[Noémie]

Dear users,

I'm taking a case where I found on the youtube for generating a hydraulic jump in a flat bottom. I'm using foam-extend-3.1. The original files I got from the poster on Youtube don't work for me (I think it is the version problem), so I made some changes to let the case running.

But the backwater can never reaches to the base flow, see the figures. (Fig.1 is the initial alpha1 and Fig.2 is the alpha1 after running 1s).

For the mesh, both inlet and outlet are seperated to water and air part.

Here is the BC for fields:

PHP Code:

alpha1:
boundaryField
{
    inlet_water
    {
        type            fixedValue;
        value           uniform 1;
    }
    inlet_air
    {
        type            outletInlet;
        outletValue      uniform 0;
        value           uniform 0;
    }
    outlet_water
    {
        type            inletOutlet;
        inletValue      uniform 1;
        value           uniform 0;
    }
    outlet_air
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }
    atmosphere
    {
        type            zeroGradient;
    }
    walls
    {
        type            zeroGradient;
    }
    front
    {
        type            empty;
    }
    back
    {
        type            empty;
    }
}

U:
boundaryField
{
    inlet_water
    {
        type            fixedValue;
        value           uniform (13 0 0);
    }
    inlet_air
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    outlet_water
    {
        type            zeroGradient;
    }
    outlet_air
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    atmosphere
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    walls
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    front
    {
        type            empty;
    }
    back
    {
        type            empty;
    }
}

pd:
boundaryField
{
    inlet_water
    {
        type            buoyantPressure;
        gradient        uniform 0;
        rho             rho;
        value           uniform 0;

    }

    inlet_air
    {
        type            totalPressure;
        rho             rho;
        psi             none;
        gamma           1;
        p0              uniform 0;
        value           uniform 0;
    }

    outlet_water
    {
        type            buoyantPressure;
        gradient        uniform 0;
        rho             rho;
        value           uniform 0;
    }

    outlet_air
    {
        type            totalPressure;
        rho             rho;
        psi             none;
        gamma           1;
        p0              uniform 0;
        value           uniform 0;
    }

    walls
    {
        type            buoyantPressure;
        gradient        uniform 0;
        rho             rho;
        value           uniform 0;
    }

    atmosphere
    {
        type            totalPressure;
        rho             rho;
        psi             none;
        gamma           1;
        p0              uniform 0;
        value           uniform 0;
    }

    "front|back"
    {
        type            empty;
    }
} 


I tried to change a lot with BC but it dosen't help. I do really need your help.
Thanks!

Hao