/*--------------------------------*- 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; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // // Which of the steps to run castellatedMesh true; snap true; addLayers false; // Optional: single region surfaces get patch names according to // surface only. Multi-region surfaces get patch name // surface "_ "region. Default is true // singleRegionName false; // Optional: avoid patch-face merging. Allows mesh to be used for // refinement/unrefinement // mergePatchFaces false; // default true // Optional: preserve all generated patches. Default is to remove // zero-sized patches. // keepPatches true; // 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 { box1x1x1 { type searchableBox; min (1.5 1 -0.5); max (3.5 2 0.5); } // Shell for directional refinement wakeBox { type searchableBox; min (1.5 1 -0.5); max (3.5 2 0.5); } sphere.stl { type triSurfaceMesh; //tolerance 1E-5; // optional:non-default tolerance on intersections //maxTreeDepth 10; // optional:depth of octree. Decrease only in case // of memory limitations. // Per region the patchname. If not provided will be _. // Note: this name cannot be used to identity this region in any // other part of this dictionary; it is only a name // for the combination of surface+region (which is only used // when creating patches) regions { secondSolid { name mySecondPatch; } } } sphere2 { type searchableSphere; centre (1.5 1.5 1.5); radius 1.03; } }; // 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 100000; // 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 // <= minRefinementCells cells are selected for refinement. Note: it will // at least do one iteration unless // a: the number of cells to refine is 0 // b: minRefinementCells = -1. This is a special value indicating // no refinement. minRefinementCells 0; // Allow a certain level of imbalance during refining // (since balancing is quite expensive) // Expressed as fraction of perfect balance (= overall number of cells / // nProcs). 0=balance always. maxLoadUnbalance 0.10; // Number of buffer layers between different levels. // 1 means normal 2:1 refinement restriction, larger means slower // refinement. nCellsBetweenLevels 1; // Explicit feature edge refinement // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // Specifies a level for any cell intersected by explicitly provided // edges. // This is a featureEdgeMesh, read from constant/triSurface for now. // Specify 'levels' in the same way as the 'distance' mode in the // refinementRegions (see below). The old specification // level 2; // is equivalent to // levels ((0 2)); features ( //{ // file "someLine.eMesh"; // //level 2; // Have level 2 for all cells intersected // // by feature. // levels ((0.1 2)); // Have level 2 for all cells within // // 0.1 of feature. //} ); // Surface based refinement // ~~~~~~~~~~~~~~~~~~~~~~~~ // Specifies two levels for every surface. The first is the minimum level, // every cell intersecting a surface gets refined up to the minimum level. // The second level is the maximum level. Cells that 'see' multiple // intersections where the intersections make an // angle > resolveFeatureAngle get refined up to the maximum level. refinementSurfaces { sphere.stl { // Surface-wise min and max refinement level level (2 2); // Optional region-wise level specification regions { secondSolid { level (3 3); } } // Optional specification of patch type (default is wall). No // constraint types (cyclic, symmetry) etc. are allowed. patchInfo { type patch; inGroups (meshedPatches); } //- Optional increment (on top of max level) in small gaps //gapLevelIncrement 2; //- Optional angle to detect small-large cell situation // perpendicular to the surface. Is the angle of face w.r.t. // the local surface normal. Use on flat(ish) surfaces only. // Otherwise leave out or set to negative number. //perpendicularAngle 10; //- Optional faceZone and (for closed surface) cellZone with // how to select the cells that are in the cellZone // (inside / outside / specified insidePoint) // The orientation of the faceZone is // - if on cellZone(s) : point out of (minimum) cellZone // - if freestanding : oriented according to surface //faceZone sphere; //cellZone sphere; //cellZoneInside inside; // outside/insidePoint //insidePoint (1 1 1); // if (cellZoneInside == insidePoint) //- Optional specification of what to do with faceZone faces: // internal : keep them as internal faces (default) // baffle : create baffles from them. This gives more // freedom in mesh motion // boundary : create free-standing boundary faces (baffles // but without the shared points) //faceType baffle; } } // Feature angle: // - used if min and max refinement level of a surface differ // - used if feature snapping (see snapControls below) is used resolveFeatureAngle 30; //- Optional increment (on top of max level) in small gaps //gapLevelIncrement 2; // Planar angle: // - used to determine if surface normals // are roughly the same or opposite. Used // - in proximity refinement // - to decide when to merge free-standing baffles // (if e.g. running in surfaceSimplify mode set this to 180 to // merge all baffles) // - in snapping to avoid snapping to nearest on 'wrong' side // of thin gap // // If not specified same as resolveFeatureAngle planarAngle 30; // 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 // increasing 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. refinementRegions { box1x1x1 { mode inside; levels ((1.0 4)); } //sphere.stl //{ // mode inside; // levels ((1.0 4)); // // Optional override of uniform refinement level such // // that in small gaps we're getting more cells. // // The specification is // // - numGapCells : minimum number of cells in the gap // // (usually >3; lower than this might not // // resolve correctly) // // - minLevel : min refinement level at which to kick in // // - maxLevel : upper refinement level (to avoid refinement // // continuing on a single extraneous feature) // // All three settings can be overridden on a surface by // // surface basis in the refinementSurfaces section. // gapLevel ( ); // // Optional: when doing the gapLevel refinement directly remove // // based on orientation w.r.t. gap. This limits the // // amount of cells before doing the 'locationInMesh' // // cell selection. Default is 'mixed' i.e. keep cells // // whilst doing the gap-level refinement. // //gapMode inside; // inside/outside/mixed // //gapSelf false; // ignore gaps in same surface //} //wakeBox //{ // mode inside; // // Dummy base level // levels ((10000 0)); // // // Optional directional refinement (after all other refinement) // // Directional refinement // // for all cells according to 'mode' ('inside' or 'outside'; // // 'distance' not supported) and within certain range. E.g. // // - for all cells with level 2-5 // // - do one split in x direction // levelIncrement (2 5 (1 0 0)); // // // Note // // - ignores 'levels' and gap* settings. // // - the cellLevel/pointLevels files are no longer consistent // // with the mesh, the resulting mesh is no longer compatible // // with e.g. dynamic refinement/unrefinement. // // - cellLevel will include any directional refinement // // (i.e. it will be the maximum of all three directions) //} //wakeBox //{ // mode inside; // // Dummy base level // levels ((10000 0)); // // // Optional directional refinement (after all other refinement) // // Directional refinement // // for all cells according to 'mode' ('inside' or 'outside'; // // 'distance' not supported) and within certain range. E.g. // // - for all cells with level 2-5 // // - do one split in x direction // levelIncrement (2 5 (1 0 0)); // // // Note // // - ignores 'levels' and gap* settings. // // - the cellLevel/pointLevels files are no longer consistent // // with the mesh, the resulting mesh is no longer compatible // // with e.g. dynamic refinement/unrefinement. // // - cellLevel will include any directional refinement // // (i.e. it will be the maximum of all three directions) // // // Optional directional expansion-ratio smoothing (after all // // refinement). This will try to smooth out edge/cell size jumps // // Specify smoothing direction and number of iterations // smoothDirection (1 0 0); // // Smoothing of expansion ratio // nSmoothExpansion 100; // // Smoothing of positions // nSmoothPosition 100; //} } // Optionally limit refinement in geometric region. This limits all // refinement (from features, refinementSurfaces, refinementRegions) // in a given geometric region. The syntax is exactly the same as for the // refinementRegions; the cell level now specifies the upper limit // for any cell. (a special setting is cell level -1 which will remove // any cells inside the region). Note that it does not override the // refinement constraints given by the nCellsBetweenLevels setting. limitRegions { } // 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 location(s)InMesh is kept. // NOTE: This point should never be on a face, always inside a cell, even // after refinement. // // There are two different ways of specifying the regions to keep: // 1. a single locationInMesh. This is the unzoned part of the mesh. // All the 'zoned' surfaces are marked as such // in the refinementSurfaces with the faceZone and cellZone keywords. // It is illegal to have the locationInMesh inside a surface for which // a cellZone is specified. // // or // // 2. multiple locationsInMesh, with per location the name of the cellZone. // This uses walking to determine zones and automatically creates // faceZones on the outside of cellZones. The special name 'none' is // used to indicate the unzoned/background part of the mesh. // Ad 1. Specify a single location and how to treat faces inbetween // cellZones locationInMesh (5 0.28 0.43); // Whether any faceZones (as specified in the refinementSurfaces) // are only on the boundary of corresponding cellZones. // Not used if there are no faceZones. The behaviour has changed // with respect to previous versions: // true : all intersections with surface are put in faceZone // (same behaviour as before) // false : depending on the type of surface intersected: // - if intersecting surface has faceZone only (so no cellZone) // leave in faceZone (so behave as if set to true) (= changed // behaviour) // - if intersecting surface has faceZone and cellZone // remove if inbetween same cellZone or if on boundary // (same behaviour as before) allowFreeStandingZoneFaces true; // 2. Specify multiple locations with optional cellZones for the // regions (use cellZone "none" to specify the unzoned cells) // FaceZones are automatically constructed from the // names of the cellZones: _to_ // where the cellZoneA is the lowest numbered cellZone (non-cellZone // cells are in a special region called "none" which is always // last). locationsInMesh ( ((-0.09 -0.039 -0.049) bottomAir) // cellZone 0 ((-0.09 0.009 -0.049) topAir) // cellZone 1 ((-0.09 0.001 -0.049) leftSolid) // cellZone 2 ((0.02 0.001 -0.049) rightSolid) // cellZone 3 ((-0.001 -0.039 0.0015) heater) // cellZone 4 ); // Per synthesised faceZone name the faceType and type of baffles to // create faceZoneControls { bottomAir_to_heater { // Optional specification of patch type (default is wall). No // constraint types (cyclic, symmetry) etc. are allowed. patchInfo { type patch; inGroups (patchPatches); } faceType baffle; } } // Optional locations that should not be reachable from // location(s)InMesh locationsOutsideMesh ((100 100 100)); // Optional: do not remove cells likely to give snapping problems // handleSnapProblems false; // Optional: switch off topological test for cells to-be-squashed // and use geometric test instead //useTopologicalSnapDetection false; // Optional: do not refine surface cells with opposite faces of // differing refinement levels //interfaceRefine false; // Optional: use an erosion instead of region assignment to allocate // left-over cells to the background region (i.e. make cellZones // consistent with the intersections of the surface). // Erosion is specified as a number of erosion iterations. // Erosion has less chance of bleeding and changing the zone // for a complete region. // A negative value implements 'growing' the cellZones which // might help with small non-physical gaps inbetween cellZones. // (currently only a single layer growth i.e. -1 is supported) // Default value is 0. //nCellZoneErodeIter 2; // Optional: delete any region smaller than below fraction of the overall // size (on a per-zone basis). This is occasionally useful // when generating meshes with faceZones as baffles or boundary // faces. //minCellFraction 0.001; } // Settings for the snapping. snapControls { // Number of patch smoothing iterations before finding correspondence // to surface nSmoothPatch 3; // Optional: number of smoothing iterations for internal points on // refinement interfaces. This will reduce non-orthogonality on // refinement interfaces. //nSmoothInternal $nSmoothPatch; // Maximum relative distance for points to be attracted by surface. // True distance is this factor times local maximum edge length. tolerance 2.0; // Number of mesh displacement relaxation iterations. nSolveIter 30; // Maximum number of snapping relaxation iterations. Should stop // before upon reaching a correct mesh. nRelaxIter 5; // (wip) disable snapping to opposite near surfaces (revert to 22x // behaviour) // detectNearSurfacesSnap false; // Feature snapping // Number of feature edge snapping iterations. // Leave out altogether to disable. nFeatureSnapIter 10; // Detect (geometric only) features by sampling the surface // (default=false). implicitFeatureSnap false; // Use castellatedMeshControls::features (default = true) explicitFeatureSnap true; // Detect features between multiple surfaces // (only for explicitFeatureSnap, default = false) multiRegionFeatureSnap false; //- When to run face splitting (never at first iteration, always // at last iteration). Is interval. Default -1 (disabled) //nFaceSplitInterval 5; // (wip) Optional for explicit feature snapping: //- Detect baffle edges. Default is true. //detectBaffles false; //- On any faces where points are on multiple regions (see // multiRegionFeatureSnap) have the other points follow these points // instead of having their own independent movement, i.e. have snapping // to multi-region edges/points take priority. This might aid snapping // to sharp edges that are also region edges. The default is false. //releasePoints true; //- Walk along feature edges, adding missing ones. Default is true. //stringFeatures false; //- If diagonal attraction also attract other face points. Default is // false //avoidDiagonal true; //- When splitting what concave faces to leave intact. Default is 45 // degrees. //concaveAngle 30; //- When splitting the minimum area ratio of faces. If face split // causes ratio of area less than this do not split. Default is 0.3 //minAreaRatio 0.3; //- Attract points only to the surface they originate from. Default // false. This can improve snapping of intersecting surfaces. // strictRegionSnap true; } // 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 true; // Layer thickness specification. This can be specified either through the // 'thicknessModel' parameter (new) or by specifying the individual // settings. The parameters are the cell height of the cells next to the // wall ('firstLayerThickness'), the cell height of the cells next to the // bulk ('finalLayerThickness'), the expansionRatio ('expansionRatio') and // the overall thickness of all layers ('thickness'). //- specification of firstLayerThickness and overallThicknes, calculates // needed expansionRatio. // thicknessModel firstAndOverall; //- specification of firstLayerThickness and expansionRatio. // thicknessModel firstAndExpansion; //- specification of finalLayerThickness and expansionRatio. // thicknessModel finalAndExpansion; //- specification of thickness and expansionRatio. // thicknessModel overallAndExpansion; //- specification of firstLayerThickness and finalLayerThickness. The // firstLayerThickness is always absolute, the finalLayerThickness is // always relative, independent of the relativeSizes setting // thicknessModel firstAndRelativeFinal; // 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; // 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 0.1; // Per final patch or faceZone (so not geometry!) the layer information: // - whether to use relative or absolute sizes // - thicknessModel (or individual settings) // - minimum thickness // // Note: mesh shrinking 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 { sphere.stl_firstSolid { nSurfaceLayers 1; } maxY { nSurfaceLayers 1; // Per patch layer data expansionRatio 1.3; finalLayerThickness 0.3; minThickness 0.1; } // Disable any mesh shrinking and layer addition on any point of // a patch by setting nSurfaceLayers to 0 frozenPatches { nSurfaceLayers 0; } } // 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; // Advanced settings // Static analysis of starting mesh // When not to extrude surface. 0 is flat surface, 90 is when two faces // are perpendicular. Note: was not working correctly < 1806 featureAngle 120; // When to merge patch faces. Default is featureAngle. Useful when // featureAngle is large. //mergePatchFacesAngle 45; // 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; // Choice of mesh shrinking algorithm // Optional mesh shrinking algorithm (default is displacementMedialAxis) // The displacementMotionSolver is a wrapper around the displacement // motion solvers. It needs specification of the solver to use and // its control dictionary. //meshShrinker displacementMotionSolver; //solver displacementLaplacian; //displacementLaplacianCoeffs //{ // diffusivity quadratic inverseDistance // ( // sphere.stl_firstSolid // maxY // ); //} // Note that e.g. displacementLaplacian needs entries in // fvSchemes, fvSolution. Also specify a minIter > 1 when solving // cellDisplacement since otherwise solution might not be sufficiently // accurate on points. // Medial axis analysis (for use with default displacementMedialAxis) // Angle used to pick up medial axis points // Note: changed(corrected) w.r.t 1.7.x! 90 degrees corresponds to 130 // in 1.7.x. minMedialAxisAngle 90; // Reduce layer growth where ratio thickness to medial // distance is large maxThicknessToMedialRatio 0.3; // Number of smoothing iterations of interior mesh movement direction nSmoothNormals 3; // Optional: limit the number of steps walking away from the surface. // Default is unlimited. //nMedialAxisIter 10; // Optional: smooth displacement after medial axis determination. // default is 0. //nSmoothDisplacement 90; // (wip)Optional: do not extrude any point where // (false) : all surrounding faces are not fully extruded // (true) : all surrounding points are not extruded // Default is false. //detectExtrusionIsland true; // Optional: do not extrude around sharp edges if both faces are not // fully extruded i.e. if one of the faces on either side would // become a wedge. // Default is 0.5*featureAngle. Set to -180 always attempt extrusion //layerTerminationAngle 25; // Optional: disable shrinking of edges that have one (or two) points // on an extruded patch. // Default is false to enable single/two cell thick channels to still // have layers. In <=1806 this was true by default. On larger gaps it // should have no effect. //disableWallEdges true; // 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; // Mesh shrinking // Create buffer region for new layer terminations, i.e. gradually // step down number of layers. Set to <0 to terminate layer in one go. 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 { // Specify mesh quality constraints in separate dictionary so can // be reused (e.g. checkMesh -meshQuality) #include "meshQualityDict" // Optional : some meshing phases allow usage of relaxed rules. // See e.g. addLayersControls::nRelaxedIter. relaxed { // Maximum non-orthogonality allowed. Set to 180 to disable. maxNonOrtho 75; } // Advanced // Number of error distribution iterations nSmoothScale 4; // amount to scale back displacement at error points errorReduction 0.75; } // Advanced //// Debug flags //debugFlags //( // mesh // write intermediate meshes // intersections // write current mesh intersections as .obj files // featureSeeds // write information about explicit feature edge // // refinement // attraction // write attraction as .obj files // layerInfo // write information about layers //); // //// Write flags //writeFlags //( // scalarLevels // write volScalarField with cellLevel for postprocessing // layerSets // write cellSets, faceSets of faces in layer // layerFields // write volScalarField for layer coverage //); //// Format for writing lines. E.g. leak path. Default is vtk format. //setFormat ensight; // Merge tolerance. Is fraction of overall bounding box of initial mesh. // Note: the write tolerance needs to be higher than this. mergeTolerance 1e-6; // ************************************************************************* //