[Giova]

Hi everybody, i need you help for solving a problem.

I try to simulate a vertical wind turbine with the LinearUpwind schemes for the divergense. I have this condition and setting:

Airfoil NACA 0018

wind 8 m/s

the fluid is Incompressible

my fvschemes is:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1606+                                |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default Euler;
}

gradSchemes
{
    default         cellMDLimited  leastSquares 1;
    //grad(p)         cellMDLimited  leastSquares 1;
    //grad(U)         cellMDLimited  leastSquares 1;
}

divSchemes
{
    default         none;
    div(phi,U)      Gauss linearUpwind grad(U);
    div(phi,k)      Gauss linearUpwind grad(k);
    div(phi,omega)  Gauss linearUpwind grad(omega);
    div((nuEff*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear limited corrected 0.5;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default         corrected;
}

wallDist
{
    method meshWave;
}


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

I tried to set the gradSchemes whit Gauss Liner but i didn't solve the problem

and the fvSolution is

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1606+                                |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    pcorr
    {
        solver           GAMG;
        tolerance        0.01;
        relTol           0;
        smoother         GaussSeidel;
        nPreSweeps       0;
        nPostSweeps      2;
        cacheAgglomeration true;
        agglomerator     faceAreaPair;
        nCellsInCoarsestLevel 10;
        mergeLevels      1;
    }

    p
    {
        $pcorr
        tolerance        1e-5;
        relTol           0;
    }

    pFinal
    {
        $p;
        tolerance        1e-5;
        relTol           0;
    }
    
    U
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-06;
        relTol          0;
    }
    
    "(k|omega)"
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-14;
        relTol          1e-06;
    }
    UFinal
    {
        $U;
        tolerance       1e-06;
        relTol          0;
    }
    kFinal
    {
        $k;
        tolerance       1e-30;
        relTol          1e-06;
    }
    omegaFinal
    {
        $omega;
        tolerance       1e-30;
        relTol          1e-06;
    }
    
    cellDisplacement
    {
        solver          GAMG;
        tolerance       1e-5;
        relTol          0;
        smoother        GaussSeidel;
        cacheAgglomeration true;
        nCellsInCoarsestLevel 10;
        agglomerator    faceAreaPair;
        mergeLevels     1;
    }
}

PIMPLE
{
    correctPhi          yes;
    nOuterCorrectors    25;
    nCorrectors         2;
    nNonOrthogonalCorrectors 0;
}

relaxationFactors
{
    fields
    {
        p               0.3;
    }
    equations
    {
        "(U|k|omega)"   0.7;
        "(U|k|omega)Final" 1.0;
    }
}

cache
{
    grad(U);
}

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

.

my timeStep is 2E-4.

I identified the problem in the variable omega (I use k-omega SST) as you can see in the immagine; the variable hire an incorrect value during the iteration in the cell near the shear and after some timestep the simulation diverge.
It's doesn't happen if I use a smaller timeStep (2E-5)


Thanks