CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[snappyHexMesh] Strange striated surface mesh

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 9, 2019, 08:44
Default Strange striated surface mesh
  #1
Member
 
Andrew
Join Date: Mar 2018
Posts: 82
Rep Power: 8
Astan is on a distinguished road
Hi guys i'm facing with a strage problem in the surface mesh done in snappyhex mesh.
It is something related to the way in which snappy cuts the cells during the snap process, it is clearly seen in the following two screenshots.
I link also the snappyHexMesh dictionary.

Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5                                     |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

    castellatedMesh false;
    snap false;
    addLayers true;
     geometry
    {
        test964.stl
        {
            type triSurfaceMesh;
            name test964;
            appendRegionName false;
        }

        RuotaAnt.stl
        {
            type triSurfaceMesh;
            name RuotaAnt;
            appendRegionName false;
        }

        RuotaPost.stl
        {
            type triSurfaceMesh;
            name RuotaPost;
            appendRegionName false;
        }

        box
        {
            type searchableBox;
            min ( -4.0 -2.0 -2.0 );
            max ( 4.0 2.0 2.0 );
        }

        box0
        {
            type searchableBox;
            min ( -2.0 -1.0 -1.0 );
            max ( 2.0 1.0 1.0 );
        }


    }

    castellatedMeshControls
    {
        features
        (
        
        {
            file "test964.eMesh";
            levels ((0.005 6)); // 0.05
            refineFeatureEdgesOnly false;
        }

        {
            file "RuotaPost.eMesh";
            levels ((0.005 5));
            refineFeatureEdgesOnly false;
        }

        {
            file "RuotaAnt.eMesh";
            levels ((0.005 5));
            refineFeatureEdgesOnly false;
        }
       
        );

        refinementSurfaces
        {
            test964
            {
                level ( 6 6 );
            }
            
            RuotaAnt
            {
                level ( 5 5 );
            }

            RuotaPost
            {
                level ( 5 5 );
            }

        }

       refinementRegions
       {
            box
            {
                mode inside;
                levels (( 1E5 1 ));
            }

            box0
            {
                mode inside;
                levels (( 1E5 3 ));
            }
        }

        locationInMesh ( 5.2159 2.2686 2.2052 );
        maxLocalCells 10000000;
        maxGlobalCells 10000000;
        minRefinementCells 0;
        nCellsBetweenLevels 6;
        resolveFeatureAngle 30.0;
        allowFreeStandingZoneFaces true;
        planarAngle 30.0;
        maxLoadUnbalance 0.1;
    }

    snapControls
    {
        nSolveIter 700;
        nSmoothPatch 5;
        tolerance 5;
        nRelaxIter 8;
        nFeatureSnapIter 10;
        implicitFeatureSnap false;
        explicitFeatureSnap true;
        multiRegionFeatureSnap false;
    }

    addLayersControls

{
        layers
        {
            test964
            {
                nSurfaceLayers 1;
            }

            RuotaAnt
            {
                nSurfaceLayers 1;
            }
            
            RuotaPost
            {
                nSurfaceLayers 1;
            }

        }

        relativeSizes false;
        expansionRatio 1;
        finalLayerThickness 0.002;	;
        minThickness 1.0E-9;
        nGrow 0;
        featureAngle 300.0;
        slipFeatureAngle 150.0; // 30
        nRelaxIter 5;
        nSmoothSurfaceNormals 1;
        nSmoothNormals 3;
        nSmoothThickness 20;
        maxFaceThicknessRatio 0.5;
        maxThicknessToMedialRatio 0.3;
        minMedialAxisAngle 90;
        nBufferCellsNoExtrude 0;
        nLayerIter 60;
        nRelaxedIter 20;
        writeVTK false;
        noErrors false;
        layerRecovery 1;
        growZoneLayers false;
        projectGrownUp 0.0;
    }



    meshQualityControls
    {
        maxNonOrtho 65.0;
        maxBoundarySkewness 20;
        maxInternalSkewness 4;
        maxConcave 80.0;
        minFlatness 0.5;
        minVol 1.0E-13;
        minTetQuality 1.0E-15;
        minArea -1.0;
        minTwist 0.02;
        minDeterminant 0.001;
        minFaceWeight 0.05;
        minVolRatio 0.01;
        minTriangleTwist -1.0;
        nSmoothScale 4;
        errorReduction 0.75;
        relaxed
        {
            maxNonOrtho 75;
        }

    }

debugFlags
(

);
writeFlags
(
      scalarLevels
      layerSets
      layerFields
);

mergeTolerance 1e-6;

// ************************************************************************* //
How could i get rid off this problem? what's wrong in your opinion?

thanks you very much for the time spent in this thread, any suggestion is welcomed.

Astan
Attached Images
File Type: jpg view2.jpg (201.5 KB, 14 views)
File Type: png view.png (43.5 KB, 8 views)
Astan is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[snappyHexMesh] SnappyHexMesh for internal Flow vishwa OpenFOAM Meshing & Mesh Conversion 24 June 27, 2016 08:54
[Gmsh] Error : Self intersecting surface mesh, computing intersections & Error : Impossible velan OpenFOAM Meshing & Mesh Conversion 3 October 22, 2015 11:05
[snappyHexMesh] No layers in a small gap bobburnquist OpenFOAM Meshing & Mesh Conversion 6 August 26, 2015 09:38
Cluster ID's not contiguous in compute-nodes domain. ??? Shogan FLUENT 1 May 28, 2014 15:03
[snappyHexMesh] Layers:problem with curvature giulio.topazio OpenFOAM Meshing & Mesh Conversion 10 August 22, 2012 09:03


All times are GMT -4. The time now is 08:10.