Skew Faces in Mesh
 

Hi All,

I have an issue with 2 skew faces I cannot remove. I've made the mesh as close to a 1:1 ratio as I can, and tried modifying the boundaryskewness and internal skewness but I am left with 2 skew faces regardless of what I try.

I have attached 3 images of the domain, showing the skew faces as a glyph, then what the surface mesh is like. I previously have had no issues with skew faces, but cannot remove these. If anyone can help, that would be greatly appreciated.

The Blockmesh is as follows:

convertToMeters 1;

vertices
(
(60 -2451510 -1765)
(1880 -2451510 -1765)
(1880 -2449793 -1765)
(60 -2449793 -1765)
(60 -2451510 -1400)
(1880 -2451510 -1400)
(1880 -2449793 -1400)
(60 -2449793 -1400)
);

blocks
(
hex (0 1 2 3 4 5 6 7) (10 9 2) simpleGrading (1 1 1) //was13 12 2
);

edges
(
);

boundary
(
outlet
{
type patch;
faces
(
(0 4 7 3)
(1 5 4 0)
);
}

inlet
{
type patch;
faces
(
(2 6 5 1)
(3 7 6 2)
);
}

Mesa
{
type wall;
faces
(
(0 3 2 1)
);
}
top
{
type patch;
faces
(
(4 5 6 7)
);
}
);

mergePatchPairs
(
);

snappyhexMesh is as follows:

castellatedMesh true;
snap true;
addLayers true;

geometry
{

refinementBox
{
type searchableBox;
min (0 -2451600 -2000);
max (1470 -2440000 -1000);
}
Mesa
{
type triSurfaceMesh;
file "NewMesa_STL.stl";
}


};

castellatedMeshControls
{
maxLocalCells 100000000;

maxGlobalCells 200000000;

minRefinementCells 0;

maxLoadUnbalance 0.10;

nCellsBetweenLevels 8;

features
(
{
file "NewMesa_STL.eMesh";
level 2;
}
);

refinementSurfaces
{
Mesa
{
// Surface-wise min and max refinement level
level (5 5);
}

}

// Resolve sharp angles
resolveFeatureAngle 30;


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

refinementRegions
{
/* refinementBox
{
levels ((0 1));
mode inside;
} */
}

locationInMesh (1000 -2450000 -1600);

allowFreeStandingZoneFaces true;
}

snapControls
{

nSmoothPatch 5;

tolerance 1.0;

nSolveIter 30;

nRelaxIter 5;

nFeatureSnapIter 10;

implicitFeatureSnap false;

explicitFeatureSnap true;

multiRegionFeatureSnap false;
}

addLayersControls
{
{
/* Mesa
{
nSurfaceLayers 3;
} */
}

expansionRatio 1.1;

finalLayerThickness 0.2;

minThickness 0.1;

nGrow 0;


featureAngle 60;

slipFeatureAngle 30;

nRelaxIter 3;

nSmoothSurfaceNormals 1;

nSmoothNormals 3;

nSmoothThickness 10;

maxFaceThicknessRatio 0.5;

maxThicknessToMedialRatio 0.3;

minMedianAxisAngle 90;

nBufferCellsNoExtrude 0;

nLayerIter 50;
}


meshQualityControls
{

maxNonOrtho 45;

maxBoundarySkewness 20;

maxInternalSkewness 4;


maxConcave 80;


minVol 1e-13;


minTetQuality 1e-30;


minArea -1;

minTwist 0.01;

minDeterminant 0.001;

minFaceWeight 0.05;

minVolRatio 0.01;

minTriangleTwist -1;

nSmoothScale 4;

errorReduction 0.75;
}

writeFlags
(
scalarLevels
layerSets
layerFields
);


mergeTolerance 1e-6;