ENH: snappyHexMesh: directional refinememt.

Basic directional refinement:
- only for coordinate aligned meshes
- only for refinementRegions
See the mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement
tutorial.

src/mesh/snappyHexMesh/snappyHexMeshDriver/snappyRefineDriver.C

@@ -1684,8 +1684,7 @@ Foam::label Foam::snappyRefineDriver::directionalShellRefine
                     const_cast<Time&>(mesh.time())++;
                 }
 
-                PackedBoolList isRefineCell(mesh.nCells());
+                const bitSet isRefineCell(mesh.nCells(), cellsToRefine);
-                isRefineCell.set(cellsToRefine);
 
                 autoPtr<mapPolyMesh> map
                 (

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/Allrun

@@ -0,0 +1,12 @@
+#!/bin/sh
+cd ${0%/*} || exit 1    # Run from this directory
+
+# Source tutorial run functions
+. $WM_PROJECT_DIR/bin/tools/RunFunctions
+
+application="$(getApplication)"
+
+runApplication blockMesh
+runApplication snappyHexMesh
+
+#------------------------------------------------------------------------------

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/constant/thermophysicalProperties

@@ -0,0 +1,47 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  dev                                   |
+|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    location    "constant";
+    object      thermophysicalProperties;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+thermoType
+{
+    type            hePsiThermo;
+    mixture         pureMixture;
+    transport       const;
+    thermo          hConst;
+    equationOfState perfectGas;
+    specie          specie;
+    energy          sensibleInternalEnergy;
+}
+
+mixture // air at room temperature (293 K)
+{
+    specie
+    {
+        molWeight   28.9;
+    }
+    thermodynamics
+    {
+        Cp          1005;
+        Hf          0;
+    }
+    transport
+    {
+        mu          1.82e-05;
+        Pr          0.71;
+    }
+}
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/constant/turbulenceProperties

@@ -0,0 +1,26 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  dev                                   |
+|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      turbulenceProperties;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+simulationType RAS;
+
+RAS
+{
+    RASModel            kOmegaSST;
+    turbulence          on;
+    printCoeffs         on;
+}
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/blockMeshDict

@@ -0,0 +1,85 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  dev                                   |
+|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      blockMeshDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+scale   1;
+
+vertices
+(
+    (-0.5 -0.1 -0.5)
+    ( 2   -0.1 -0.5)
+    ( 2    0.1 -0.5)
+    (-0.5  0.1 -0.5)
+    (-0.5 -0.1  0.5)
+    ( 2   -0.1  0.5)
+    ( 2    0.1  0.5)
+    (-0.5  0.1  0.5)
+);
+
+blocks
+(
+    hex (0 1 2 3 4 5 6 7) (25 2 10) simpleGrading (1 1 1)
+);
+
+edges
+(
+);
+
+boundary
+(
+    frontAndBack
+    {
+        type patch;
+        faces
+        (
+            (3 7 6 2)
+            (1 5 4 0)
+        );
+    }
+    inlet
+    {
+        type patch;
+        faces
+        (
+            (0 4 7 3)
+        );
+    }
+    outlet
+    {
+        type patch;
+        faces
+        (
+            (2 6 5 1)
+        );
+    }
+    lowerWall
+    {
+        type wall;
+        faces
+        (
+            (0 3 2 1)
+        );
+    }
+    upperWall
+    {
+        type patch;
+        faces
+        (
+            (4 5 6 7)
+        );
+    }
+);
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/controlDict

@@ -0,0 +1,48 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  dev                                   |
+|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      controlDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+application     snappyHexMesh;
+
+startFrom       startTime;
+
+startTime       0;
+
+stopAt          endTime;
+
+endTime         1000;
+
+deltaT          1;
+
+writeControl    timeStep;
+
+writeInterval   50;
+
+purgeWrite      0;
+
+writeFormat     ascii;
+
+writePrecision  8;
+
+writeCompression off;
+
+timeFormat      general;
+
+timePrecision   6;
+
+runTimeModifiable true;
+
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/fvSchemes

@@ -0,0 +1,74 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  dev                                   |
+|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      fvSchemes;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+ddtSchemes
+{
+    default         steadyState;
+}
+
+gradSchemes
+{
+    default         Gauss linear;
+
+    limited         cellLimited Gauss linear 1;
+    grad(U)         $limited;
+    grad(k)         $limited;
+    grad(omega)     $limited;
+}
+
+divSchemes
+{
+    default         none;
+
+    div(phi,U)      bounded Gauss linearUpwind limited;
+
+    turbulence      bounded Gauss upwind;
+    energy          bounded Gauss linearUpwind limited;
+
+    div(phi,k)      $turbulence;
+    div(phi,omega)  $turbulence;
+
+    div(phi,e)      $energy;
+    div(phi,K)      $energy;
+    div(phi,Ekp)    $energy;
+
+    div(phid,p)     Gauss upwind;
+    div((phi|interpolate(rho)),p)  bounded Gauss upwind;
+
+    div(((rho*nuEff)*dev2(T(grad(U)))))    Gauss linear;
+}
+
+laplacianSchemes
+{
+    default         Gauss linear corrected;
+}
+
+interpolationSchemes
+{
+    default         linear;
+}
+
+snGradSchemes
+{
+    default         corrected;
+}
+
+wallDist
+{
+    method meshWave;
+}
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/fvSolution

@@ -0,0 +1,65 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  dev                                   |
+|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      fvSolution;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+solvers
+{
+    p
+    {
+        solver          GAMG;
+        smoother        GaussSeidel;
+        tolerance       1e-6;
+        relTol          0.01;
+    }
+
+    "(U|k|omega|e)"
+    {
+        solver          PBiCGStab;
+        preconditioner  DILU;
+        tolerance       1e-6;
+        relTol          0.1;
+    }
+}
+
+SIMPLE
+{
+    residualControl
+    {
+        p               1e-4;
+        U               1e-4;
+        "(k|omega|e)"   1e-4;
+    }
+
+    nNonOrthogonalCorrectors 0;
+    pMinFactor      0.1;
+    pMaxFactor      2;
+}
+
+relaxationFactors
+{
+    fields
+    {
+        p               0.7;
+        rho             0.01;
+    }
+    equations
+    {
+        U               0.3;
+        e               0.7;
+        "(k|omega)"     0.7;
+    }
+}
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/meshQualityDict

@@ -0,0 +1,21 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  plus                                  |
+|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
+|    \\/     M anipulation  |                                                 |
+\*---------------------------------------------------------------------------*/
+FoamFile
+{
+    version     2.0;
+    format      ascii;
+    class       dictionary;
+    object      meshQualityDict;
+}
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// Include defaults parameters from master dictionary
+#includeEtc "caseDicts/meshQualityDict"
+
+
+// ************************************************************************* //

tutorials/mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement/system/snappyHexMeshDict

@@ -0,0 +1,317 @@
+/*--------------------------------*- C++ -*----------------------------------*\
+| =========                 |                                                 |
+| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
+|  \\    /   O peration     | Version:  plus                                  |
+|   \\  /    A nd           | Web:      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;
+
+
+// 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
+{
+    NACA0012
+    {
+        type triSurfaceMesh;
+        file "NACA0012.obj";
+    }
+    wake
+    {
+        type searchableBox;
+        min (0.8 -0.1 -0.1);
+        max (2.0  0.1  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 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 100;
+
+    // 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
+    (
+    );
+
+
+
+    // 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
+    {
+        NACA0012
+        {
+            // Surface-wise min and max refinement level
+            level (2 2);
+
+            // Optional specification of patch type (default is wall). No
+            // constraint types (cyclic, symmetry) etc. are allowed.
+            patchInfo
+            {
+                type        wall;
+            }
+        }
+    }
+
+    // Resolve sharp angles on fridges
+    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
+    {
+        wake
+        {
+            mode        inside;
+
+            // Disable uniform refinement
+            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 0-1
+            //  - do one split in y and z direction. Note:the resulting mesh is
+            //    no longer compatible with e.g. dynamic
+            //    refinement/unrefinement.
+            levelIncrement  (0 1 (0 1 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 (-0.499 -0.0999 -0.499);
+
+
+    // 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 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;
+
+
+    // Feature snapping
+
+        //- Number of feature edge snapping iterations.
+        //  Leave out altogether to disable.
+        nFeatureSnapIter 10;
+
+        //- Detect (geometric) features by sampling the surface (default=false)
+        implicitFeatureSnap true;
+
+        //- Use castellatedMeshControls::features (default = true)
+        explicitFeatureSnap false;
+}
+
+
+
+// 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
+    {
+        "two.*"
+        {
+            nSurfaceLayers 3;
+        }
+        ground
+        {
+            nSurfaceLayers 3;
+        }
+        igloo
+        {
+            nSurfaceLayers 1;
+        }
+    }
+
+    // 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 0.5;
+
+    // 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 0.05;
+
+    // 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 180;
+
+    // Maximum number of snapping relaxation iterations. Should stop
+    // before upon reaching a correct mesh.
+    nRelaxIter 5;
+
+    // Stop layer growth on highly warped cells
+    maxFaceThicknessRatio 0.5;
+
+    // Smooth layer thickness over surface patches
+    nSmoothThickness 10;
+
+
+
+    //- Use displacementMotionSolver to shrink mesh
+    meshShrinker displacementMotionSolver;
+
+    //- Use laplacian for shrinking
+    solver displacementLaplacian;
+
+    displacementLaplacianCoeffs
+    {
+        diffusivity quadratic inverseDistance ("two.*" igloo);
+    }
+
+
+    // Create buffer region for new layer terminations
+    nBufferCellsNoExtrude -1;   //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
+{
+    #include "meshQualityDict"
+
+    // Advanced
+
+    //- Number of error distribution iterations
+    nSmoothScale 4;
+    //- Amount to scale back displacement at error points
+    errorReduction 0.75;
+}
+
+
+// Advanced
+
+// Merge tolerance. Is fraction of overall bounding box of initial mesh.
+// Note: the write tolerance needs to be higher than this.
+mergeTolerance 1e-6;
+
+//writeFlags (scalarLevels);
+
+// ************************************************************************* //