[Eko]

Hey guys,

I have a problem using snappyHexMesh. I am trying to mesh a geometry with 7 regions but one region doesn't get meshed.
I once had the same problem and solved it somehow but now I have no clue. Tried changing parameters in SHM dict file - without any success.
Does anyone have the same problem or an idea how to solve it?

Introducing zones for interfaces
--------------------------------

Setting cellZones according to named surfaces:
Surface : B1600-12
    faceZone : B1600-12
    cellZone : B1600-12
Surface : Block-1
    faceZone : Block-1
    cellZone : Block-1
Surface : Block-2
    faceZone : Block-2
    cellZone : Block-2
Surface : Block-3
    faceZone : Block-3
    cellZone : Block-3
Surface : Block-4
    faceZone : Block-4
    cellZone : Block-4
Surface : Block-5
    faceZone : Block-5
    cellZone : Block-5
Surface : Air
    faceZone : Air
    cellZone : Air

Setting cellZones according to locationsInMesh:
Location : (0 0 0)
    cellZone : none

For cellZone none found point (0 0 0) in global region 0 out of 1 regions.
Found 7 closed, named surfaces. Assigning cells in/outside these surfaces to the corresponding cellZone.

Walking from known cellZones; crossing a faceZone face changes cellZone

Only keeping zone faces inbetween different cellZones.

Setting faceZones according to neighbouring cellZones:

CellZones:
    Umgebung    size:7246
    B1600-12   size:0
    Block-1     size:8
    Block-2     size:4
    Block-3     size:8
    Block-4     size:7
    Block-5     size:8
    Air size:733

FaceZones:
    B1600-12   size:122
    Block-1     size:8
    Block-2     size:4
    Block-3     size:9
    Block-4     size:13
    Block-5     size:11
    Air size:377

Edge intersection testing:
    Number of edges             : 25589
    Number of edges to retest   : 0
    Number of intersected edges : 733

And my Dict file

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  plus                                  |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      snappyHexMeshDict;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// Which of the steps to run
castellatedMesh true;
snap            true;
addLayers       false;


// Geometry. Definition of all surfaces. All surfaces are of class
// searchableSurface.
// Surfaces are used
// - to specify refinement for any mesh cell intersecting it
// - to specify refinement for any mesh cell inside/outside/near
// - to 'snap' the mesh boundary to the surface
geometry
{

    B-1600-klein-1.stl
    {
        type triSurfaceMesh;
        name B1600-12;
	scale 0.001;
    }

    Block-klein-1.stl
    {
        type triSurfaceMesh;
        name Block-1;
	scale 0.001;
    }

    Block-klein-2.stl
    {
        type triSurfaceMesh;
        name Block-2;
	scale 0.001;
    }

    Block-klein-3.stl
    {
        type triSurfaceMesh;
        name Block-3;
	scale 0.001;
    }

    Block-klein-4.stl
    {
        type triSurfaceMesh;
        name Block-4;
	scale 0.001;
    }

    Block-klein-5.stl
    {
        type triSurfaceMesh;
        name Block-5;
	scale 0.001;
    }
 
    Air-klein.stl
    {
	type triSurfaceMesh;
	name Air;
	scale 0.001;
    }
};



// Settings for the castellatedMesh generation.
castellatedMeshControls
{

    // Refinement parameters
    // ~~~~~~~~~~~~~~~~~~~~~

    // If local number of cells is >= maxLocalCells on any processor
    // switches from from refinement followed by balancing
    // (current method) to (weighted) balancing before refinement.
    maxLocalCells 100000;

    // Overall cell limit (approximately). Refinement will stop immediately
    // upon reaching this number so a refinement level might not complete.
    // Note that this is the number of cells before removing the part which
    // is not 'visible' from the keepPoint. The final number of cells might
    // actually be a lot less.
    maxGlobalCells 300000;

    // The surface refinement loop might spend lots of iterations
    // refining just a few cells. This setting will cause refinement
    // to stop if <= minimumRefine are selected for refinement. Note:
    // it will at least do one iteration (unless the number of cells
    // to refine is 0)
    minRefinementCells 3;

    // Number of buffer layers between different levels.
    // 1 means normal 2:1 refinement restriction, larger means slower
    // refinement.
    nCellsBetweenLevels 6;



    // Explicit feature edge refinement
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    // Specifies a level for any cell intersected by its edges.
    // This is a featureEdgeMesh, read from constant/triSurface for now.
    features
    (
    );



    // Surface based refinement
    // ~~~~~~~~~~~~~~~~~~~~~~~~

    // Specifies two levels for every surface. The first is the minimum level,
    // every cell intersecting a surface gets refined up to the minimum level.
    // The second level is the maximum level. Cells that 'see' multiple
    // intersections where the intersections make an
    // angle > resolveFeatureAngle get refined up to the maximum level.

    refinementSurfaces
    {

        B1600-12
        {
            level ( 1 3 );

            cellZone B1600-12;
            faceZone B1600-12;           
	    cellZoneInside inside;
        }

        Block-1
        {
            level ( 1 1 );

            cellZone Block-1;
            faceZone Block-1;
            cellZoneInside inside;
        }

        Block-2
        {
            level ( 1 1 );

            cellZone Block-2;
            faceZone Block-2;
            cellZoneInside inside;
        }

        Block-3
        {
            level ( 1 1 );

            cellZone Block-3;
            faceZone Block-3;
            cellZoneInside inside;
        }

        Block-4
        {
            level ( 1 1 );

            cellZone Block-4;
            faceZone Block-4;
            cellZoneInside inside;
        }

        Block-5
        {
            level ( 1 1 );

            cellZone Block-5;
            faceZone Block-5;
            cellZoneInside inside;
        }
	
	Air
	{
	    level ( 1 3 );
	    
	    cellZone Air;
	    faceZone Air;
            cellZoneInside inside;
         }

    }

    // Resolve sharp angles
    resolveFeatureAngle 60;


    // Region-wise refinement
    // ~~~~~~~~~~~~~~~~~~~~~~

    // Specifies refinement level for cells in relation to a surface. One of
    // three modes
    // - distance. 'levels' specifies per distance to the surface the
    //   wanted refinement level. The distances need to be specified in
    //   descending order.
    // - inside. 'levels' is only one entry and only the level is used. All
    //   cells inside the surface get refined up to the level. The surface
    //   needs to be closed for this to be possible.
    // - outside. Same but cells outside.

    refinementRegions
    {
		
    }


    // Mesh selection
    // ~~~~~~~~~~~~~~

    // After refinement patches get added for all refinementSurfaces and
    // all cells intersecting the surfaces get put into these patches. The
    // section reachable from the locationInMesh is kept.
    // NOTE: This point should never be on a face, always inside a cell, even
    // after refinement.
    locationInMesh 
    (0.02 0.02 0.05);


    // Whether any faceZones (as specified in the refinementSurfaces)
    // are only on the boundary of corresponding cellZones or also allow
    // free-standing zone faces. Not used if there are no faceZones.
    allowFreeStandingZoneFaces false;
}



// Settings for the snapping.
snapControls
{
    //- Number of patch smoothing iterations before finding correspondence
    //  to surface
    nSmoothPatch 4;

    //- Relative distance for points to be attracted by surface feature point
    //  or edge. True distance is this factor times local
    //  maximum edge length.
    tolerance 1.5;

    //- Number of mesh displacement relaxation iterations.
    nSolveIter 150;

    //- Maximum number of snapping relaxation iterations. Should stop
    //  before upon reaching a correct mesh.
    nRelaxIter 5;

    // Feature snapping

        //- Number of feature edge snapping iterations.
        //  Leave out altogether to disable.
        nFeatureSnapIter 4;

        //- Detect (geometric) features by sampling the surface
        implicitFeatureSnap true;

        //- Use castellatedMeshControls::features
        explicitFeatureSnap false;

        //- Detect features between multiple surfaces
        //  (only for explicitFeatureSnap, default = false)
        multiRegionFeatureSnap false;
}



// Settings for the layer addition.
addLayersControls
{
    relativeSizes true;

    // Per final patch (so not geometry!) the layer information
    layers
    {
    }

    // Expansion factor for layer mesh
    expansionRatio 1.3;

    // Wanted thickness of final added cell layer. If multiple layers
    // is the thickness of the layer furthest away from the wall.
    // Relative to undistorted size of cell outside layer.
    // See relativeSizes parameter.
    finalLayerThickness 1;

    // Minimum thickness of cell layer. If for any reason layer
    // cannot be above minThickness do not add layer.
    // Relative to undistorted size of cell outside layer.
    minThickness 0.1;

    // If points get not extruded do nGrow layers of connected faces that are
    // also not grown. This helps convergence of the layer addition process
    // close to features.
    // Note: changed(corrected) w.r.t 17x! (didn't do anything in 17x)
    nGrow 0;

    // Advanced settings

    // When not to extrude surface. 0 is flat surface, 90 is when two faces
    // are perpendicular
    featureAngle 30;

    // Maximum number of snapping relaxation iterations. Should stop
    // before upon reaching a correct mesh.
    nRelaxIter 6;

    // Number of smoothing iterations of surface normals
    nSmoothSurfaceNormals 1;

    // Number of smoothing iterations of interior mesh movement direction
    nSmoothNormals 3;

    // Smooth layer thickness over surface patches
    nSmoothThickness 2;

    // Stop layer growth on highly warped cells
    maxFaceThicknessRatio 0.5;

    // Reduce layer growth where ratio thickness to medial
    // distance is large
    maxThicknessToMedialRatio 1;

    // Angle used to pick up medial axis points
    // Note: changed(corrected) w.r.t 17x! 90 degrees corresponds to 130 in 17x.
    minMedianAxisAngle 90;

    // Create buffer region for new layer terminations
    nBufferCellsNoExtrude 0;

    // Overall max number of layer addition iterations. The mesher will exit
    // if it reaches this number of iterations; possibly with an illegal
    // mesh.
    nLayerIter 30;
}



// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
    #include "meshQualityDict"

    // Advanced

    //- Number of error distribution iterations
    nSmoothScale 4;
    //- Amount to scale back displacement at error points
    errorReduction 0.75;
}


// Advanced

// Merge tolerance. Is fraction of overall bounding box of initial mesh.
// Note: the write tolerance needs to be higher than this.
mergeTolerance 1e-6;


// ************************************************************************* //