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Problems creating OpenFOAM mesh with Netgen

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Old   March 22, 2014, 12:53
Default Problems creating OpenFOAM mesh with Netgen
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I am using Netgen to mesh my 3D model for OpenFOAM, as OpenFOAM does not support triangular mesh types I went into Netgens meshing options [Mesh] [Meshing Options] and changed the setting to be "Quad Dominated", when I generate the mesh and try to export it as "OpenFOAM v 1.5+ Format" I get an error and nothing gets written out:
http://gyazo.com/539c45e12fb3271418d3c4f07fedf284
However, if I leave the default settings in Netgen and generate a mesh using the pre-defined triangular mesh type, it exports fine and generates the polymesh file. Why is this happening and how do I fix the problem please?
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Old   March 22, 2014, 18:03
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I used the default settings and generated the polyMesh. I now have a problem setting boundary conditions for my empty patches. If I set them as shown and run checkMesh, I get a Mesh Okay message returned but my solver does not work as there is not an empty type defined:
Code:
2 
( 
    walls 
    { 
        type            patch; 
        physicalType    patch; 
        nFaces          843; 
        startFace       7136; 
    } 
    frontAndBack 
    { 
        type            patch; 
        physicalType    patch; 
        nFaces          2549; 
        startFace       7979; 
    } 
)
If I change my boundary file as shown:
Code:
2 
( 
    walls 
    { 
        type            wall; 
        nFaces          843; 
        startFace       7136; 
    } 
    frontAndBack 
    { 
        type            empty; 
        inGroups        1(empty); 
        nFaces          2549; 
        startFace       7979; 
    } 
)
I get the following error when running checkMesh:
Code:
Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
    points:           1701
    faces:            10528
    internal faces:   7136
    cells:            4416
    faces per cell:   4
    boundary patches: 2
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     0
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    4416
    polyhedra:     0

Checking topology...
    Boundary definition OK.
 ***Total number of faces on empty patches is not divisible by the number of cells in the mesh. Hence this mesh is not 1D or 2D.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
    Patch               Faces    Points   Surface topology                  
    walls               843      639      ok (non-closed singly connected)  
    frontAndBack        2549     1494     ok (non-closed singly connected)  

Checking geometry...
    Overall domain bounding box (0 0.078921 -0) (1 18.8288 45.8885)
    Mesh (non-empty, non-wedge) directions (0 1 1)
    Mesh (non-empty) directions (0 1 1)
 ***Number of edges not aligned with or perpendicular to non-empty directions: 3715
  <<Writing 1676 points on non-aligned edges to set nonAlignedEdges
    Boundary openness (1.76312e-17 -1.4093e-18 -1.62669e-18) OK.
    Max cell openness = 1.10581e-16 OK.
    Max aspect ratio = 4.45814 OK.
    Minimum face area = 0.0850357. Maximum face area = 1.59048.  Face area magnitudes OK.
    Min volume = 0.0116823. Max volume = 0.53016.  Total volume = 392.397.  Cell volumes OK.
    Mesh non-orthogonality Max: 57.2026 average: 23.7279
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 0.656776 OK.
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.

End

Last edited by sur4j; March 22, 2014 at 19:26.
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