[Kbshariff]

Hello Foamers,

I am relatively new to openfoam, my numerical case is a tidal turbine with actuator disc applied using fvOptions source. I use k-E turbulence model

I would like to improve the quality of my results (attached herewith is a comparison with a reference case using fluent).

My mesh is orthogonal mesh hence I used Gauss linear for the gradScheme..

below is my fvScheme

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2006                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default             steadyState;
}

gradSchemes
{
    default             Gauss linear; 
}

divSchemes
{
    default             none;

    div(phi,U)          Gauss linearUpwind grad(U);//Gauss upwind;	//bounded Gauss upwind;
    div(phi,epsilon)    Gauss upwind;					//Gauss upwind;	//bounded Gauss upwind;
    div(phi,k)          Gauss upwind;					//Gauss upwind;	//bounded Gauss upwind;
    div((nuEff*dev2(T(grad(U)))))    Gauss linear;
}

laplacianSchemes
{
    default             Gauss linear limited corrected 0.33;
}

interpolationSchemes
{
    default            linear;
}

snGradSchemes
{
    default            corrected;	// limited corrected 0.33;
}


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

fvSolution

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2006                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p
    {
        solver           GAMG;
        tolerance        1e-7;
        relTol           0.001;
        minIter          5;
        maxIter          100;
        smoother         GaussSeidel; // DIC; //DICGaussSeidel; //FDIC;
        nPreSweeps       1;
        nPostSweeps      3;
        nFinestSweeps    3;
        scaleCorrection true; 
        directSolveCoarsest false;
        cacheAgglomeration on;
        nCellsInCoarsestLevel 50;    // 500
        agglomerator     faceAreaPair;
        mergeLevels      1;    // 3
    }
    
    U
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.01;
        nSweeps          1;
        maxIter	100;
    };




    k
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.01;
        nSweeps          1;
        maxIter	100;
    };


    epsilon
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.01;
        nSweeps          1;
        maxIter	100;
    };
/*
    p
    {
        solver           GAMG;
        tolerance        1e-6;
        relTol           0.001;
        smoother         GaussSeidel;
    }

    U
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.1;
        nSweeps          1;
    }


    k
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.1;
        nSweeps          1;
    }

    epsilon
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.1;
        nSweeps          1;
    }

*/

}

SIMPLE
{
    nNonOrthogonalCorrectors 0;

    residualControl
    {
        p               1e-3;
        U               1e-4;
        "(k|epsilon)"   1e-4;
    }
}

relaxationFactors
{
    fields
    {
        p               0.3;
    }
    equations
    {
        U               0.7;
        k               0.5; //0.7;
        epsilon         0.5; //0.7;
    }
}

cache
{
    grad(U);
}

Thanks

[shock77]

The result look quite good compared with your experiments. Most people would be satisfied with that I guess. I suppose you have achieved grid convergence before doing your final simulations. You can always increase the mesh denisty and do an LES or even an DNS. Also you can improve mesh density at walls and either resolve the boundary layer directly or you use e. g. the k-omega-SST model. There are like 1000 possibilties to do sth better but you have to decide whether you are satisfied with your results or not, since only you know what actually is important in you problem.