[zhxter]

Dear foamers,
I am now trying to generate regular waves using the tutorial "waveFlume" of waves2Foam. And the result shows that the value of wave crest is larger than the wave trough. ( asymmetrical against the still water level). The relevant input files are shown as follows:

1. blockMesh

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.5                                   |
|   \\  /    A nd           | Web:      http://www.OpenFOAM.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices        
(
    (  0   -1.035 0 )
    ( 13.5 -1.035 0 )
    (  0   -0.10  0 )
    ( 13.5 -0.10  0 )
    (  0    0.10  0 )
    ( 13.5  0.10  0 )
    (  0    0.265 0 )
    ( 13.5  0.265 0 )

    (  0   -1.035 0.1 )
    ( 13.5 -1.035 0.1 )
    (  0   -0.10  0.1 )
    ( 13.5 -0.10  0.1 )
    (  0    0.10  0.1 )
    ( 13.5  0.10  0.1 )
    (  0    0.265 0.1 )
    ( 13.5  0.265 0.1 )                  
);

blocks          
(
    hex (0 1 3 2 8 9 11 10)   (1000 46 1 ) simpleGrading (1 0.3333 1)
    hex (2 3 5 4 10 11 13 12) (1000 20 1) simpleGrading (1 1 1)
    hex (4 5 7 6 12 13 15 14) (1000 11 1) simpleGrading (1 2 1)
);

edges           
(
);

patches         
(
    patch inlet
    (
        (2 0 8 10)
        (4 2 10 12)
        (6 4 12 14)
    )
    wall bottom 
    (
        (0 1 9 8)
    )
    patch outlet
    (
        (1 3 11 9)
        (3 5 13 11)
        (5 7 15 13)
    )

    patch atmosphere 
    (
        (7 6 14 15)
    )
    
    empty frontBack
    (
        (8 9 11 10)
        (10 11 13 12)
        (12 13 15 14)
        (0 2 3 1)
        (2 4 5 3)
        (4 6 7 5)
    )
);

mergePatchPairs
(
);

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

2. probeDefinitions

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.5                                   |
|   \\  /    A nd           | Web:      http://www.OpenFOAM.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      loggingProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

surfaceElevationAnyName
{
    type waveGauge;

    pointDistribution lineDistribution;
    N 200;
    linestart (1.5  -0.5 0.05);
    lineend   (11.5 -0.5 0.05);
    add       ( 0 0.7 0);
    axis      y;
    stretch 1;
}


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

3. wavePropertiesinput

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.5                                   |
|   \\  /    A nd           | Web:      http://www.OpenFOAM.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      environmentalProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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"这里同时给出了boudary入口与relaxation zone入口的边界条件，合二为一
    waveType    stokesFirst;  
    
    // Ramp time of 2 s
    Tsoft       1.1;

    // Water depth at the boundary and in the relaxation zone
    depth       1.035;

    // Wave period
    period      1.1;

    // Phase shift in the wave
    phi         0.000000;

    // Wave number vector, k. 
    direction  (3.1415926 0.0 0.0);

    // Wave height
    height      0.16;
    
    // Specifications on the relaxation zone shape and relaxation scheme
    relaxationZone
    {
        relaxationScheme Spatial;
        relaxationShape  Rectangular;
        beachType        Empty;
    
        relaxType   INLET;
        startX      (0 -1.035 0);
        endX        (2 0.265  0.1);
        orientation      (1.0 0.0 0.0);
    }
};

outletCoeffs
{
    waveType    potentialCurrent;
    U           (0 0 0);
    Tsoft       1.1;

    relaxationZone
    {
        relaxationScheme Spatial;
        relaxationShape  Rectangular;
        beachType        Empty;    

        relaxType   OUTLET;
        startX      (9.5 -1.035 0);
        endX        (13.5 0.265 0.1);
        orientation      (1.0 0.0 0.0);
    }
};



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

4. The simulated regular waves
The generated regular wave has the height of 0.18m. We can find from the figure that the wave crest is about 0.1m while the wave trough is about 0.6m. Could anyone help me with the problem?

[SD@TUB]

hi,
You may enlarge your water depth and also vary mesh density. Set-up seems to be OK.
/Stefan

[ngj]

Good afternoon,

@Xiantao: First order wave theory is not applicable. Try inserting your values in one of the many diagrams of applicable wave theories and you will see what I mean.
(Edit: A quick test shows that with a wave height of 0.08 m and stokesSecond you get good results. For larger wave heights, you will need theories of higher order than second)

Kind regards,

Niels