[vigges]

Hi all,

I'd like to simulate a flow through a symmetric diffuser. So far, it is a 2D problem, although it's going to be extended to a 3D problem.

As you can see on the picture, my flow sticks to one wall what isn't exactly what I have expected.
The topPatch and bottomPatch are missing on the picture due to the dump's size.

I use simpleFoam (kOmegaSST) in OF 2.1.0 and following BCs:

U

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

internalField   uniform (0 0 0);

boundaryField
{

    inletPatch
    {
        type                        mapped;
        value                       uniform (30.22 0 0);
        interpolationScheme   cell;
        setAverage               true;
        average                    (30.22 0 0);    
    }    
    
    allWallPatches
    {
        type                        fixedValue;
        value                       uniform (0 0 0);    
    }
    
    topPatch //outlet
    {
        type                        zeroGradient;
    }

    bottomPatch //outlet
    {
        type                        zeroGradient;
  }

    frontPatch
    {
        type                        empty;
    }

    backPatch
    {
        type                        empty;
    }

}

p

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

internalField   uniform 0;

boundaryField
{

    inletPatch
    {
        type                        zeroGradient;
    }    

    allWallPatches
    {
        type                        zeroGradient;
    }
    
    topPatch //outlet
    {
        type                        fixedValue;
        value                       uniform 0;
    }

    bottomPatch //outlet
    {
        type                        fixedValue;
        value                       uniform 0;
    }

    frontPatch
    {
        type                        empty;
    }

    backPatch
    {
        type                        empty;
    }

}

nut

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

internalField   uniform 0;

boundaryField
{

    inletPatch
    {
        type                        calculated;
        value                       uniform 0;
    }    
    
    allWallPatches
    {
        type                        nutkWallFunction;
        value                       uniform 0;
    }

    topPatch //outlet
    {
        type                        calculated;
        value                       uniform 0;
    }

    bottomPatch //outlet
    {
        type                        calculated;
        value                       uniform 0;
    }

    frontPatch
    {
        type                        empty;
    }

    backPatch
    {
        type                        empty;
    }

}

k

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

internalField   uniform 2.949;

boundaryField
{

    inletPatch
    {
        type                        fixedValue;
        value                       uniform 2.949;
    }    
    
    allWallPatches
    {
        type                        kqRWallFunction;
        value                       uniform 0;
    }

    topPatch //outlet
    {
        type                        zeroGradient;
    }

    bottomPatch //outlet
    {
        type                        zeroGradient;
    }

    frontPatch
    {
        type                        empty;
    }

    backPatch
    {
        type                        empty;
    }

}

omega

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

internalField   uniform 111.1;

boundaryField
{

    inletPatch
    {
        type                        fixedValue;
        value                       uniform 111.1;
    }    
    
    allWallPatches
    {
        type                        omegaWallFunction;
        value                       uniform 0;
    }

    topPatch //outlet
    {
        type                        zeroGradient;
    }

    bottomPatch //outlet
    {
        type                        zeroGradient;
    }

    frontPatch
    {
        type                        empty;
    }

    backPatch
    {
        type                        empty;
    }

}

Maybe someone has an idea how to fix this.
Thanks