[sabbraxcaddabra]

Hello everyone! I`m very new in OpenFOAM and in using snappyHexMesh utility and not clearly understand the problem i face with

I try to simulate the flow around a bullet or a projectile and the mesh at all is fine(i have a 99.2% of layers coverage), but in corners at nose and boattail there are less layers (on pictures)
Now i have read a lot of threads on this forum and try increase resolveFeatureAngle to solve this problem. But the quality of my mesh doesnt improved.


Here is all my project
https://disk.yandex.ru/d/s1lt1GIX8SU_kg

And all my snappeHexMeshDict

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |				
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  9                                   	
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       dictionary;
    object      snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// Which of the steps to run
castellatedMesh true;
snap            true;
addLayers       true;


geometry
{
    shell1.stl
    {
        type triSurfaceMesh;
        name projectile_stlSurface;

//To get regions in the STL

        regions
        {
            projectile  // Named region in the STL file
            {
                name projectile;    // User-defined patch name
            }

        }
    }

    refinementBox
    {
        type searchableBox;
        min (-0.5 -0.15 -0.15);
        max (0.75 0.15 0.15);
    }

};

// Settings for the castellatedMesh generation.
castellatedMeshControls
{

    // Refinement parameters
    // ~~~~~~~~~~~~~~~~~~~~~

    maxLocalCells 500000;

    maxGlobalCells 10000000;

    minRefinementCells 0;

    maxLoadUnbalance 0.10;

    nCellsBetweenLevels 3;

    // Explicit feature edge refinement
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    features
    (

        {
            file "shell1.eMesh";
            level 6;
          //level 4;
        }

    );

    // Surface based refinement
    // ~~~~~~~~~~~~~~~~~~~~~~~~

    refinementSurfaces
    {

        projectile_stlSurface
        {
	    // global
            // Surface-wise min and max refinement level
            level (7 7);
        }

    }

    // Feature angle:
    // resolveFeatureAngle 30;		//recommended
    resolveFeatureAngle 60;		//To avoid too much refinement with curvature

    planarAngle 30;

    // Region-wise refinement
    // ~~~~~~~~~~~~~~~~~~~~~~

    refinementRegions
    {
        refinementBox
        {
            mode inside;        	// inside - outside
            levels ((4 4));     	// min max

            //mode distance;        	// 
            //levels ((0.1 1));     	//first number distance normal to the surface in both direction
        }
    }

    // Mesh selection
    // ~~~~~~~~~~~~~~

    locationInMesh (2.0 0.5 0.5);

    allowFreeStandingZoneFaces true;

}

// Settings for the snapping.
snapControls
{
    // nSmoothPatch 2;	//recommended
    nSmoothPatch 10;	//improved

    tolerance 2.0;
    //tolerance 1.0;

    nSolveIter 5;	//recommended
    //nSolveIter 100;	//improved

    nRelaxIter 5;	//recommended
    //nRelaxIter 10;	//improved	10-20-50

    // Feature snapping

    nFeatureSnapIter 3	//recommended
    //nFeatureSnapIter 100;	//improved 	20-50-100

    implicitFeatureSnap false;

    explicitFeatureSnap true;

    multiRegionFeatureSnap false;

}

// Settings for the layer addition.
addLayersControls
{
    relativeSizes true;

    expansionRatio 1.2;

    firstLayerThickness 0.01;

    minThickness 0.01;

    layers
    {
        projectile
        {
            nSurfaceLayers 20;
        }
    }

    nGrow 0;

    // Advanced settings
        featureAngle 359;
        maxFaceThicknessRatio 0.5;
        nSmoothSurfaceNormals 2;
        nSmoothThickness 10;
        minMedialAxisAngle 90;
        minMedianAxisAngle 90;
        maxThicknessToMedialRatio 0.3;
        nSmoothNormals 3;
        slipFeatureAngle 80;
        nRelaxIter 5;
        nBufferCellsNoExtrude 0;
        nLayerIter 10;
        nRelaxedIter 10;
}

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

    relaxed
    {
        // Maximum non-orthogonality allowed. Set to 180 to disable.
        maxNonOrtho 75;
    }

    //minFlatness 0.5;

    // Advanced

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

// Advanced

//// Debug flags

debugFlags
(
    //mesh            // write intermediate meshes
    //intersections   // write current mesh intersections as .obj files
    //featureSeeds    // write information about explicit feature edge refinement
    //attraction      // write attraction as .obj files
    // layerInfo       // write information about layers
);


//
//// Write flags

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



mergeTolerance 1e-6;

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

corner1.jpgcorner2.jpg