[Hiroshiman]

Hi,
I'm meshing a complex 3D geometry using snappyHex mesh for transient flow simulation using pimpleFoam. When I run checkMesh on my case I get :

Time = 0

Mesh stats
    points:           241926
    faces:            585183
    internal faces:   523327
    cells:            179081
    faces per cell:   6.18999
    boundary patches: 7
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     128793
    prisms:        9069
    wedges:        0
    pyramids:      0
    tet wedges:    925
    tetrahedra:    30
    polyhedra:     40264
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            4   12216
            5   6431
            6   6864
            7   386
            8   415
            9   6591
           10   139
           11   134
           12   3677
           13   43
           14   40
           15   3021
           16   7
           17   7
           18   258
           20   1
           21   30
           24   4

Checking topology...
    Boundary definition OK.
    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
                     il1      398      475  ok (non-closed singly connected)
            defaultFaces    52012    66767  ok (non-closed singly connected)
                     ren      180      293  ok (non-closed singly connected)
                   inlet     5979     6306  ok (non-closed singly connected)
                     il2     1317     1469  ok (non-closed singly connected)
                     il3      933     1032  ok (non-closed singly connected)
                     il4     1037     1148  ok (non-closed singly connected)

Checking geometry...
    Overall domain bounding box (-0.0738687 -0.236453 0.724997) (0.0819296 -0.12425 1.085)
    Mesh (non-empty, non-wedge) directions (1 1 1)
    Mesh (non-empty) directions (1 1 1)
    Boundary openness (5.27378e-16 -5.96184e-16 3.35583e-17) OK.
    Max cell openness = 3.42542e-16 OK.
    Max aspect ratio = 9.17275 OK.
    Minimum face area = 4.24086e-09. Maximum face area = 1.61588e-05.  Face area magnitudes OK.
    Min volume = 1.24757e-12. Max volume = 5.47073e-08.  Total volume = 0.000215698.  Cell volumes OK.
    Mesh non-orthogonality Max: 64.62 average: 13.9596
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 2.96129 OK.
    Coupled point location match (average 0) OK.

Mesh OK.

End

After approximately 50% on my run the simulation diverges and when I look at the last available results I can spot a bad looking cell (see picture).
crash_U_mesh.jpg
It's a crop of the outlet (visible on the left) on which a pressure is applied using codedFixValue.

Are there anything appart from refining the mesh to avoid this ? Which error parameter in the snappyHexMeshDict should be modified ? Usually checkmesh is talkative enough to give hints...

Thanks,

Florian