相同snappyHexMeshDict和地形stl条件下，blockMeshDict增大导致网格划分失败
-
如题，我使用相同snappyhexmesh文件来对blocckmesh网格和地形stl文件进行划分，当范围选择为2000m*2000m*630m时（case1），可以进行正常的网格划分和运算； 当范围增大到3000m*3000m*630m时（case2），无法进行正常运算，case2会发散。
（具体算例文件：wcase.zip ，stl文件文件过大无法上传）
（只修改了xmin,xmax,ymin,ymax,并且网格大小也一致，而且两个case划分好网格以后checkMesh都没问题）。运行结果如下：
case1正常运行
case2发散：Time = 178s smoothSolver: Solving for Ux, Initial residual = 0.446597, Final residual = 0.0256856, No Iterations 3 smoothSolver: Solving for Uy, Initial residual = 0.422256, Final residual = 0.0231428, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 0.497265, Final residual = 0.0275248, No Iterations 3 GAMG: Solving for p, Initial residual = 0.0065485, Final residual = 0.000418695, No Iterations 4 time step continuity errors : sum local = 1.68504e+18, global = 1.42803e+16, cumulative = 9.69486e+16 ExecutionTime = 15.72 s ClockTime = 18 s Time = 179s [38] #0 Foam::error::printStack(Foam::Ostream&) at ??:? [38] #1 Foam::sigFpe::sigHandler(int) at ??:? [38] #2 ? in "/lib64/libc.so.6" [38] #3 Foam::pow3(Foam::Field<double>&, Foam::UList<double> const&) at ??:? [38] #4 void Foam::pow3<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? [38] #5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::pow3<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? [38] #6 Foam::LESModels::WALE<Foam::incompressibleMomentumTransportModel>::k(Foam::GeometricField<Foam::Tensor<double>, Foam::fvPatchField, Foam::volMesh> const&) const at ??:? [38] #7 Foam::LESModels::WALE<Foam::incompressibleMomentumTransportModel>::correctNut() at ??:? [38] #8 ? at ??:? [38] #9 __libc_start_main in "/lib64/libc.so.6" [38] #10 ? at ??:? [m3cn2707:519656:0:519656] Caught signal 8 (Floating point exception: tkill(2) or tgkill(2)) ==== backtrace ==== 0 /usr/lib64/libucs.so.0(+0x17970) [0x2b9da57c4970] 1 /usr/lib64/libucs.so.0(+0x17c23) [0x2b9da57c4c23] 2 /lib64/libc.so.6(gsignal+0x37) [0x2b9c34fa7387] 3 /public1/home/sch10341/soft/openfoam10/OpenFOAM-10/platforms/linux64IcxDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam4pow3ERNS_5FieldIdEERKNS_5UListIdEE+0xae) [0x2b9c340b32ee] 4 /public1/home/sch10341/soft/openfoam10/OpenFOAM-10/platforms/linux64IcxDPInt32Opt/lib/libincompressibleMomentumTransportModels.so(_ZN4Foam4pow3INS_12fvPatchFieldENS_7volMeshEEEvRNS_14GeometricFieldIdT_T0_EERKS6_+0x31) [0x2b9c30c1c421] 5 /public1/home/sch10341/soft/openfoam10/OpenFOAM-10/platforms/linux64IcxDPInt32Opt/lib/libincompressibleMomentumTransportModels.so(_ZN4Foam4pow3INS_12fvPatchFieldENS_7volMeshEEENS_3tmpINS_14GeometricFieldIdT_T0_EEEERKS7_+0x188) [0x2b9c30c1bad8] 6 /public1/home/sch10341/soft/openfoam10/OpenFOAM-10/platforms/linux64IcxDPInt32Opt/lib/libincompressibleMomentumTransportModels.so(_ZNK4Foam9LESModels4WALEINS_36incompressibleMomentumTransportModelEE1kERKNS_14GeometricFieldINS_6TensorIdEENS_12fvPatchFieldENS_7volMeshEEE+0x758) [0x2b9c30cb6da8] 7 /public1/home/sch10341/soft/openfoam10/OpenFOAM-10/platforms/linux64IcxDPInt32Opt/lib/libincompressibleMomentumTransportModels.so(_ZN4Foam9LESModels4WALEINS_36incompressibleMomentumTransportModelEE10correctNutEv+0x12d) [0x2b9c30cb637d] 8 simpleFoam() [0x43326c] 9 /lib64/libc.so.6(__libc_start_main+0xf5) [0x2b9c34f93555] 10 simpleFoam() [0x41c588] ===================1、checkMesh结果如图所示：
case1：
case2：
2、blcokMeshDict文件如下所示:
case1：backgroundMesh { xMin 4000; xMax 6100; yMin 4400; yMax 6500; zMin -60; zMax 600; xCells 70; yCells 70; zCells 22; } convertToMeters 1; vertices ( ($!backgroundMesh/xMin $!backgroundMesh/yMin $!backgroundMesh/zMin) ($!backgroundMesh/xMax $!backgroundMesh/yMin $!backgroundMesh/zMin) ($!backgroundMesh/xMax $!backgroundMesh/yMax $!backgroundMesh/zMin) ($!backgroundMesh/xMin $!backgroundMesh/yMax $!backgroundMesh/zMin) ($!backgroundMesh/xMin $!backgroundMesh/yMin $!backgroundMesh/zMax) ($!backgroundMesh/xMax $!backgroundMesh/yMin $!backgroundMesh/zMax) ($!backgroundMesh/xMax $!backgroundMesh/yMax $!backgroundMesh/zMax) ($!backgroundMesh/xMin $!backgroundMesh/yMax $!backgroundMesh/zMax) ); blocks ( hex (0 1 2 3 4 5 6 7) ( $!backgroundMesh/xCells $!backgroundMesh/yCells $!backgroundMesh/zCells ) simpleGrading (1 1 1) ); boundary ( west { type patch; faces ( (0 3 7 4) ); } east { type patch; faces ( (1 5 6 2) ); } south { type patch; faces ( (0 4 5 1) ); } north { type patch; faces ( (3 2 6 7) ); } ground { type wall; faces ( (0 1 2 3) ); } top { type patch; faces ( (4 7 6 5) ); } );case2：（只修改了xmin,xmax,ymin,ymax）
backgroundMesh { backgroundMesh { xMin 3500; xMax 6500; yMin 4000; yMax 7000; zMin -60; zMax 600; xCells 100; yCells 100; zCells 22; } convertToMeters 1; vertices ( ($!backgroundMesh/xMin $!backgroundMesh/yMin $!backgroundMesh/zMin) ($!backgroundMesh/xMax $!backgroundMesh/yMin $!backgroundMesh/zMin) ($!backgroundMesh/xMax $!backgroundMesh/yMax $!backgroundMesh/zMin) ($!backgroundMesh/xMin $!backgroundMesh/yMax $!backgroundMesh/zMin) ($!backgroundMesh/xMin $!backgroundMesh/yMin $!backgroundMesh/zMax) ($!backgroundMesh/xMax $!backgroundMesh/yMin $!backgroundMesh/zMax) ($!backgroundMesh/xMax $!backgroundMesh/yMax $!backgroundMesh/zMax) ($!backgroundMesh/xMin $!backgroundMesh/yMax $!backgroundMesh/zMax) ); blocks ( hex (0 1 2 3 4 5 6 7) ( $!backgroundMesh/xCells $!backgroundMesh/yCells $!backgroundMesh/zCells ) simpleGrading (1 1 1) ); boundary ( west { type patch; faces ( (0 3 7 4) ); } east { type patch; faces ( (1 5 6 2) ); } south { type patch; faces ( (0 4 5 1) ); } north { type patch; faces ( (3 2 6 7) ); } ground { type wall; faces ( (0 1 2 3) ); } top { type patch; faces ( (4 7 6 5) ); } ); }3、snappyHexMeshDict文件如下：
// Which of the steps to run castellatedMesh true; snap true; 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 { terrain { type triSurfaceMesh; file "km8LS.stl"; } }; // 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 <= minimumRefine are selected for refinement. Note: // it will at least do one iteration (unless the number of cells // to refine is 0) 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 its edges. // This is a featureEdgeMesh, read from constant/geometry for now. features ( //{ // file "someLine.eMesh"; // level 2; //} ); // 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 { terrain { // Surface-wise min and max refinement level level (2 2); // Optional region-wise level specification /* regions { windTurbine { level (3 3); } } */ //- 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) // faceZone sphere; // cellZone sphere; // mode inside; // outside/insidePoint } } resolveFeatureAngle 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 // 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. refinementRegions { // sphere.stl //{ // mode distance; // levels ((1.0 5) (2.0 3)); //} } // 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 insidePoint is kept. // NOTE: This point should never be on a face, always inside a cell, even // after refinement. insidePoint (5000 5500 300); // 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 true; // Per final patch (so not geometry!) the layer information layers { } // Expansion factor for layer mesh expansionRatio 1.0; // Wanted thickness of final added cell layer. If multiple layers // is the thickness of the layer furthest away from the wall. // Relative to undistorted size of cell outside layer. // See relativeSizes parameter. finalLayerThickness 0.3; // Minimum thickness of cell layer. If for any reason layer // cannot be above minThickness do not add layer. // See relativeSizes parameter. minThickness 0.25; // 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 17x! (didn't do anything in 17x) nGrow 0; // Advanced settings // When not to extrude surface. 0 is flat surface, 90 is when two faces // are perpendicular featureAngle 60; // Maximum number of snapping relaxation iterations. Should stop // before upon reaching a correct mesh. nRelaxIter 5; // Number of smoothing iterations of surface normals nSmoothSurfaceNormals 1; // Number of smoothing iterations of interior mesh movement direction nSmoothNormals 3; // Smooth layer thickness over surface patches nSmoothThickness 10; // Stop layer growth on highly warped cells maxFaceThicknessRatio 0.5; // Reduce layer growth where ratio thickness to medial // distance is large maxThicknessToMedialRatio 0.3; // Angle used to pick up medial axis points // Note: changed(corrected) w.r.t 16x! 90 degrees corresponds to 130 in 16x. minMedianAxisAngle 90; // 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 nRelaxIter it uses the settings in meshQualityControls, // after nRelaxIter it uses the values in meshQualityControls::relaxed. nRelaxedIter 20; } // 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 cell pyramid volume relative to min bounding box length^3 // Set to a fraction of the smallest cell volume expected. // Set to very negative number (e.g. -1e30) to disable. minVol -1e30; //- Minimum quality of the tet formed by the face-centre // and variable base point minimum decomposition triangles and // the cell centre. Set to very negative number (e.g. -1e30) to // disable. // <0 = inside out tet, // 0 = flat tet // 1 = regular tet minTetQuality 1e-30; //- 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; //- minFaceWeight (0 -> 0.5) minFaceWeight 0.05; //- minVolRatio (0 -> 1) minVolRatio 0.01; //- Number of error distribution iterations nSmoothScale 4; //- Amount to scale back displacement at error points errorReduction 0.75; relaxed { //- Maximum non-orthogonality allowed. Set to 180 to disable. maxNonOrtho 75; } } mergeTolerance 1e-6;
