[AlmostSurelyRob]

Dear OpenFOAM users and developers,

I am trying to run a simple pipe with constriction and axial symmetry. Something fairly similar to the geometry posted here [1]. The solver I am using is twoPhaseEulerFoam but I observed similar behavior in interFoam too.

My inlet condition is uniform for all quantities and for alpha I am setting something 0.015. The wedge and empty BC are applied on the the sides and at the centre line respectively e.g. my alpha BC looks like this

boundaryField
{
    outlet
    {
        type               inletOutlet;
        inletValue      uniform 0;
    }
    walls
    {
        type               zeroGradient;
    }
    inlet
    {
        type               fixedValue;
        value             uniform 0.02;
    }
    front
    {
        type            wedge;
    }
    back
    {
        type            wedge;
    }
    axis
    {
       type      empty;
    }
}

The problem is that almost immediately the centreline is beginning to produce additional mass. And my alpha distribution begins to look like this



After this all sort of evil begins to occur. Viscosity there goes up, velocity develops a completely different profile than in the 3D case and Co number increases gradually.

I checked the case several times now and a 3D equivalent works. Single phase solvers work with this setup too so my guess is that multiphase solver is the culprit. My guess is that MULES is causing the problem here, but I cannot be sure.

Please let me know if you have any suggestions on how to fix it. Can post a more detailed setup.

[1] http://openfoamwiki.net/index.php/Contrib/MakeAxialMesh