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[snappyHexMesh] Weird 90° corners after castellatedMesh |
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February 22, 2024, 21:35 |
Weird 90° corners after castellatedMesh
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New Member
Jahir Bahena
Join Date: Feb 2024
Location: Mexico
Posts: 7
Rep Power: 2 |
Hello.
This is my first post in this forum (lurking for a couple of months) and I hope it's not something trivial. I'm working with an internal mesh using blockMesh + snappyHexMesh (I just started using sHM) and after some reading I've reached a decent mesh (at least after using castellatedMesh). What's worrying me is that there's a wierd corner on a fairly simple part of my geometry which I believe shouldn't have much problem. This is my sHMDict: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v2312 | | \\ / 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 { inlet.stl { type triSurfaceMesh; name inlet; } outlet.stl { type triSurfaceMesh; name outlet; } atmosphere.stl { type triSurfaceMesh; name atmosphere; } walls1.stl { type triSurfaceMesh; name walls1; } walls2.stl { type triSurfaceMesh; name walls2; } /* refinementBox { type box; min (-1.0 -0.7 0.0); max ( 8.0 0.7 2.5); } */ } // 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 10000000; // 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 20000000; // 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 5; // 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/triSurface for now. features ( /*{ file "tanque.eMesh"; level 6; }*/ ); // 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 { inlet { // Surface-wise min and max refinement level level (0 0); patchInfo { type patch; } } outlet { // Surface-wise min and max refinement level level (0 0); patchInfo { type patch; } } atmosphere { // Surface-wise min and max refinement level level (0 0); patchInfo { type patch; } } walls1 { // Surface-wise min and max refinement level level (0 0); } walls2 { // Surface-wise min and max refinement level level (1 1); } } // Resolve sharp angles resolveFeatureAngle 5; // 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 { /*tanque.stl { mode inside; levels ((0 2)); }*/ } // 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 (1 1 1); // 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; } After moving up to the next step, what would be your advice to have a nice refinement? EDIT: Turned out to be something trivial, the gap was formed because the element size 0 was larger than the length of that part of the geometry. Last edited by Jahir; February 23, 2024 at 23:06. |
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