[cbe]

Dear all,

I have recently started to get into SHM but am having problems with not being able to resolve component edges cleanly and not being able to snap to them. I am trying to mesh a fan and getting these problems on the trailing edge.

with surfaceFeatures i am capturing the edges by defining an angle. With paraview i checked if i got the edges of interest correctly (attached PNG, red lines are from the .obj, grey is the stl body). This does all seem correct.
in shmDict i use castellatedMeshControls / features to refine around those edges

Here's my surfaceFeaturesDict code

FoamFile

{

    format      ascii;

    class       dictionary;

    object      surfaceFeaturesDict;

}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
surfaces ("fan.stl");
includedAngle   130;
writeObj         yes;

snappyHexMeshDict:

FoamFile

{

    format      ascii;

    class       dictionary;

    object      snappyHexMeshDict;

}





castellatedMesh true;

snap            true;

addLayers       false;





geometry

{

    fan

    {

        type triSurfaceMesh;

        file "fan.stl";

    }





};







castellatedMeshControls

{





    maxLocalCells 1000000;

    maxGlobalCells 20000000;

    minRefinementCells 0;

    nCellsBetweenLevels 1;







    features

    (

        {

            file "fan.extendedFeatureEdgeMesh";

            level 5;

        }

    );



    refinementSurfaces

    {

        fan

        {

            // Surface-wise min and max refinement level

            level (4 4);

        }

    }



    resolveFeatureAngle 30;



    locationInMesh (0.00 0.00 0.27); // Inside point	

    allowFreeStandingZoneFaces true;

}









snapControls

{

    nSmoothPatch 3;

    tolerance 1.0;

    nSolveIter 300;

    nRelaxIter 5;

    nFeatureSnapIter 30;

    implicitFeatureSnap false;

    explicitFeatureSnap true;

    multiRegionFeatureSnap false;

}





.

.

.

I tryed to get a better solution with different settings

• played around with level of "fan.extendedFeatureEdgeMesh" from 5 to 10

• different refinement levels on surface

• resolveFeatureAngle 5-30

• nFeatureSnapIter 5-30

At first i thought it might be a problem with the very thin surface on the trailing edge, but i also get crinkles on the edges of the airfoil profile itself.

Do the more experienced users still have one or two tips that I could test? I would be very happy about any help.

Thanks.