[robbirobocop]

Dear Foamers,

in the last weeks I tried to successfully use bubbleFoam to simulation multiphase flow inside a steamdrum. After finally getting the simulation more or less stable - the timeStep and maxCo are still very low - yet another problem occurs.

I am loosing water. There is one inlet where a steam water mixture is put in. After some time that is 0.05 s in the attached picture it seems like only steam was put in and not a mixture...

And I have no idea what BC or scheme or whatever arouses this problem. It seems that steam only pushes away the water level that was initialised with setFields. No separation takes place.

The used fvSchemes and fvSolution entries are as follows:

fvSchemes

ddtSchemes
{
    default         Euler;
}
gradSchemes
{
    default         Gauss linear;
}
divSchemes
{
    default         none;
    div(phia,Ua)    Gauss upwind;
    div(phib,Ub)    Gauss upwind;
    div(phib,k)     Gauss upwind;
    div(phib,epsilon) Gauss upwind;
    div(phi,alpha)  Gauss upwind;
    div((-nuEffa*T(grad(Ua)))) Gauss linear;
    div((-nuEffb*T(grad(Ub)))) Gauss linear;
}
laplacianSchemes
{
    default         Gauss linear corrected;
}
interpolationSchemes
{
    default         linear;
}
snGradSchemes
{
    default         corrected;
}
fluxRequired
{
    default         no;
    p               ;
}

fvSolution

solvers
{
    p
    {
        solver          GAMG;
        tolerance       1e-04;
        relTol          0.1;
        smoother        DIC;
        nPreSweeps      0;
        nPostSweeps     2;
        nFinestSweeps   2;
        cacheAgglomeration true;
        nCellsInCoarsestLevel 10;
        agglomerator    faceAreaPair;
        mergeLevels     1;
    }
    pFinal
    {
        $p;
        tolerance       1e-04;
        relTol          0;
    }
       "(k|epsilon)"
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-4;
        relTol          0.0;
    }
    "(k|epsilon)Final"
    {

        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-4;
        relTol          0.0;
    }
    alpha
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-5;
        relTol          0.1;
    }
    alphaFinal
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-5;
        relTol          0;
    }
}
    nCorrectors     1; //1
    nNonOrthogonalCorrectors 1;
    nAlphaCorr      1;
    correctAlpha    yes;

The BC for the INLET is alpha of 0.6, Ua with ~6 m/s, Ub with ~4 m/s and p is of course zeroGradient. K and epsilon are calculated with the typical formulaes and set to a fixedValue. A normal water level is set with setFields. Thus, half of the geometry is filled with water.

The problem occurs 2D as well as 3D, laminar and turbulent...
The picture that is attached, illustrates the "loosing of the fluid"... (right side / patch)

Any idea or help would be very appreciated.

Thanks.