openfoam/tutorials/multiphase/interDyMFoam/RAS/mixerVesselAMI/system/snappyHexMeshDict

/*--------------------------------*- 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
{
    vessel.stl
    {
        name vessel;
        type triSurfaceMesh;
        regions
        {
            vessel
            {
                name vessel;
            }
        }
    }

    gasInlet.stl
    {
        name gasInlet;
        type triSurfaceMesh;
        regions
        {
            gasInlet
            {
                name gasInlet;
            }
        }
    }

    outlet.stl
    {
        name outlet;
        type triSurfaceMesh;
        regions
        {
            outlet
            {
                name outlet;
            }
        }
    }

    shaftRotating.stl
    {
        name shaftRotating;
        type triSurfaceMesh;
        regions
        {
            shaftRotating
            {
                name shaftRotating;
            }
        }
    }

    shaft.stl
    {
        name shaft;
        type triSurfaceMesh;
        regions
        {
            shaft
            {
                name shaft;
            }
        }
    }

    sparger.stl
    {
        name sparger;
        type triSurfaceMesh;
        regions
        {
            sparger
            {
                name sparger;
            }
        }
    }

    stirrer.stl
    {
        name stirrer;
        type triSurfaceMesh;
        regions
        {
            stirrer
            {
                name stirrer;
            }
        }
    }

    baffles.stl
    {
        name baffles;
        type triSurfaceMesh;
        regions
        {
            baffles
            {
                name baffles;
            }
        }
    }

    rotating.stl
    {
        name rotating;
        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 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 3000000;

    // 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 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 "gasInlet.eMesh";
           levels ((1 1));
        }
        {
           file "vessel.eMesh";
           levels ((1 1));
        }
        {
           file "outlet.eMesh";
           levels ((1 1));
        }

    );

    // 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
    {
        vessel
        {
            level (1 2);
            patchInfo
            {
                type wall;
                inGroups (meshedWalls);
            }
        }

        gasInlet
        {
            level (0 1);
            patchInfo
            {
                type patch;
            }
        }

        outlet
        {
            level (0 1);
            patchInfo
            {
                type patch;
            }
        }

        shaftRotating
        {
            level (1 1);
            patchInfo
            {
                ${...vessel.patchInfo}
            }
        }

        shaft
        {
            level (1 1);
            patchInfo
            {
                ${...vessel.patchInfo}
            }
        }

        sparger
        {
            level (1 1);
            patchInfo
            {
                ${...vessel.patchInfo}
            }
        }

        stirrer
        {
            level (1 1);
            patchInfo
            {
                ${...vessel.patchInfo}
            }
        }

        baffles
        {
            level (1 1);
            patchInfo
            {
                ${...vessel.patchInfo}
            }
        }

        rotating
        {
            level (1 2);
            cellZone rotating;
            faceZone rotating;
            cellZoneInside insidePoint;
            insidePoint (0 0.1 0.5);
        }
    }

    // Feature angle:
    // - used if min and max refinement level of a surface differ
    // - used if feature snapping (see snapControls below) is used
    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
    //   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
    {
    }

    // 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 0.1 1.0);

    // 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;

    // Maximum relative distance for points to be attracted by surface.
    // True distance is this factor times local maximum edge length.
    // Note: changed(corrected) w.r.t 1.7.x! (1.7.x used 2* tolerance)
    tolerance 3.0;

    // 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 15;

        // 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;
}

// 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 in one of four ways
    // - expansionRatio and finalLayerThickness (cell nearest internal mesh)
    // - expansionRatio and firstLayerThickness (cell on surface)
    // - overall thickness and firstLayerThickness
    // - overall thickness and finalLayerThickness

        // 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;

        // Wanted thickness of the layer next to the wall.
        // If relativeSizes this is relative to undistorted size of cell
        // outside layer.
        //firstLayerThickness 0.3;

        // Wanted overall thickness of layers.
        // If relativeSizes this is relative to undistorted size of cell
        // outside layer.
        //thickness 0.5


    // 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 0.25;


    // Per final patch (so not geometry!) the layer information
    // Note: This 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
    {
        vessel
        {
            nSurfaceLayers      1;
            expansionRatio      1.3;
            finalLayerThickness 0.5;
            minThickness        0.1;
        }
    }

    // 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

    // When not to extrude surface. 0 is flat surface, 90 is when two faces
    // are perpendicular
    featureAngle 60;

    // At non-patched sides allow mesh to slip if extrusion direction makes
    // angle larger than slipFeatureAngle.
    slipFeatureAngle 30;

    // Maximum number of snapping relaxation iterations. Should stop
    // before upon reaching a correct mesh.
    nRelaxIter 10;

    // 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 1.7.x! 90 degrees corresponds to 130
    // in 1.7.x.
    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;

    // 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
{
    // 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. This has to be a positive number for tracking
    // to work. Set to very negative number (e.g. -1E30) to
    // disable.
    //    <0 = inside out tet,
    //     0 = flat tet
    //     1 = regular tet
    minTetQuality 1e-9;

    // 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;

    //- If >0 : preserve single cells with all points on the surface if the
    //  resulting volume after snapping (by approximation) is larger than
    //  minVolCollapseRatio times old volume (i.e. not collapsed to flat cell).
    //  If <0 : delete always.
    //minVolCollapseRatio 0.5;

    // Advanced

    // Number of error distribution iterations
    nSmoothScale 4;
    // amount to scale back displacement at error points
    errorReduction 0.75;

    // 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

// Merge tolerance. Is fraction of overall bounding box of initial mesh.
// Note: the write tolerance needs to be higher than this.
mergeTolerance 1e-6;

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