CFD Online Discussion Forums - [snappyHexMesh] variables in snappyHexMeshDict

https://www.linkedin.com/grp/post/19...s-post-b-title

you're welcome. here it follows a template of mine I generally use to prepare the mesh. As posted before, I'm not mastering all variables.
Code:
FoamFile

{

    version     2.0;

    format      ascii;

    class       dictionary;

    object      snappyHexMeshDict;

}

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



// Which of the steps to run

castellatedMesh false;   // make basic mesh ?

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

addLayers       true;   // decide to add viscous layers ?





geometry // Load in STL files here

{

    amiRot1.stl {type triSurfaceMesh; name amiRot1;}

    amiRot2.stl {type triSurfaceMesh; name amiRot2;}

    amiRot3.stl {type triSurfaceMesh; name amiRot3;}

    wallStat.stl {type triSurfaceMesh; name wallStat;}    

    blade.stl {type triSurfaceMesh; name blade;}

    bladeInf.stl {type triSurfaceMesh; name bladeInf;}

    bladeTop.stl {type triSurfaceMesh; name bladeTop;}

    boccInf.stl {type triSurfaceMesh; name boccInf;}

    boccSup.stl {type triSurfaceMesh; name boccSup;}

    fanHub.stl {type triSurfaceMesh; name fanHub;}



    



};



castellatedMeshControls

{

    maxLocalCells 2000000;  //max cells per CPU core

    maxGlobalCells 4000000; //max cells to use before mesh deletion step

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

    maxLoadUnbalance 0.05;  //0.1 default

    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 "amiRot1.eMesh"; level 1;} 

        {file "amiRot2.eMesh"; level 1;}

        {file "amiRot3.eMesh"; level 1;}

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

        {file "blade.eMesh"; level 2;}

        {file "bladeInf.eMesh"; level 2;}

        {file "bladeTop.eMesh"; level 2;}

        {file "boccInf.eMesh"; level 2;}

        {file "boccSup.eMesh"; level 2;}

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

    

                        

    );



    // Surface based refinement

    // ~~~~~~~~~~~~~~~~~~~~~~~~



    refinementSurfaces // Surface-wise min and max refinement level

    {

    amiRot1 {level (2 2);}

        amiRot2 {level (2 2);}

    amiRot3 {level (2 2);} 

    wallStat {level (1 2);} //(2 2 )

    blade {level (2 2 );} 

    bladeInf {level (3 3);} 

    bladeTop {level (2 2);}

    boccInf {level (1 1 );} 

    boccSup {level (3 3);} 

    fanHub {level (2 2);} 

    

    

    }  





    resolveFeatureAngle 80;  //was80 Resolve sharp angles // Default 30

    refinementRegions       // In descending levels of fine-ness

    {

    //refine1 {mode inside; levels ((3 4));}



    } 



    locationInMesh (0 0 0.167);  //to decide which side of mesh to keep **

    allowFreeStandingZoneFaces false; //true;

}





// Settings for the snapping.

snapControls

{

    nSmoothPatch 0;// era 3;

    tolerance 2.0; //era 3.0 default is 2

    nSolveIter 250; //era30

    nRelaxIter 5; // efault 5

    nFeatureSnapIter 30; // default is 10

    

// 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; // deafault is false - detects features between multiple surfaces



}







// Settings for the layer addition.

addLayersControls //add the PATCH names from inside the STL file so STLpatchName_insideSTLName 

{

    relativeSizes false; // was true con false hanno la stessa grandezza

    layers

    {



    blade  {nSurfaceLayers 1;expansionRatio 1.12;firstLayerThickness 0.002;minThickness 0.00005;}

    bladeTop  {nSurfaceLayers 1;expansionRatio 1.12;firstLayerThickness 0.001;minThickness 0.00005;}

    bladeInf  {nSurfaceLayers 1;expansionRatio 1.12;firstLayerThickness 0.001;minThickness 0.00005;}

    fanHub {nSurfaceLayers 1;expansionRatio 1.12;firstLayerThickness 0.0022;minThickness 0.0001;}

    boccInf  {nSurfaceLayers 1;expansionRatio 1.12;firstLayerThickness 0.002;minThickness 0.00005;}

    

        

    }



    expansionRatio 1.12;

    //thickness 0.002;

    firstLayerThickness 0.002; //was 0.00018

    minThickness 0.00001;

    nGrow 0; // was 1 





    // Advanced settings



    // Static analysis of starting mesh



    featureAngle 310; //- When not to extrude surface. 0 is flat, 90 is right angle.

    nRelaxIter 5; //era 13 //- Max# of snapping relaxation iter. Should stop before upon reaching a correct mesh.

    maxFaceThicknessRatio 0.8; // Stop layer growth on highly warped cells



    // Patch displacement



    nSmoothSurfaceNormals 150;  //100 Number of smoothing iterations of surface normals

    nSmoothThickness 50;  //100 Smooth layer thickness over surface patches



    // Medial axis analysis    



    minMedianAxisAngle 135;  //135 Angle used to pick up medial axis points

    maxThicknessToMedialRatio 0.9; // Reduce layer growth where ratio thickness to medial distance is large

    nSmoothNormals 50; // Number of smoothing iterations of interior mesh movement direction

    

        // Optional: 

    //nMedialAxisIter 10;   //limit the number of steps walking away from the surface. Default is unlimited.

    //nSmoothDisplacement 90; //smooth displacement after medial axis determination. default is 0.

        // (wip)Optional: 

    //detectExtrusionIsland true;   // do not extrude a point if none of the surrounding points is not extruded. Default is false.



    // Mesh shrinking

    slipFeatureAngle 30; //at non-patched sides allow mesh to slip if extrusion direction makes angle larger than slipFeatureAngle. Default

             //is 0.5*featureAngle.

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

    nLayerIter 50; //Overall max number of layer addition iterations. The mesher will exit if it reaches this number of iterations;

           //possiblywith an illegal mesh.

    nRelaxedIter 0; // Max number of iterations after which relaxed meshQuality controls get used. Up to nRelaxedIter it uses the settings

             // in meshQualityControls, after nRelaxedIter it uses the values in meshQualityControls::relaxed.

            //IMPOSTANDOLO A 0 SHM UTILIZZA IMMEDIATAMENTE I VALORI RELAXED

  

        // Additional reporting: if there are just a few faces where there

        // are mesh errors (after adding the layers) print their face centres.

        // This helps in tracking down problematic mesh areas.

        //additionalReporting true;

}







// Generic mesh quality settings. At any undoable phase these determine

// where to undo.

meshQualityControls

{

   /* disabling mesh quality

  

  MaxNonOrtho 180;

  maxBoundarySkewness -1; 

  maxInternalSkewness -1;

  maxConcave 180;

  minVol -1e33;

  minTetQuality -1e30; 

  minTwist -1e30;

  minDeterminant -1; 

  minFaceWeight -1;

  minVolRatio -1;

  minArea -1;

  minTriangleTwist -1;

  */

    

    maxNonOrtho 55; //default 65

    maxBoundarySkewness 20;   

    maxInternalSkewness 4;   

    maxConcave 60; //default 80;

    minVol 1e-13;

    minTetQuality -1e30; 

    minFlatness 0.5;

    minTetQuality 1e-9;

    minArea -1;

    minTwist 0.05;

    minDeterminant 0.001;

    minVolRatio 0.01;

    minFaceWeight 0.05;

    minTriangleTwist -1;

    nSmoothScale 4;

    errorReduction 0.75; 



    // Advanced

    relaxed // mesh Quality Controls for layer addiction phase

    {

    maxNonOrtho 69;

    //maxBoundarySkewness 25;

    //maxInternalSkewness 5;

    maxConcave 100;

    minTwist 0.02;

    minFaceWeight 0.02;

    minDeterminant 0.0001;

    } 

}



// Advanced



debug 0;





// Merge tolerance. Is fraction of overall bounding box of initial mesh.

// Note: the write tolerance needs to be higher than this.

mergeTolerance 1E-6;





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