Question about snappyHexMesh and cellZone generation in OpenFOAM v2012
- Post By jiaming liu
- 3 months ago
- Post Type Public
Hi contributors,I sincerely appreciate your team's efforts in making your work publicly available online—it has been immensely helpful for OpenFOAM users and developers alike. After reading your article (Node266 - CFD SUPPORT), I followed the provided instructions to configure OpenFOAM to generate a cellZone using snappyHexMesh.
Unfortunately, the attempt was unsuccessful. The number of cells in both the cellZone and faceZones files turned out to be zero, and checkMesh.log confirms this issue. When I check the result via paraFoam, I also find that net0 ~ net4 contain no mesh—they are empty. This is not only contrary to my expectations, but also differs from the result described in the article.
I am using OpenFOAM v2012, and the net0 section in my snappyHexMeshDict was set up following the example from your webpage.
I’ve uploaded the relevant case below. I would greatly appreciate any guidance.
--------------------------------------------------------------------------------------------------
snappyhexmeshdict:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2012 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
#include "../varsSettings" //Include global variables
castellatedMesh true;
snap true;
addLayers false;//true;
geometry
{
floater
{
type triSurfaceMesh;
file "DeepCwindPlatform_heave.stl";
}
net1
{
type triSurfaceMesh;
file "Net1_improved_heave.stl";
}
net2
{
type triSurfaceMesh;
file "Net2_improved_heave.stl";
}
net3
{
type triSurfaceMesh;
file "Net3_improved_heave.stl";
}
net4
{
type triSurfaceMesh;
file "Net4_improved_heave.stl";
}
net0
{
type searchableBox;
min (-100 -50 -120);
max (100 50 -80);
}
refineFreeSurface_L1
{
type searchableBox;
min ($minX $minY -10);
max ($maxX $maxY 10);
}
refineFreeSurface_L2
{
type searchableBox;
min (#calc "$minX+$inLen+20" -70 -8);
max (#calc "$maxX-$outLen-20" 70 8);
}
refineFloater_L1
{
type searchableBox;
min (-51 -49 #calc "-30 + $decay_z + $offset_z");
max ( 37 49 #calc "22 + $decay_z + $offset_z");
}
};
castellatedMeshControls
{
maxLocalCells 100000;
maxGlobalCells 2000000;
minRefinementCells 0;
maxLoadUnbalance 0.10;
nCellsBetweenLevels 1;
features
(
{
file "DeepCwindPlatform_heave.eMesh";
level 4;
}
{
file "Net1_improved_heave.eMesh";
level 4;
}
{
file "Net2_improved_heave.eMesh";
level 4;
}
{
file "Net3_improved_heave.eMesh";
level 4; }
{
file "Net4_improved_heave.eMesh";
level 4;
}
);
refinementSurfaces
{
floater
{
level (4 4);//(5 5);
patchInfo
{
type wall;
// Optional group
// inGroups (meshedWalls);
}
}
net1
{
level (4 4);
cellZone net1Zone;
/* cellZoneInside inside;*/
faceZones net1fZone;
}
net2
{
level (4 4);
cellZone net2Zone;
/* cellZoneInside inside;*/
faceZones net2fZone;
}
net3
{
level (4 4);
cellZone net3Zone;
/* cellZoneInside inside;*/
faceZones net3fZone;
}
net4
{
level (4 4);
cellZone net4Zone;
/* cellZoneInside inside;*/
faceZones net4fZone;
}
net0
{
level (4 4);
cellZone net0Zone;
/* cellZoneInside inside;*/
faceZones net0fZone;
}
}
resolveFeatureAngle 45;//30;
planarAngle 30;
refinementRegions
{
refineFreeSurface_L1
{
mode inside;
levels ((1e-5 1)); //First entry here is distance, which will be ignored unless mode = distance
}
refineFreeSurface_L2
{
mode inside;
levels ((1e-5 2)); //First entry here is distance, which will be ignored unless mode = distance
}
refineFloater_L1
{
mode inside;
levels ((1e-5 2)); //First entry here is distance, which will be ignored unless mode = distance
}
/* net1*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3)); // STL 内部 refinement 到 level 4*/
/* }*/
/* net2*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3));*/
/* }*/
/* net3*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3));*/
/* }*/
/* net4*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3));*/
/* }*/
}
limitRegions
{
}
locationInMesh (-150 0 0);
allowFreeStandingZoneFaces true;//false;
faceZoneControls
{
}
locationsOutsideMesh ((100 100 100));
}
snapControls
{
nSmoothPatch 5;//3
tolerance 2.0;
nSolveIter 50;//30;
nRelaxIter 10;//5;
nFeatureSnapIter 20;//10;
implicitFeatureSnap false;//true;
explicitFeatureSnap true;//false;
multiRegionFeatureSnap false;
}
addLayersControls
{
relativeSizes true;
expansionRatio 1.25;
finalLayerThickness 0.64;
minThickness 0.1;
layers
{
floater
{
nSurfaceLayers 2;//3;
}
}
nGrow 0;
featureAngle 180;//180;
maxFaceThicknessRatio 0.5;//0.5;
nSmoothSurfaceNormals 1;
nSmoothThickness 10;
minMedialAxisAngle 90;
maxThicknessToMedialRatio 0.3;
nSmoothNormals 3;
slipFeatureAngle 30;
nRelaxIter 5;
nBufferCellsNoExtrude 0;
nLayerIter 50;
nRelaxedIter 20;
}
meshQualityControls
{
#include "meshQualityDict"
relaxed
{
maxNonOrtho 75;
}
nSmoothScale 4;
errorReduction 0.75;
}
mergeTolerance 1e-6;
// ************************************************************************* //
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2012 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
#include "../varsSettings" //Include global variables
castellatedMesh true;
snap true;
addLayers false;//true;
geometry
{
floater
{
type triSurfaceMesh;
file "DeepCwindPlatform_heave.stl";
}
net1
{
type triSurfaceMesh;
file "Net1_improved_heave.stl";
}
net2
{
type triSurfaceMesh;
file "Net2_improved_heave.stl";
}
net3
{
type triSurfaceMesh;
file "Net3_improved_heave.stl";
}
net4
{
type triSurfaceMesh;
file "Net4_improved_heave.stl";
}
net0
{
type searchableBox;
min (-100 -50 -120);
max (100 50 -80);
}
refineFreeSurface_L1
{
type searchableBox;
min ($minX $minY -10);
max ($maxX $maxY 10);
}
refineFreeSurface_L2
{
type searchableBox;
min (#calc "$minX+$inLen+20" -70 -8);
max (#calc "$maxX-$outLen-20" 70 8);
}
refineFloater_L1
{
type searchableBox;
min (-51 -49 #calc "-30 + $decay_z + $offset_z");
max ( 37 49 #calc "22 + $decay_z + $offset_z");
}
};
castellatedMeshControls
{
maxLocalCells 100000;
maxGlobalCells 2000000;
minRefinementCells 0;
maxLoadUnbalance 0.10;
nCellsBetweenLevels 1;
features
(
{
file "DeepCwindPlatform_heave.eMesh";
level 4;
}
{
file "Net1_improved_heave.eMesh";
level 4;
}
{
file "Net2_improved_heave.eMesh";
level 4;
}
{
file "Net3_improved_heave.eMesh";
level 4; }{
file "Net4_improved_heave.eMesh";
level 4;
}
);
refinementSurfaces
{
floater
{
level (4 4);//(5 5);
patchInfo
{
type wall;
// Optional group
// inGroups (meshedWalls);
}
}
net1
{
level (4 4);
cellZone net1Zone;
/* cellZoneInside inside;*/
faceZones net1fZone;
}
net2
{
level (4 4);
cellZone net2Zone;
/* cellZoneInside inside;*/
faceZones net2fZone;
}
net3
{
level (4 4);
cellZone net3Zone;
/* cellZoneInside inside;*/
faceZones net3fZone;
}
net4
{
level (4 4);
cellZone net4Zone;
/* cellZoneInside inside;*/
faceZones net4fZone;
}
net0
{
level (4 4);
cellZone net0Zone;
/* cellZoneInside inside;*/
faceZones net0fZone;
}
}
resolveFeatureAngle 45;//30;
planarAngle 30;
refinementRegions
{
refineFreeSurface_L1
{
mode inside;
levels ((1e-5 1)); //First entry here is distance, which will be ignored unless mode = distance
}
refineFreeSurface_L2
{
mode inside;
levels ((1e-5 2)); //First entry here is distance, which will be ignored unless mode = distance
}
refineFloater_L1
{
mode inside;
levels ((1e-5 2)); //First entry here is distance, which will be ignored unless mode = distance
}
/* net1*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3)); // STL 内部 refinement 到 level 4*/
/* }*/
/* net2*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3));*/
/* }*/
/* net3*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3));*/
/* }*/
/* net4*/
/* {*/
/* mode inside;*/
/* levels ((1e-5 3));*/
/* }*/
}
limitRegions
{
}
locationInMesh (-150 0 0);
allowFreeStandingZoneFaces true;//false;
faceZoneControls
{
}
locationsOutsideMesh ((100 100 100));
}
snapControls
{
nSmoothPatch 5;//3
tolerance 2.0;
nSolveIter 50;//30;
nRelaxIter 10;//5;
nFeatureSnapIter 20;//10;
implicitFeatureSnap false;//true;
explicitFeatureSnap true;//false;
multiRegionFeatureSnap false;
}
addLayersControls
{
relativeSizes true;
expansionRatio 1.25;
finalLayerThickness 0.64;
minThickness 0.1;
layers
{
floater
{
nSurfaceLayers 2;//3;
}
}
nGrow 0;
featureAngle 180;//180;
maxFaceThicknessRatio 0.5;//0.5;
nSmoothSurfaceNormals 1;
nSmoothThickness 10;
minMedialAxisAngle 90;
maxThicknessToMedialRatio 0.3;
nSmoothNormals 3;
slipFeatureAngle 30;
nRelaxIter 5;
nBufferCellsNoExtrude 0;
nLayerIter 50;
nRelaxedIter 20;
}
meshQualityControls
{
#include "meshQualityDict"
relaxed
{
maxNonOrtho 75;
}
nSmoothScale 4;
errorReduction 0.75;
}
mergeTolerance 1e-6;
// ************************************************************************* //
Thank you very much in advance!
Best regards,
Liu Jiaming
