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IDProjectCategoryView StatusDate SubmittedLast Update
0000527OpenFOAMBugpublic2012-05-02 10:562014-10-16 10:16
Reporteruser427Assigned Touser4 
PrioritynormalSeverityminorReproducibilityalways
Status resolvedResolutionfixed 
PlatformLinuxOSOtherOS Version(please specify)
Summary0000527: Regular expressions do not work in snappyHexMeshDict refinementRegions
DescriptionYou can select refinementSurfaces using regular expressions, e.g.

refinementSurfaces
    {
      "(BPID|GOPT|GRWS).*"
        { level (0 1); }
    }

It works for layers too but not the refinementRegions entry. All used regions have to be specified manually.
Steps To ReproduceUse something like that:

    refinementRegions
    {
      "VRES0.00\.stl"
        {
         mode inside;
         levels ((0 4));
        }
Additional InformationReally cool would be if you were able to use regular expressions groups and reference them, e.g.

    refinementRegions
    {
      "VRES0(.)00\.stl"
        {
         mode inside;
         levels ((0 $1));
        }
}
TagsNo tags attached.

Activities

user427

2012-05-03 09:34

  ~0001302

A working snappyHexMeshDict example: See the regular expressions in the refinementSurfaces and layer dictionaries. Trying to use a similiar regular expression in the refinementRegions dict (see steps to reproduce) results in a failure.


/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version 2.0;
    format ascii;
    class dictionary;
    object snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// Which of the steps to run
castellatedMesh true;
snap true;
addLayers 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
{
  BPID0030_windTunnel.stl
    { type triSurfaceMesh; }
  GOPT0960_A2_bodySmooth.stl
    { type triSurfaceMesh; }
  GOPT0960_B12_backFastback.stl
    { type triSurfaceMesh; }
  GRWS0960_O12_frontWheel.stl
    { type triSurfaceMesh; }
  GRWS0960_O12_rearWheel.stl
    { type triSurfaceMesh; }
  GOPT0960_O12_mirrors.stl
    { type triSurfaceMesh; }
  BPID0860_frontWheelarm.stl
    { type triSurfaceMesh; }
  BPID0860_rearWheelarm.stl
    { type triSurfaceMesh; }
  BWAL0860_belt.stl
    { type triSurfaceMesh; }
  GOPT0960_D12_splitter.stl
    { type triSurfaceMesh; }
  BPID0860_scoopFlap_6deg.stl
    { type triSurfaceMesh; }
  GOPT0960_12_mountingRadiator.stl
    { type triSurfaceMesh; }
  GOPT0960_D2_midPipe.stl
    { type triSurfaceMesh; }
  GOPT0960_D12_curvedPipe.stl
    { type triSurfaceMesh; }

  VRES0300.stl
    { type triSurfaceMesh; }
  VRES0400.stl
    { type triSurfaceMesh; }
  VRES0500.stl
    { type triSurfaceMesh; }
  VRES0600.stl
    { type triSurfaceMesh; }
  VRES0700.stl
    { type triSurfaceMesh; }
};



// 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 200000000;

    // 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 2;



    // 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
    (
    );



    // 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
    {
      "(BPID|GOPT|GRWS).*"
    { level (5 6); }
    }

    // Resolve sharp angles
    resolveFeatureAngle 60;


    // 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
    {
      VRES0300.stl
        {
          mode inside;
          levels ((0 3));
        }
      VRES0400.stl
        {
          mode inside;
          levels ((0 4));
        }
      VRES0500.stl
        {
          mode inside;
          levels ((0 5));
        }
      VRES0600.stl
        {
          mode inside;
          levels ((0 6));
        }
      VRES0700.stl
        {
          mode inside;
          levels ((0 7));
        }
    }


    // 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 (300 250 200);
    locationInMesh (-900 0 200);


    // 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
    {
    ".*"
         {
           nSurfaceLayers 5;
        }
    }

    // Expansion factor for layer mesh
    expansionRatio 1.4;

    //- 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.
    // is the thickness of the layer furthest away from the wall.
    // See relativeSizes parameter.
    finalLayerThickness 1;

    //- Minimum thickness of cell layer. If for any reason layer
    // cannot be above minThickness do not add layer.
    // Relative to undistorted size of cell outside 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
    // make straight angle.
    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;
}



// 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 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 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;

    //- 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;


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

Issue History

Date Modified Username Field Change
2012-05-02 10:56 user427 New Issue
2012-05-03 09:34 user427 Note Added: 0001302
2014-10-16 10:16 user4 Status new => resolved
2014-10-16 10:16 user4 Fixed in Version => 2.2.x
2014-10-16 10:16 user4 Resolution open => fixed
2014-10-16 10:16 user4 Assigned To => user4