[OpenFOOL]

Hi folks,


first of all I want to say that this forum helped me a lot already just by reading threads. Unfortunately I have to open my first thread, because I despair of using SnappyHexMesh with my geometry. Originally I use several STL files which form a pump passage geometry (therefore it´s more complex), but to make things as simple as possible I will use another geometry to describe the problems I am facing. I get the same "problematic" results with those geometrys.

The main problem is SnappyHexMesh not snapping to the edges in a reliable manner.

The white lines represent the detected feature edges. So every edge was detected correctly. But SHM fails at the snapping process, see pictures below. My settings are as follows...

castellatedMeshControls
{
    maxLocalCells 100000;
    maxGlobalCells 2000000;
    minRefinementCells 0;
    maxLoadUnbalance 0.1;
    nCellsBetweenLevels 2;

    features
    (

    {
            file        "model1c.eMesh";
            level       3;
        }

    );

refinementSurfaces
    {
        model1c
        {
            level       (2 2);
        }
    }

snapControls
{
    nSmoothPatch 4;
    tolerance 5;
    nSolveIter 300;
    nRelaxIter 5;
    nFeatureSnapIter 10;
    implicitFeatureSnap false;
    explicitFeatureSnap true;
    multiRegionFeatureSnap true;
}

Apparently it does not matter what settings I use. Sometimes I get a slightly better result but those defects won´t disappear completely. At the inlet of the pump are four rippled locations, all 90° apart. Those ones seem to be too far away for SHM to snap to the edge (castellated circle, so there are 4 locations of the same distance to the edge, see Pumpe_2.jpeg). But changing the tolerance won´t let them disappear.

Does somebody see my mistake? It´s a quite common geometry, so I think it should be possible to mesh it with SHM. If you have any idea or suggestion or if you need more information, please let me know. Many thanks in advance.


Leon


Edit: I am stupid. I wondered why there's no surface refinement step in my castellated mesh. I looked at the number of cells...they are above the maximum global cells. So SHM won't be refine anything at all. Now I used a higher maximum global cells setting and got better results, but defects are still there. Maybe I am on the right way at least.