jiaming liu

• 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;
// ************************************************************************* //

Thank you very much in advance!

Best regards,

Liu Jiaming