Openfoam, multiphaseInterfoam, non-constant inlet

Question

I run multiphaseInterfoam, and I have trouble with the inlet being non-constant (I want it to be constant.)

Here are my alpha-files\

/--------------------------------- C++ -----------------------------------\

FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object alpha.air; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField { //- Set patchGroups for constraint patches #includeEtc "caseDicts/setConstraintTypes"

inlet
{
    type            alphaContactAngle;
    thetaProperties
    (
        ( freshWater air ) 90 0 0 0
        ( saltWater air ) 90 0 0 0
        ( freshWater saltWater ) 90 0 0 0
    );
    value           uniform 0;
}

outlet

{
    type            alphaContactAngle;
    thetaProperties
    (
        ( freshWater air ) 90 0 0 0
        ( saltWater air ) 90 0 0 0
        ( freshWater saltWater ) 90 0 0 0
    );
    value           uniform 0;

}

    atmosphere
{
    type            inletOutlet;
    inletValue      uniform 1;
    value           uniform 1;
}


barge
{
    type            alphaContactAngle;
    thetaProperties
    (
        ( freshWater air ) 90 0 0 0
        ( saltWater air ) 90 0 0 0
        ( freshWater saltWater ) 90 0 0 0
    );
    value           uniform 0;
} }

alpha.freshwater:

/--------------------------------- C++ -----------------------------------\

FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object alpha.freshWater; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField { //- Set patchGroups for constraint patches #includeEtc "caseDicts/setConstraintTypes"

inlet
{
    type            fixedValue;
    value           $internalField;
}

outlet
{
    type            variableHeightFlowRate;
    lowerBound      0;
    upperBound      1;
    value           $internalField;
}

atmosphere
{
    type            inletOutlet;
    inletValue      $internalField;
    value           $internalField;
}

barge
{
    type            zeroGradient;
} }

alpha.saltWater

FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object alpha.saltWater; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField { //- Set patchGroups for constraint patches #includeEtc "caseDicts/setConstraintTypes"

inlet
{
    type            fixedValue;
    value           $internalField;
}

outlet
{
    type            variableHeightFlowRate;
    lowerBound      0;
    upperBound      1;
    value           $internalField;
}

atmosphere
{
    type            inletOutlet;
    inletValue      $internalField;
    value           $internalField;
}

barge
{
    type            zeroGradient;
} }

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

alphas

/--------------------------------- C++ -----------------------------------\

FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object alphas; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField { //- Set patchGroups for constraint patches #includeEtc "caseDicts/setConstraintTypes"

inlet
{
    type            fixedValue;
    value           $internalField;
}

outlet
{
    type            variableHeightFlowRate;
    lowerBound      0;
    upperBound      1;
    value           $internalField;
}

atmosphere
{
    type            inletOutlet;
    inletValue      $internalField;
    value           $internalField;
}

barge
{
    type            zeroGradient;
} }

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

The above gives the following, wanted, distribtion of fluids for timestep 1

enter image description here

However, after several time the above changes, also at the inlet:

enter image description here

I really don't understand the contactAngle functino used in alpha.air above. I have tried with the following alpha.air

/--------------------------------- C++ -----------------------------------\

FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object alpha.air; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField { //- Set patchGroups for constraint patches #includeEtc "caseDicts/setConstraintTypes"

inlet
{
    type            fixedValue;
    value           $internalField;
}

outlet
{
    type            variableHeightFlowRate;
    lowerBound      0;
    upperBound      1;
    value           $internalField;
}

atmosphere
{
    type            inletOutlet;
    inletValue      $internalField;
    value           $internalField;
}

barge
{
    type            zeroGradient;
} }

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

With the alpha.air above I get a long error message that includes stuff that is interpreted as internet links so that I am not allowed to pulblish them here. The error message can be seen on this link to the CDF-online forum, where I have also have asked this question.

Does anybvody know how to modify the above files to make the distribution of alpha's at the inlet constant?

Answer 1

In the last version of alpa.air I changed from "internalField uniform 0" to "internalField uniform 1", and now the inlet is constant. I think the internalFIeld value has to equal the default value set in setFieldsDict.