CFD Online Discussion Forums - 2D Waveflume:Bad waves due to symmetryPlane + k-epsilon?

Hey guys,

I am trying to simulate a pitching floater in a 2D waveflume with ihDyMFoam.
For now I am simulating the flume without the floater and with ihFoam because I had problems with the waves just disappearing on the way.
The wave has the following properties:

Code:

IH Wave Generation BC

Wave theory: StokesII

H: 0.06

T: 1

h: 0.775

L: 1.55536

Direction: 0º

Generation in: Intermediate waters.

Relative depth (kh): 3.13076

I simulated 3 different cases:
*1* laminar case with front and backside empty
*2* turbulent case with front and backside empty
*3* turbulent case with front and backside symmetryPlane

I attached a plot of the amplitude over space for all three cases after 20s. Actually I realized that even the laminar case doesn't look that good, so probably I have some mistake in my fvSchemes, fvSolution or IHWavesDict.
But anyway the results are getting much worse when I add turbulence, especially for case *3*.

On the waves2foam thread Niels wrote:
" Well the short answer is yes that turbulence models have been coupled with waveFoam, however, if you strictly stick to the turbulence formulations in OpenFoam, you will get poor results, as the turbulence formulation in OF does not consider the density in the equations, hence excessive diffusion of turbulence takes place over the interface, which results in rapid decay in the wave height.

Therefore, you need to formulate the turbulence equations correctly, namely including density in the turbulence equations. "

Could this be the reason? Will I face the same problems when using ihFoam?

I'll be grateful for any suggestions! :)
Cheers,
Mona

IHWavesDict:

Code:

waveType        regular;



waveTheory      StokesII;



genAbs          1;



absDir          0.0;



nPaddles        1;



wavePeriod      1.0;



waveHeight      0.06;



waveDir         0.0;



wavePhase       0.0;



tSmooth         0.0;

fvSchemes:

Code:

ddtSchemes

{

    default         Euler;

}



gradSchemes

{

    default         Gauss linear;

}



divSchemes

{

    div(rhoPhi,U)  Gauss limitedLinearV 1;

    div(U)  Gauss linear;

    div((rhoPhi|interpolate(porosity)),U)  Gauss limitedLinearV 1;

    div(rhoPhiPor,UPor)  Gauss limitedLinearV 1;

    div(rhoPhi,UPor)  Gauss limitedLinearV 1;

    div(rhoPhiPor,U)   Gauss limitedLinearV 1; 

    div(phi,alpha)  Gauss vanLeer01;

    div(phirb,alpha) Gauss interfaceCompression;

    div((muEff*dev(T(grad(U))))) Gauss linear;

    div(phi,k)      Gauss upwind;

    div(phi,epsilon) Gauss upwind;

    div((phi|interpolate(porosity)),k)      Gauss upwind;

    div((phi|interpolate(porosity)),epsilon) Gauss upwind;

    div(phi,omega) Gauss upwind;

    div((phi|interpolate(porosity)),omega) Gauss upwind;

}



laplacianSchemes

{

    default         Gauss linear corrected;

}



interpolationSchemes

{

    default         linear;

}



snGradSchemes

{

    default         corrected;

}



fluxRequired

{

    default         no;

    p_rgh;

    pcorr;

    alpha.water;

}

fvSolution:

Code:

solvers

{

    "alpha.water.*"

    {

        nAlphaCorr      1;

        nAlphaSubCycles 2;

        alphaOuterCorrectors yes;

        cAlpha          1;



        MULESCorr       no;

        nLimiterIter    3;



        solver          smoothSolver;

        smoother        symGaussSeidel;

        tolerance       1e-8;

        relTol          0;

    }



    pcorr

    {

        solver          PCG;

        preconditioner  DIC;

        tolerance       1e-5;

        relTol          0;

    }



    p_rgh

    {

        solver          PCG;

        preconditioner  DIC;

        tolerance       1e-07;

        relTol          0.05;

    }



    p_rghFinal

    {

        $p_rgh;

        relTol          0;

    }



    U

    {

        solver          smoothSolver;

        smoother        symGaussSeidel;

        tolerance       1e-06;

        relTol          0;

    }



    "(U|k|epsilon)"

    {

        solver          PBiCG;

        preconditioner  DILU;

        tolerance       1e-06;

        relTol          0;

    }



    "(U|k|epsilon)Final"

    {

        solver          PBiCG;

        preconditioner  DILU;

        tolerance       1e-08;

        relTol          0;

    }

}



PIMPLE

{

    momentumPredictor   no;

    nOuterCorrectors    1;

    nCorrectors         3;

    nNonOrthogonalCorrectors 0;

}



relaxationFactors

{

    fields

    {

    }

    equations

    {

        ".*" 1;

    }

}