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[Other] CheckMesh vs CheckMesh -allGeometry -allTopology

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Old   December 16, 2014, 04:14
Default CheckMesh vs CheckMesh -allGeometry -allTopology
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Hello dear Foamers,
I am a new user to OpenFoam.I have been trying to simulate the flow in a Valve.The solutions diverged and so I starting debugging my setup.
To start with,I did checkMesh and everythin was 'ok' and I ran the simulation.But now I did a complete meshcheck and I see a few warnings and errors. (which might be the source of divergence)
I have attached the checkMesh -allGeometry -allTopology output below.

From the forum I could understand that concave cells and faces are not necessarily a threat to the convergence.
These cells and faces are unfortunately spread all over the Valve.Cells with small determinant,warped faces happen to be the other errors.
I will attach the pics of these faces and cells,as well as a slice of my mesh.
I don't know if the pics give as much clarity as I wanted.
I will provide more info if needed.

Kindly help me.Any tips and hints will be of great help.Thanks.

Code:
CHECKMESH -allGeometry -allTopology
Create time

Create polyMesh for time = 0

Enabling all (cell, face, edge, point) topology checks.

Enabling all geometry checks.

Time = 0

Mesh stats
    points:           5800847
    faces:            16111264
    internal faces:   15551508
    cells:            5172099
    faces per cell:   6.12184
    boundary patches: 5
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     4634186
    prisms:        150126
    wedges:        0
    pyramids:      0
    tet wedges:    1817
    tetrahedra:    8
    polyhedra:     385962
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            4   33452
            5   22367
            6   76411
            7   69622
            8   19837
            9   93654
           10   1421
           11   396
           12   50423
           13   48
           14   56
           15   16255
           16   4
           17   13
           18   1576
           20   3
           21   361
           24   63

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Topological cell zip-up check OK.
    Face-face connectivity OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
                   Patch    Faces   Points                  Surface topology Bounding box
                leftWall        0        0                        ok (empty)
            defaultFaces        0        0                        ok (empty)
             Valve_Inlet    22153    28444  ok (non-closed singly connected) (0.574884 -0.0725724 -0.0726628) (0.575 0.0725739 0.0726582)
            Valve_Outlet     7132     9634  ok (non-closed singly connected) (-1.175 -0.0725353 -0.0726304) (-1.17454 0.072542 0.0726303)
              Valve_Wall   530471   576275  ok (non-closed singly connected) (-1.175 -0.101373 -0.120015) (0.575 0.101373 0.0901)

Checking geometry...
    Overall domain bounding box (-1.175 -0.101373 -0.120015) (0.575 0.101373 0.0901)
    Mesh (non-empty, non-wedge) directions (1 1 1)
    Mesh (non-empty) directions (1 1 1)
    Boundary openness (2.72347e-15 1.09433e-15 6.58078e-15) OK.
    Max cell openness = 3.31988e-15 OK.
    Max aspect ratio = 70.5339 OK.
    Minimum face area = 6.20277e-09. Maximum face area = 0.000151314.  Face area magnitudes OK.
    Min volume = 3.0642e-12. Max volume = 1.73353e-06.  Total volume = 0.0314532.  Cell volumes OK.
    Mesh non-orthogonality Max: 64.9982 average: 7.81883
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 2.15949 OK.
    Coupled point location match (average 0) OK.
    Face tets OK.
    Min/max edge length = 1.16846e-05 0.0126579 OK.
   *There are 2959 faces with concave angles between consecutive edges. Max concave angle = 79.9922 degrees.
  <<Writing 2959 faces with concave angles to set concaveFaces
    Face flatness (1 = flat, 0 = butterfly) : average = 0.99964  min = 0.64177
   *There are 63 faces with ratio between projected and actual area < 0.8
    Minimum ratio (minimum flatness, maximum warpage) = 0.64177
  <<Writing 63 warped faces to set warpedFaces
    Cell determinant (wellposedness) : minimum: 2.71366e-05 average: 7.71483
 ***Cells with small determinant (< 0.001) found, number of cells: 6182
  <<Writing 6182 under-determined cells to set underdeterminedCells
 ***Concave cells (using face planes) found, number of cells: 186108
  <<Writing 186108 concave cells to set concaveCells

Failed 2 mesh checks.

End
Attached Images
File Type: jpg Mesh_slice.jpg (64.8 KB, 106 views)
File Type: jpg ConcaveCells.jpg (95.1 KB, 117 views)
File Type: jpg ConcaveFaces.jpg (44.3 KB, 75 views)
File Type: jpg undeterminedCells.jpg (62.8 KB, 58 views)
File Type: jpg warpedFaces.jpg (31.4 KB, 45 views)
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Old   December 19, 2014, 04:08
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Anybody??!
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Old   June 25, 2019, 04:55
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Owais Shabbir
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Hi Nagesh,



Have you found any answers to your question posted some time ago. If yes, please share.


Thanks

Have a nice day
OS
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