/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v1912 | | \\ / A nd | Website: www.openfoam.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; object snappyHexMeshDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // // Which of the steps to run castellatedMesh true; snap false; addLayers false; // Geometry. Definition of all surfaces. All surfaces are of class // searchableSurface. // Surfaces are used // - to specify refinement for any mesh cell intersecting it // - to specify refinement for any mesh cell inside/outside/near // - to 'snap' the mesh boundary to the surface geometry { box1 //0.6x1x0.02 [cm] { type box; min (-0.1 -0.01 -0.1); max (0.1 0.30 0.1); } } // Settings for the castellatedMesh generation. castellatedMeshControls { // Refinement parameters // ~~~~~~~~~~~~~~~~~~~~~ // If local number of cells is >= maxLocalCells on any processor // switches from from refinement followed by balancing // (current method) to (weighted) balancing before refinement. maxLocalCells 1000000; // Overall cell limit (approximately). Refinement will stop immediately // upon reaching this number so a refinement level might not complete. // Note that this is the number of cells before removing the part which // is not 'visible' from the keepPoint. The final number of cells might // actually be a lot less. maxGlobalCells 2000000; // The surface refinement loop might spend lots of iterations refining just a // few cells. This setting will cause refinement to stop if <= minimumRefine // are selected for refinement. Note: it will at least do one iteration // (unless the number of cells to refine is 0) minRefinementCells 100; // Number of buffer layers between different levels. // 1 means normal 2:1 refinement restriction, larger means slower // refinement. nCellsBetweenLevels 1; // Region-wise refinement // ~~~~~~~~~~~~~~~~~~~~~~ // Specifies refinement level for cells in relation to a surface. One of // three modes // - distance. 'levels' specifies per distance to the surface the // wanted refinement level. The distances need to be specified in // descending order. // - inside. 'levels' is only one entry and only the level is used. All // cells inside the surface get refined up to the level. The surface // needs to be closed for this to be possible. // - outside. Same but cells outside. features ( ); resolveFeatureAngle 0; refinementSurfaces { } refinementRegions { box1 { mode inside; levels ((1.0 1)); } } // Mesh selection // ~~~~~~~~~~~~~~ // After refinement patches get added for all refinementSurfaces and // all cells intersecting the surfaces get put into these patches. The // section reachable from the locationInMesh is kept. // NOTE: This point should never be on a face, always inside a cell, even // after refinement. locationInMesh (0.01 0 0.001); // Whether any faceZones (as specified in the refinementSurfaces) // are only on the boundary of corresponding cellZones or also allow // free-standing zone faces. Not used if there are no faceZones. allowFreeStandingZoneFaces true; } // Settings for the snapping. snapControls { //- Number of patch smoothing iterations before finding correspondence // to surface nSmoothPatch 3; //- Relative distance for points to be attracted by surface feature point // or edge. True distance is this factor times local // maximum edge length. tolerance 4.0; //- Number of mesh displacement relaxation iterations. nSolveIter 30; //- Maximum number of snapping relaxation iterations. Should stop // before upon reaching a correct mesh. nRelaxIter 5; } // Settings for the layer addition. addLayersControls { // Are the thickness parameters below relative to the undistorted // size of the refined cell outside layer (true) or absolute sizes (false). relativeSizes false; // Layer thickness specification. This can be specified in one of following // ways: // - expansionRatio and finalLayerThickness (cell nearest internal mesh) // - expansionRatio and firstLayerThickness (cell on surface) // - overall thickness and firstLayerThickness // - overall thickness and finalLayerThickness // - overall thickness and expansionRatio // // Note: the mode thus selected is global, i.e. one cannot override the // mode on a per-patch basis (only the values can be overridden) // Expansion factor for layer mesh expansionRatio 1.0; // Wanted thickness of the layer furthest away from the wall. // If relativeSizes this is relative to undistorted size of cell // outside layer. finalLayerThickness 0.3; // Wanted thickness of the layer next to the wall. // If relativeSizes this is relative to undistorted size of cell // outside layer. //firstLayerThickness 0.3; // Wanted overall thickness of layers. // If relativeSizes this is relative to undistorted size of cell // outside layer. //thickness 0.5 // Minimum overall thickness of total layers. If for any reason layer // cannot be above minThickness do not add layer. // If relativeSizes this is relative to undistorted size of cell // outside layer.. minThickness 0.25; // Per final patch (so not geometry!) the layer information // Note: This behaviour changed after 21x. Any non-mentioned patches // now slide unless: // - nSurfaceLayers is explicitly mentioned to be 0. // - angle to nearest surface < slipFeatureAngle (see below) layers { } // If points get not extruded do nGrow layers of connected faces that are // also not grown. This helps convergence of the layer addition process // close to features. // Note: changed(corrected) w.r.t 1.7.x! (didn't do anything in 1.7.x) nGrow 0; // Static analysis of starting mesh // When not to extrude surface. 0 is flat surface, 90 is when two faces // are perpendicular featureAngle 130; // Stop layer growth on highly warped cells maxFaceThicknessRatio 0.5; // Patch displacement // Number of smoothing iterations of surface normals nSmoothSurfaceNormals 1; // Smooth layer thickness over surface patches nSmoothThickness 10; // Mesh shrinking // Optional: at non-patched sides allow mesh to slip if extrusion // direction makes angle larger than slipFeatureAngle. Default is // 0.5*featureAngle. slipFeatureAngle 30; // Maximum number of snapping relaxation iterations. Should stop // before upon reaching a correct mesh. nRelaxIter 5; // Create buffer region for new layer terminations nBufferCellsNoExtrude 0; // Overall max number of layer addition iterations. The mesher will // exit if it reaches this number of iterations; possibly with an // illegal mesh. nLayerIter 50; // 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. nRelaxedIter 20; // 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 { //- Maximum non-orthogonality allowed. Set to 180 to disable. maxNonOrtho 65; //- Max skewness allowed. Set to <0 to disable. maxBoundarySkewness 20; maxInternalSkewness 4; //- Max concaveness allowed. Is angle (in degrees) below which concavity // is allowed. 0 is straight face, <0 would be convex face. // Set to 180 to disable. maxConcave 80; //- Minimum pyramid volume. Is absolute volume of cell pyramid. // Set to a sensible fraction of the smallest cell volume expected. // Set to very negative number (e.g. -1E30) to disable. minVol 1e-13; //- Minimum tet volume. Is absolute volume of the tet formed by the // face-centre decomposition triangle and the cell centre. // Set to a sensible fraction of the smallest cell volume expected. // Set to very negative number (e.g. -1E30) to disable. minTetVol 1e-20; minTetQuality -1; //- Minimum face area. Set to <0 to disable. minArea -1; //- Minimum face twist. Set to <-1 to disable. dot product of face normal //- and face centre triangles normal minTwist 0.05; //- minimum normalised cell determinant //- 1 = hex, <= 0 = folded or flattened illegal cell // minDeterminant 0.001; minDeterminant 1; //- minFaceWeight (0 -> 0.5) minFaceWeight 0.05; //- minVolRatio (0 -> 1) minVolRatio 0.01; //must be >0 for Fluent compatibility minTriangleTwist -1; // Advanced //- Number of error distribution iterations nSmoothScale 4; //- amount to scale back displacement at error points errorReduction 0.75; } // Advanced // Flags for optional output // 0 : only write final meshes // 1 : write intermediate meshes // 2 : write volScalarField with cellLevel for postprocessing // 4 : write current intersections as .obj files 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; // ************************************************************************* //