CFD Online Discussion Forums - [snappyHexMesh] Problem creating patches using snappyheymesh

i add my snappyHexMeshDict:
Code:
/*--------------------------------*- C++ -*----------------------------------*\

| =========                 |                                                 |

| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |

|  \\    /   O peration     | Version:  2.2.0                                 |

|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |

|    \\/     M anipulation  |                                                 |

\*---------------------------------------------------------------------------*/

FoamFile

{

    version     2.0;

    format      ascii;

    class       dictionary;

    object      snappyHexMeshDict;

}

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



// Which of the steps to run; true/false to switch on/off

castellatedMesh true;   // make basic mesh?

snap            true;   // decide to snap back to surface?

addLayers       false;   // decide to add viscous layers?









geometry        //Load in STL files here and define patch names; refinement areas possible

{

    rotor.stl 

        {

            type triSurfaceMesh;        //The standard type “triSurfaceMesh” reads a copy of each surface on to each processor when running in parallel.

            name rotor;                 //defines the patch name for further use in the file

        } 

    ader.stl 

        {

            type triSurfaceMesh; 

            name ader;

        }

    stator_hohl.stl 

        {

            type triSurfaceMesh; 

            name stator_hohl;

        }

}









castellatedMeshControls         //Prescribe feature, surface and volume mesh refinements

{

    maxLocalCells 1000000;      //max cells per CPU core

    maxGlobalCells 2000000;     //max cells to use before mesh deletion step

    minRefinementCells 10;      //was 0 - zero means no bad cells are allowed during refinement stages

    maxLoadUnbalance 0.10;

    nCellsBetweenLevels 1;      // expansion factor between each high & low refinement zone



    //Explicit feature edge refinement

    features                    //taken from STL from each .eMesh file created by "SurfaceFeatureExtract" command

    (

        {file "rotor.eMesh"; level 1;} 

        {file "stator_hohl.eMesh"; level 1;}

        {file "ader.eMesh"; level 1;}

    );



    //Surface based refinement

    refinementSurfaces          //Surface-wise min and max refinement level

    {

    rotor {level (2 2);}

    stator_hohl {level (2 2);}

    ader {level (0 0);}

    }  



    resolveFeatureAngle 80;     //Resolve sharp angles; Default 30



    refinementRegions           //In descending levels of fine-ness

    {

        ader

        {

            mode distance;      //mode distance means 0.0006 meters from surface it will refine to level 4; others possible: "inside", "outside"

            levels ((0.001 1)); 

        }

    } 

    

    locationInMesh (-0.0028 -0.0050 0.0035);    //to decide which side of mesh to keep; very very important; pick a point in paraView inside the area you want to be meshed; vor rotor: (-0.0028 -0.0050 0.0035); innerhalb stator: (0.01 0.01 -0.007) 

    allowFreeStandingZoneFaces true;           //Whether to allow zone faces that share the same owner and neighbour cell zone. If kept these can cause quality issues when the zone faces are snapped to the surface

}









snapControls                    //Settings for the snapping; Control mesh surface snapping

{

    nSmoothPatch 3;             //Number of pre smoothing iterations of patch points before projection to the surface is performed

    tolerance 4.0;              //Scaling of the maximum edge length for attraction to the surface

    nSolveIter 30;              //Number of interior smoothing iterations applied to snapped displacement field

    nRelaxIter 5;               //Controls number of scaling back iterations for error reduction stage

    nFeatureSnapIter 15;        //default is 10; Number of feature snapping iterations to perform.

    

    // New settings from openfoam 2.2 onwards for SHMesh

    implicitFeatureSnap false;          //default is false - detects without doing surfaceFeatureExtract

    explicitFeatureSnap true;           //default is true

    multiRegionFeatureSnap false;       //default is false - detects features between multiple surfaces

}









addLayersControls                       //Control boundary layer mesh growth. Add the PATCH names from inside the STL file so STLpatchName_insideSTLName 

{

    layers

    {

    rotor

             {nSurfaceLayers 1;}     //Specification of the number of layers to be grown on each patch.

    }



    expansionRatio 1.3;                 //expansionRatio is the ratio of heights from one layer to the next consecutive layer in the direction away from the surface

    finalLayerThickness 0.00016;        //finalLayerThickness is the ratio of the final layer height relative to the adjacent surface mesh size

    minThickness 0.00008;               //Specification of a minimum layer thickness below which height layers will automatically be collapsed. 

    relativeSizes false;                //The final layer thickness and minimum thickness can be defined as either being relative (true) to the background spacing ΔS or defined as an absolute (false) length

    nGrow 0;                            //was 1 



    // Advanced settings

    featureAngle 80;                    //When not to extrude surface. 0 is flat, 90 is right angle.

    

    nRelaxIter 5;                       //Max# of snapping relaxation iter. Should stop before upon reaching a correct mesh.

    

    nSmoothSurfaceNormals 1;            //Number of smoothing iterations of surface normals; default=1

    nSmoothNormals 3;                   //Number of smoothing iterations of interior mesh movement direction; default=3

    nSmoothThickness 10;                //Smooth layer thickness over surface patches; default=10

    

    maxThicknessToMedialRatio 0.3;      //Reduce layer growth where ratio thickness to medial distance is large;  default=0.3

    minMedianAxisAngle 130;             //Angle used to pick up medial axis points

    

    maxFaceThicknessRatio 0.5;          //Stop layer growth on highly warped cells

    

    nBufferCellsNoExtrude 0;            //Create buffer region for new layer terminations

    

    nLayerIter 50;                      //Overall max number of layer addition iterations

}









meshQualityControls             //Generic mesh quality settings. At any undoable phase these determine where to undo.

{

    maxNonOrtho 65;             //default=65

    maxBoundarySkewness 20;     //default=20

    maxInternalSkewness 4;      //default=4

    maxConcave 80;              //default=80

    minFlatness 0.5; 

    minVol 1e-13;               //default=1e-13

    minTetQuality 1e-9;         //This metric needs to be set to a small positive value to guarantee an inside cell check works correctly for tracking routines e.g. streamlines 

    minArea -1e-13;             //default=1e-30

    minTwist 0.02;              //default=0.05

    minDeterminant 0.001;       //default=0.001

    minFaceWeight 0.02;         //default=0.05

    minVolRatio 0.01;           //default=0.01

    minTriangleTwist -1;        //default=-1



    // Advanced

    nSmoothScale 4;             //default=4

    errorReduction 0.75;        //default=0.75

}









// Advanced



debug 0;                //put to "1" if all meshes should be written, not only the final one



mergeTolerance 1E-6;    // Merge tolerance. Is fraction of overall bounding box of initial mesh. Note: the write tolerance needs to be higher than this.





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