[jessica_ict]

Dear all,
I have a problem with deep water simulation.
Wavelength would become larger as wave propagation.
Could someone tell me how to solve the problem?

The following are my file:

waveProperties:

seaLevel	0.00;

// A list of the relaxation zones in the simulation. The parameters are given
// in <name>Coeffs below.
relaxationNames (inlet outlet);

initializationName outlet;

inletCoeffs
{
    // Wave type to be used at boundary "inlet" and in relaxation zone "inlet"
    waveType    stokesSecond;  
    
    // Ramp time of 2 s
    Tsoft       1.2;

    // Water depth at the boundary and in the relaxation zone
    depth       0.900000;

    // Wave period
    period      1.20;

    // Phase shift in the wave
    phi         0.000000;

    // Wave number vector, k. 
    direction  (1.0 0.0 0.0);

    // Wave height
    height      0.06;
    debug       false;
    
    // Specifications on the relaxation zone shape and relaxation scheme
    relaxationZone
    {
        relaxationScheme Spatial;
        relaxationShape  Rectangular;
        beachType        Empty;
    
        relaxType   INLET;
        startX      (0.0  0.0 -0.9);
        endX        (6.0  0.9  0.3);
        orientation      (1.0 0.0 0.0);
    }
};

outletCoeffs
{
    waveType    potentialCurrent;
    U           (0 0 0);
    Tsoft      	1.2;

    relaxationZone
    {
        relaxationScheme Spatial;
        relaxationShape  Rectangular;
        beachType        Empty;    

        relaxType   OUTLET;
        startX      (29.0  0.0 -0.9);
        endX        (35.0  0.9  0.3);
        orientation      (1.0 0.0 0.0);
    }
};

controlDict:

application interFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         60;

deltaT          0.001;

writeControl    adjustableRunTime;

writeInterval   0.1;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression uncompressed;

timeFormat      general;

timePrecision   6;

runTimeModifiable yes;

adjustTimeStep  yes;

maxCo           0.25;

maxAlphaCo      0.25;

maxDeltaT       0.001;

fvSolution

solvers
{
    "alpha.water.*"
    {
        nAlphaCorr      1;
        nAlphaSubCycles 1;
        alphaOuterCorrectors yes;
        cAlpha          1;

        MULESCorr       yes;
        nLimiterIter    3;

        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-8;
        relTol          0;
    }

    pcorr GAMG
    {
        tolerance        1e-7;
        relTol           0.0;

        smoother         DIC;//GaussSeidel;
        nPreSweeps       0;
        nPostSweeps      2;
        nFinestSweeps    2;

        cacheAgglomeration true;
        nCellsInCoarsestLevel 10;
        agglomerator     faceAreaPair;
        mergeLevels      1;
    };

    pcorrFinal GAMG
    {
        tolerance        1e-7;
        relTol           0.0;

        smoother         DIC;//GaussSeidel;
        nPreSweeps       0;
        nPostSweeps      2;
        nFinestSweeps    2;

        cacheAgglomeration true;
        nCellsInCoarsestLevel 10;
        agglomerator     faceAreaPair;
        mergeLevels      1;
    };

    p_rgh GAMG
    {
        tolerance        1e-7;
        relTol           0.0;

        smoother         DIC;//GaussSeidel;
        nPreSweeps       0;
        nPostSweeps      2;
        nFinestSweeps    2;

        cacheAgglomeration true;
        nCellsInCoarsestLevel 10;
        agglomerator     faceAreaPair;
        mergeLevels      1;
    };

    p_rghFinal GAMG
    {
        tolerance        1e-8;
        relTol           0.0;

        smoother         DIC;//GaussSeidel;
        nPreSweeps       0;
        nPostSweeps      2;
        nFinestSweeps    2;

        cacheAgglomeration true;
        nCellsInCoarsestLevel 10;
        agglomerator     faceAreaPair;
        mergeLevels      1;
    };

    U PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-09;
        relTol           0;
    };

    UFinal PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-09;
        relTol           0;
    };

    gamma PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-07;
        relTol           0;
    };
}


PIMPLE 
{ 
    momentumPredictor yes;
    nOuterCorrectors 1; 
    nCorrectors     3;
    nNonOrthogonalCorrectors 1;
}

relaxationFactors
{
    fields
    {
    }
    equations
    {
        ".*" 1;
    }
}

fvScheme

ddtSchemes
{
    default Euler;
}

gradSchemes
{
//    default	cellLimited fourth 1;
    default         Gauss linear;
    grad(U)         Gauss linear;
    grad(alpha1)     Gauss linear;
}

divSchemes
{
//    default	    Gauss linear;
    div(rhoPhi,U)  Gauss limitedLinearV 1;
//    div(phi,gamma)  Gauss vanLeer;
//    div(rho*phi,U)  Gauss MUSCL;
//    div((muEff*dev(T(grad(U))))) Gauss linear;
    div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;
    div(phi,alpha)  Gauss MUSCL;
    div(phirb,alpha) Gauss interfaceCompression;
//    div(rhoPhi,U)   Gauss limitedLinearV 1;
}

laplacianSchemes
{
    default         Gauss linear corrected;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default         corrected;
}

fluxRequired
{
    default         no;
    p_rgh;
    pcorr;
    alpha.water;
}

domain
x:35m z:1.2m
dx:0.005m dz:0.0025

wave condition
period:1.2 sec
wave height:0.06m
water depth:0.9m
This is deep water condition!
There are 24 cells per wave height and about 439 cells per wavelength.

I tried two versions of OpenFOAM (1712plus and extend 4.0), different types of mesh and different timesteps.

The result of different timesteps, version and mesh type shown below: