaussSeidel;
         cacheAgglomeration true;
         nCellsInCoarsestLevel 10;
         agglomerator    faceAreaPair;
         mergeLevels     1;
    maxIter        2000;
     }

U
    {
        solver           PBiCG;
        preconditioner   DILU;

        minIter          1;
        maxIter          1000;
        tolerance        1e-06;
        relTol           1e-001;
    }

    k
   {
           solver           PBiCG;
        preconditioner   DILU;

        minIter          0;
        maxIter          1000;
        tolerance        1e-06;
        relTol           0.001;
    }

    omega
    {
           solver           PBiCG;
        preconditioner   DILU;

        minIter          0;
        maxIter          1000;
        tolerance        1e-06;
        relTol           0.001;
    }
 epsilon
    {
         solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-20;
        relTol          1e-01;
    }
}


potentialFlow
{
    nNonOrthogonalCorrectors 20;
    pRefCell        0;
    pRefValue       0;
}


SIMPLE
{
    nCorrectors 0;
    nInitialNonOrthogonalCorrectors 20;
    nNonOrthogonalCorrectors 0;
    //pRefPoint (1 1 0);
    pRefCell        0;    
    pRefValue 0;
 residualControl
    {
        p               1e-9;
        U               1e-10;
        "(k|epsilon|omega)" 1e-10;
    }
}

relaxationFactors
{
    p               0.3; //era 0.2
    U               0.5;
    k               0.5;
    omega        0.5;
}

Thank you for your time RodriguezFatz.
Milad

[miladrakhsha]

I gave the scheme you told me a shot but an error is returned :

--> FOAM FATAL IO ERROR: 
unknown grad scheme edgeCellsLeastSquares

Valid grad schemes are :

9
(
fourth
cellMDLimited
Gauss
cellLimited
beGauss
faceMDLimited
faceLimited
extendedLeastSquares
leastSquares
)


file: /home/milad/Desktop/IBMVALIDATION/system/fvSchemes::gradSchemes::grad(omega) at line 26.

[RodriguezFatz]

Ok, then try leastSquares instead, I didn't know your version is missing that.

Are you sure you use the correct syntax for relaxation factors? I just remember, that different solvers need different syntax. Did you try to use
"(p)" 0.3;
...
?