[t112a89403@ntut.org.tw]

I hope you are all fine and doing well. I have one issue with meshing and it is stated below.

I am meshing NACA0015 using snappyHexMeshDict, but the wall (edge) of the airfoil edge becomes deformed once the mesh is refined. I am not that much an expert in snappyHexMesh, so I am looking for your help. As well as my snappyHexMeshDict code, I have attached the image that came from Paraview.


Thank you!!!

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 8 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


castellatedMesh true;
snap true;
addLayers true;


geometry
{
wing
{
type triSurfaceMesh;
file "wing.obj";
}

refinementBox
{
type searchableBox;
min (-1 -1 -0.1875);
max ( 3.5 1 0.1875);
}
}

castellatedMeshControls
{
maxLocalCells 250000000;

maxGlobalCells 500000000;

minRefinementCells 0;

nCellsBetweenLevels 8;

maxLoadUnbalance 0.1;

features
( );

resolveFeatureAngle 60;

refinementSurfaces
{
wing
{
// Surface-wise min and max refinement level
level (6 8);
}
}

locationInMesh (1.25 0.5 0.025);

refinementRegions
{
refinementBox
{
mode inside;
levels ((1e15 2));
}
}

allowFreeStandingZoneFaces true;
}


snapControls
{
nSmoothPatch 3;

tolerance 2.0;

nSolveIter 100;

nRelaxIter 5;

//nFeatureSnapIter 5;
}


addLayersControls
{
relativeSizes false;

layers
{
wing
{
nSurfaceLayers 4;
}
}

expansionRatio 1.3;

finalLayerThickness 0.003125;

minThickness 0.00000001;

nGrow 0;

featureAngle 60;

nRelaxIter 5;

nSmoothSurfaceNormals 1;

nSmoothNormals 3;

nSmoothThickness 8;

maxFaceThicknessRatio 0.5;

maxThicknessToMedialRatio 0.3;

minMedianAxisAngle 90;

nBufferCellsNoExtrude 0;

nLayerIter 50;
}


meshQualityControls
{
maxNonOrtho 65;

maxBoundarySkewness 20;

maxInternalSkewness 4;

maxConcave 80;

minVol 1E-13;

minTetQuality 1E-30;

minArea 1E-13;

minTwist 0.05;

minDeterminant 0.001;

minFaceWeight 0.05;

minVolRatio 0.01;

minTriangleTwist -1;


//Advanced
nSmoothScale 4;

errorReduction 0.8;
}


//Advanced
debug 0;

mergeTolerance 1E-06;


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