CFD Online Discussion Forums - [Commercial meshers] Failed 1 mesh checks

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Failed 1 mesh checks

Hello everybody,

I want to simulate the flow around a sphere. For that, I created the mesh in Gambit which looks quite good to me. Then I converted the mesh with fluent3DMeshToFoam with OpenFOAM 1.7.0.
By using checkMesh, I got the following message which I can't interpret:

Code:

Create time



Create polyMesh for time = 0



Time = 0



Mesh stats

    points:           138112

    faces:            400500

    internal faces:   387000

    cells:            131250

    boundary patches: 4

    point zones:      0

    face zones:       1

    cell zones:       1



Overall number of cells of each type:

    hexahedra:     131142

    prisms:        0

    wedges:        0

    pyramids:      0

    tet wedges:    0

    tetrahedra:    0

    polyhedra:     108



Checking topology...

    Boundary definition OK.

    Point usage OK.

  <<Found 27 neighbouring cells with multiple inbetween faces.

    Upper triangular ordering OK.

  <<Writing 54 unordered faces to set upperTriangularFace

    Face vertices OK.

    Number of regions: 1 (OK).



Checking patch topology for multiply connected surfaces ...

    Patch               Faces    Points   Surface topology                  

    outlet              625      676      ok (non-closed singly connected)  

    rest                8500     8600     ok (non-closed singly connected)  

    cylinder            3750     3752     ok (closed singly connected)      

    inlet               625      676      ok (non-closed singly connected)  



Checking geometry...

    Overall domain bounding box (0 0 0) (8 2 2)

    Mesh (non-empty, non-wedge) directions (1 1 1)

    Mesh (non-empty) directions (1 1 1)

    Boundary openness (-9.45575e-17 -2.58425e-18 -7.56937e-18) OK.

 ***Open cells found, max cell openness: 0.878109, number of open cells 108

  <<Writing 108 non closed cells to set nonClosedCells

    Minumum face area = 8.6151e-05. Maximum face area = 0.0105716.  Face area magnitudes OK.

    Min volume = 1.37781e-06. Max volume = 0.000845729.  Total volume = 31.9665.  Cell volumes OK.

    Mesh non-orthogonality Max: 53.2154 average: 19.1478

    Non-orthogonality check OK.

    Face pyramids OK.

    Max skewness = 1.02786 OK.



Failed 1 mesh checks.



End

Actually I created a structured grid in Gambit, but looking at it in ParaView there are some unstructured parts after the conversion, as written above.
I also tried to import the mesh into Fluent and I got an error: Null Domain Pointer.

Does anyone have a clue?
With kind regards, Nico

try with fluentMeshToFoam
Paraview issue, is just a graphic bug.
But if you cannot import your grid in fluent, I assume there is someting wrong.
no warning while exporting your mesh from gambit?

I checked the mesh in Gambit and everything was fine, also no errror while exporting.
With fluentMeshToFoam I got the following:

Code:

Create time



Dimension of grid: 3

Number of points: 138112

Reading points

number of faces: 400500

Reading mixed faces

Reading mixed faces

Reading mixed faces

Reading mixed faces

Reading mixed faces

Number of cells: 131250

Other readCellGroupData: 2 1 200b2 1 4

Reading uniform cells

Read zone1:2 name:fluid patchTypeID:fluid

Reading zone data

Read zone1:3 name:outlet patchTypeID:pressure-outlet

Reading zone data

Read zone1:4 name:rest patchTypeID:symmetry

Reading zone data

Read zone1:5 name:cylinder patchTypeID:wall

Reading zone data

Read zone1:6 name:inlet patchTypeID:velocity-inlet

Reading zone data

Read zone1:8 name:default-interior patchTypeID:interior

Reading zone data





FINISHED LEXING





dimension of grid: 3

Creating shapes for 3-D cells





--> FOAM FATAL ERROR: 

Cannot find match for face 5.

Model: hex model face: 4(1 2 6 5) Mesh faces: 

6

(

4(4586 4610 4609 4585)

4(4609 4585 4586 4610)

4(4585 20031 20607 4586)

4(20583 4610 4586 20607)

4(20031 4585 4609 20007)

4(4610 20583 20007 4609)

)

Matched points: 8(4586 20607 20031 4585 4610 20583 20007 4609)



    From function create3DCellShape(const label cellIndex, const labelList& faceLabels, const labelListList& faces, const labelList& owner, const labelList& neighbour, const label fluentCellModelID)

    in file create3DCellShape.C at line 280.



FOAM aborting



#0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam170/lib/linux64GccDPOpt/libOpenFOAM.so"

#1  Foam::error::abort() in "/opt/openfoam170/lib/linux64GccDPOpt/libOpenFOAM.so"

#2  

 in "/opt/openfoam170/applications/bin/linux64GccDPOpt/fluentMeshToFoam"

#3  

 in "/opt/openfoam170/applications/bin/linux64GccDPOpt/fluentMeshToFoam"

#4  __libc_start_main in "/lib/libc.so.6"

#5  

 in "/opt/openfoam170/applications/bin/linux64GccDPOpt/fluentMeshToFoam"

Aborted

Just to check: create another mesh with Gambit (full tetra, or tetra-hexcore)
export, and load it into Foam.
Check if you still have problem.
PS: Something is weird with those 108 polyhedra, since Gambit isn t able to create Polyhedra

Thank you max, for your quick replies. I checked a new mesh, just with a few more cells and it worked. I still dont know why this problems appears but now I can do my simulations on it.