[ravichaithanya]

Hi,

I am unable to get a boundary layer on the curved cylinder as attached. Where as I am able to get the boundary layer on a perfect cylindrical surface. Kindly help. The curvy surface is attached.

Below are the details of snappyHexMesh

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.x |
| \\ / 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
{

cylinder.stl
{
type triSurfaceMesh;
name riser;
}

boxA
{
type searchableBox;
min (-6 -10 -2);
max ( 20 10 12);
}
};



// Settings for the castellatedMesh generation.
castellatedMeshControls
{

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

maxLocalCells 100000;

maxGlobalCells 1400000;

minRefinementCells 0;

nCellsBetweenLevels 1;

features ();

refinementSurfaces
{
riser
{
// Surface-wise min and max refinement level
level (3 3);
regions{“*.inlet|*.outlet”{level(3,4);}}
}

}

// Resolve sharp angles on fridges
resolveFeatureAngle 30;

refinementRegions
{
boxA
{
mode inside;
levels ((1e15 3));
}

riser
{
mode distance;
levels ((0.5 4));// (0.025 3));
}
}

locationInMesh (-6 0 0);

allowFreeStandingZoneFaces true;
}



// Settings for the snapping.
snapControls
{
nSmoothPatch 3;

tolerance 4.0;

nSolveIter 30;

nRelaxIter 5;
}



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

layers
{
"riser.*"
{
nSurfaceLayers 20;
}
}

expansionRatio 1.02;

finalLayerThickness 0.4;

minThickness 0.2;

relativeSizes true;

nGrow 0;

featureAngle 30;

nRelaxIter 5;

nSmoothSurfaceNormals 1;

nSmoothNormals 3;

nSmoothThickness 10;

maxFaceThicknessRatio 0.5;

maxThicknessToMedialRatio 0.3;

minMedianAxisAngle 90;

nBufferCellsNoExtrude 0;

nLayerIter 50;
}



// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
maxNonOrtho 65;

maxBoundarySkewness 20;
maxInternalSkewness 4;

maxConcave 80;

minVol 1e-13;

minTetQuality 1e-30;

minArea -1;

minTwist 0.05;

minDeterminant 0.001;

minFaceWeight 0.05;

minVolRatio 0.01;

minTriangleTwist -1;

nSmoothScale 4;

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;


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


Thanks.

[maryCFD]

Have you tried with a lower nSurfaceLayers ? Let's say 5 for example ?