[tale_aasland]

Hi everyone,


I'm just getting started with openFoam, and currently, I'm trying to sort out snappyhexmesh, in order to mesh a 3D cylinder. The issue is that snappyhexmesh does not seem to do anything, although there are no actual error messages. The geometry is an stl file in ascii format. Blockmesh works, and the stl is placed within the background mesh (I checked using paraview), but no refinement occurs. The log says things like:


Marked for refinement due to explicit features : 0 cells.
Determined cells to refine in = 2.40163 s
Selected for feature refinement : 0 cells (out of 225000)
Stopping refining since too few cells selected.


I would very much appreciate some feedback on this. Here's my snappyhex dict file:


/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 12
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
object snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


castellatedMesh true;
snap true;
addLayers false;

geometry
{
cylinder
{
type triSurfaceMesh;
file "cylinder.stl";
}

};

castellatedMeshControls
{
maxLocalCells 100000;
maxGlobalCells 2000000;
minRefinementCells 0;
nCellsBetweenLevels 1;

features
(
{
file "cylinder.eMesh";
level 0;
}
);


refinmentSurfaces
{
cylinder
{
level (3 3);
}

}


resolveFeatureAngle 30;

allowFreeStandingZoneFaces true;
insidePoint (-5 -2 0);
};


snapControls
{
nSmoothPatch 3;
tolerance 1;
nSolveIter 100;
nRelaxIter 5;

// Feature snapping
nFeatureSnapIter 10;
implicitFeatureSnap false;
explicitFeatureSnap true;
multiRegionFeatureSnap true;
};

meshQualityControls
{
maxNonOrtho 75;
maxBoundarySkewness 20;
maxInternalSkewness 4;
maxConcave 80;

minVol 1.00E-13;
minTetQuality 1e15;

minArea -1;
minTwist 0.02;
minDeterminant 0.001;
minFaceWeight 0.05;
minVolRatio 0.01;
minTriangleTwist -1;
minFlatness 0.5;
nSmoothScale 4;

errorReduction 0.75;
};

mergeTolerance 1e-6;

[AtoHM]

An image might help.

Does your cylinder contain at least one cell of the background mesh (blockMesh) completely? Give the eMesh of the cylinder level 3 as well, that might help, too.


I see you have a typo in "refinmentSurfaces" - did that not give you an error message?

[tale_aasland]

Hi,


Thanks for your quick reply. The problem was the typo. It did not give an error message, strangely, but apparently it caused refinement commands to be disregarded.



Thank you so much!


Tale