[a_habib]

Hello every one, I'm training on the use of snappyHexMesh and during the procedure I'm having a problem,the snappyHexMesh is not using the triSurfaces so there is no cells to remove, it types these in the terminal:
(
Not all entries in refinementSurfaces dictionary were used. The following entries were not used : 1(car.stl)
)
and
(
Not all entries in refinementRegions dictionary were used. The following entries were not used : 1(car.stl)
)
- the *.stl file where made once by SOLIDWORKS (ASCII format) and once by FreeCAD (ASCII format).
- the stl file is in the correct direction (constant/triSurface).
- the stl file is closed surface (I used surfaceCheck).
- the stl file is like this:
(( solid car
facet normal 0.991911 0.126938 0.000000
outer loop
vertex -0.026076 -0.011176 -0.033830
vertex -0.026017 -0.011637 -0.033390
.
.
.
vertex -0.025949 -0.012660 0.031710
endloop
endfacet
endsolid car))
- the stl file is in the center of the background mesh (I used paraview to make sure).
- the background mesh has the aspect ratio of 1 and an appropriate grid spacing (the stl file is much much bigger than the zero level cell.


so what to do
please help

[christos]

Hi Ahmad,

I am also new to OpenFOAM world. Can you post your snappyHexMeshDict file? Maybe during copy paste you have made an error in the geometry sub-directory of snappyHexMesh. Are you sure that the names corresponds to the .stl surfaces?

[a_habib]

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.3.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      snappyHexMeshDict;
}

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

castellatedMesh true;
snap            true;
addLayers       false;


geometry
{
    car.stl
    {
        type triSurfaceMesh;
        name cylinder;
    }

    refineBox
    {
        type searchableBox;
        min	(-0.1 -0.1 -0.1);
        max	(0.1 0.1 0.1);
    }
};



castellatedMeshControls
{

    maxLocalCells 10000000;

    maxGlobalCells 10000000;

    minRefinementCells 0;

    nCellsBetweenLevels 1;


    features
    (
    );

    refinementSurfaces
    {
        car.stl
        {
            // Surface-wise min and max refinement level
            level (4 4);
        }
    }

    resolveFeatureAngle 30;

    refinementRegions
    {
        refineBox
        {
            mode inside;
            levels ((1E15 2));
        }
        car.stl
        {
            mode distance;
            levels ((0.05 4) (0.1 3));
        }
    }


    locationInMesh (-0.19999 0.0001 0.0001);

      allowFreeStandingZoneFaces true;
}




snapControls
{
      nSmoothPatch 3;
    tolerance 1.0;
    nSolveIter 300;
    nRelaxIter 5;
        nFeatureSnapIter 10;
        implicitFeatureSnap false;
        explicitFeatureSnap true;
        multiRegionFeatureSnap true;
}



addLayersControls
{
       relativeSizes true;

  
    layers
    {
//        ""
//        {
//            nSurfaceLayers 1;
//        }
    }


    expansionRatio 1.0;

    finalLayerThickness 0.3;

    minThickness 0.25;

    nGrow 0;

    featureAngle 30;

    nRelaxIter 5;

    nSmoothSurfaceNormals 1;

    nSmoothNormals 3;

    nSmoothThickness 10;

    maxFaceThicknessRatio 0.5;

    maxThicknessToMedialRatio 0.3;


    minMedianAxisAngle 90;


    nBufferCellsNoExtrude 0;

    nLayerIter 50;

    nRelaxedIter 20;
}



meshQualityControls
{
    #include "meshQualityDict"

    relaxed
    {
 
        maxNonOrtho 75;
    }

    nSmoothScale 4;
 
    errorReduction 0.75;
}

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;


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

[christos]

Hi Ahmad

Make the following modification and tell me if it works

geometry
{
    car.stl
    {
        type triSurfaceMesh;
        name car;
    }

[a_habib]

it didn't work and I don't know where the ''cylinder'' came from,

[christos]

Hi Ahmad,

I think that your snappyHexMeshDict is not correct. For example, you haven't included anything in the features sub-dictionary. I am not sure but for your case the feature subdictionary should be sth like that:

features
(

     {
            file "car.eMesh";
            level 2; 

     }


)

Try to change the features list. If it doesn't work again, look in a proper snappyHexMeshDict (e.x look the flange snappyHexMeshDict /tutorials/mesh/snappyHexMeshDict/flange) and find the differences with your own.

[a_habib]

look at this

Reading refinement surfaces.
--> FOAM Warning : 
    From function refinementSurfaces::refinementSurfaces(..)
    in file autoHexMesh/refinementSurfaces/refinementSurfaces.C at line 226
    Reading "/home/ahmad/my_tutorials/snappyHexMesh/car_snappyHexMesh_02/system/snappyHexMeshDict.castellatedMeshControls.refinementSurfaces" from line 70 to line 70
    Not all entries in refinementSurfaces dictionary were used. The following entries were not used : 1(car.stl)
Read refinement surfaces in = 0.02 s

Reading refinement shells.
Refinement level 2 for all cells inside refineBox
--> FOAM Warning : 
    From function shellSurfaces::shellSurfaces(..)
    in file autoHexMesh/shellSurfaces/shellSurfaces.C at line 420
    Reading "/home/ahmad/my_tutorials/snappyHexMesh/car_snappyHexMesh_02/system/snappyHexMeshDict.castellatedMeshControls.refinementRegions" from line 82 to line 88
    Not all entries in refinementRegions dictionary were used. The following entries were not used : 1(car.stl)
Read refinement shells in = 0 s

[a_habib]

this is the it:

    refinementSurfaces
    {
        car
        {
            level (3 3);
        }
    }

    resolveFeatureAngle 30;



    refinementRegions
    {
        refineBox
        {
            mode inside;
            levels ((1E15 1));
        }
        car
        {
            mode distance;
            levels ((0.05 3) (0.1 2));
        }
    }

I was using car.stl and the correct is car

[christos]

That's nice man!!

I am happy you solved your problem.

Regards, Christos

[mm_FOAM]

The above posts were very helpful to me in troubleshooting my snappyHexMesh. Thanks all!