[mgdenno]

Hello,

As indicated in the post title, I am trying to use groovyBC to set the inlet boundary condition for a interFoam simulation. I am using OpenFOAM 2.1.0 running on kubuntu 11.10. The attached picture (colored as p_rgh) shows a 2D view of the problem which is flow in a channel over a spillway. The inlet is on the right, the outlet is on the left, top is atmosphere, bottom is wall, and front and back are symmetry plane. Historically I have split my inlet patch into 2 separate patches, one for air and one for water. I was hoping that I would be able to use groovyBC to accomplish the same thing with one patch so that I can change the inlet water level without changing my mesh. Anyway, the simulation seems to run ok, and the water surface looks ok (although I haven't compared to physical model data yet), but the pressure at the inlet seems to be funky. You can see in the picture that the p_rgh is 0 at the inlet, and p (not shown) has a significant negative pressure at the inlet.

This seems incorrect to me. Can anyone provide any insight regarding what is happening? Are my boundary conditions (below) specified incorrectly?

p_rgh:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.1.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    top
    {
        type            totalPressure;
        p0              uniform 0;
        U               U;
        phi             phi;
        rho             rho;
        psi             none;
        gamma           1;
        value           uniform 0;
    }
    bottom
    {
        type            buoyantPressure;
        value           uniform 0;
    }
    inlet
    {
        type            buoyantPressure;
        value           uniform 0;
    }
    outlet
    {
       type            totalPressure;
       p0              uniform 0;
       U               U;
       phi             phi;
       rho             rho;
       psi             none;
       gamma           1;
       value           uniform 0;
    }
    walls
    {
        type            symmetryPlane;
    }
    wes
    {
        type            buoyantPressure;
        value           uniform 0;
    }
}

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

alpha1:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.1.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      alpha1;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    top
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }
    bottom
    {
        type            zeroGradient;
    }
    inlet
    {
       type             groovyBC;
       valueExpression "1";
       fractionExpression "(pos().z<28) ? 1 : 0";
       value            uniform 1;
    }
    outlet
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }
    walls
    {
        type            symmetryPlane;
    }
    wes
    {
        type            zeroGradient;
    }
}

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

U

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.1.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    location    "0";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    top
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    bottom
    {
        type            slip;
    }
    inlet
    {
       type            groovyBC;
       valueExpression "(pos().z<28) ? vector(1.981,0,0) : vector(0,0,0)";
       value           uniform (0 0 0);
    }
    outlet
    {
        type            inletOutlet;
        inletValue      uniform (0 0 0);
        value           uniform (0 0 0);
    }
    walls
    {
        type            symmetryPlane;
    }
    wes
    {
        type            slip;
    }
}


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

Thanks in advance. I look forward to your input.