关于snappyHexMesh网格无法很好snap贴合的咨询

[DY大世界]

各位大神，我目前使用snappyHexMesh划分一个流场网格，网格内的三角形是外部导入的stl文件。

blochMeshDict字典为

scale   1.0;

vertices
(
    (-500 -400 -200)
    (1500 -400 -200)
    (-500 1000 -200)
    (1500 1000 -200)
    (-500 -400 400)
    (1500 -400 400)
    (-500 1000 400)
    (1500 1000 400)
);

blocks
(
    hex (0 1 3 2 4 5 7 6) (100 70 30) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
    left
    {
        type patch;
        faces
        (
            (0 4 6 2)
        );
    }
    right
    {
        type patch;
        faces
        (
            (5 1 3 7)
        );
    }
    frontAndBack
    {
        type empty;
        faces
        (
            (0 2 3 1)
            (4 5 7 6)
        );
    }
);

mergePatchPairs
(
);

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

surfaceFeatureExtractDict文件为

wedge.stl
{
    // How to obtain raw features (extractFromFile || extractFromSurface)
    extractionMethod    extractFromSurface;

    // Mark edges whose adjacent surface normals are at an angle less
    // than includedAngle as features
    // - 0  : selects no edges
    // - 180: selects all edges
    includedAngle       150;

    // Write options

    // Write features to obj format for postprocessing
    writeObj            yes;
}

snappyHexMeshDict文件为

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
{
    wedge.stl
    {
        type triSurfaceMesh;
        name wedge;
    }

    //- 
    box
    {
        type    searchableBox;
        min  (-200 -200 -100);
        max  (1200 800 200);
    }
}


// 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;

    // 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 "wedge.extendedFeatureEdgeMesh";
            level 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
    {
        wedge
        {
            // Surface-wise min and max refinement level
            level (2 3);
        }
    }

    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
    {
        box
        {
            mode inside;
            levels ((1E15 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.
    // This is an outside point locationInMesh (-0.033 -0.033 0.0033);
    locationInMesh (-48 -38 -18); // Inside point

    // 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 40;

    //- Number of mesh displacement relaxation iterations.
    nSolveIter 300;

    //- 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 30;

        //- Detect (geometric) features by sampling the surface
        implicitFeatureSnap false;

        //- Use castellatedMeshControls::features
        explicitFeatureSnap true;

        //- Detect features between multiple surfaces
        //  (only for explicitFeatureSnap, default = false)
        multiRegionFeatureSnap true;
}



// 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
    {
        "wedge_.*"
        {
            nSurfaceLayers 1;
        }
    }

    // Expansion factor for layer mesh
    expansionRatio 1.0;

    // Minimum thickness of cell layer. If for any reason layer
    // cannot be above minThickness do not add layer.
    // See relativeSizes parameter.
    minThickness 0.25;
}



// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
    #include "meshQualityDict"

    // 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

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


// Advanced

// Write flags
writeFlags
(
    scalarLevels    // write volScalarField with cellLevel for postprocessing
    layerSets       // write cellSets, faceSets of faces in layer
    layerFields     // write volScalarField for layer coverage
);


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


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

但是在三角形固体边界处网格畸变很大，贴合总是不好，感觉就是没有贴合

调试了很多次都是这样，搞不懂是什么原因，希望各位老师指点。感谢！

[东岳]

我看你画的是二维的blockMesh，改成三维的就好了，snappyHexMesh做二维网格不能用你用的这种方法，会出现你这个问题。需要做成三维的，再投影成2伟的

[DY大世界]

@东岳 感谢李老师解答，我再试试