[Fschi]

Hello,
for simulating a wallFilm I need to extrude a wallFilm-Region out of the Mesh. So I'm using the extrudeToRegionMesh to extrude one cell up from a specific patch.

To reduce errors, I just extrude from that faces of the patch, witch got no error in the checkMesh. This explains all the holes as you can see in the picture.
The extrusion works and shows no error. But my simulations keep crashing randomly.

So I checkt the wallFilm with checkMesh and it got lots of errors. More less half of the cells got errors. Does anybody see the problem?

here my extrudeToRegionDict

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.x                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      extrudeToRegionMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

region          wallFilmRegion;

faceZones
(
	Spiegel_gesamt
);

oneD            false;

sampleMode      nearestPatchFace;

extrudeModel    linearNormal;

nLayers         1;

expansionRatio  1;

adaptMesh       yes; // apply mapped to both regions

linearNormalCoeffs
{
    thickness       0.001;
}

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

and here the checkMesh of the wallFilm

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.1                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 4.1
Exec   : checkMesh -region wallFilmRegion -allGeometry
Date   : Jan 24 2017
Time   : 17:23:07
Host   : xxx
PID    : 8104
Case   : /home/xxx/OpenFOAM/xxx-4.1/run/xxx
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh wallFilmRegion for time = 0

Enabling all geometry checks.

Time = 0

Mesh stats
    points:           354608
    internal points:  0
    faces:            659448
    internal faces:   330348
    cells:            160462
    faces per cell:   6.168413705
    boundary patches: 6
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     138040
    prisms:        17
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     22405
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            7   17973
            8   4242
            9   176
           10   14

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
  <<Found 153 neighbouring cells with multiple inbetween faces.
    Upper triangular ordering OK.
  <<Writing 314 unordered faces to set upperTriangularFace
    Face vertices OK.
   *Number of regions: 2
    The mesh has multiple regions which are not connected by any face.
  <<Writing region information to "0/cellToRegion"
  <<Writing region 0 with 160461 cells to cellSet region0
  <<Writing region 1 with 1 cells to cellSet region1

Checking patch topology for multiply connected surfaces...
                   Patch    Faces   Points                  Surface topology Bounding box
      mirror     2060     4093  ok (non-closed singly connected) (0.402795985 -0.9105368379 0.6481965009) (0.5288577768 -0.700843902 0.8179396867)
    car_Cutouterregion_newRegion     2082     4191  ok (non-closed singly connected) (0.06962297855 -0.7902702784 0.5988849637) (1.170454581 -0.4992275597 1.124585467)
     car_waterbox      182      366  ok (non-closed singly connected) (0.2352044028 -0.6506873849 0.6534346571) (0.260206109 -0.4996037967 0.6699567872)
           mirrorregion     3852     7685  ok (non-closed singly connected) (0.06967354176 -0.7897288375 0.5995095276) (1.170298736 -0.4996226921 1.123717336)
      mirror_top   160462   177342  ok (non-closed singly connected) (0.06973170497 -0.90966179 0.5988849637) (1.170454581 -0.4992406158 1.123860619)
    region0_to_wallFilmRegion   160462   177266  ok (non-closed singly connected) (0.06962297855 -0.9106137155 0.5991719738) (1.170391815 -0.4992275597 1.124585467)

Checking geometry...
    Overall domain bounding box (0.06962297855 -0.9106137155 0.5988849637) (1.170454581 -0.4992275597 1.124585467)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (2.730353862e-16 6.672305077e-15 3.04608472e-15) OK.
    Max cell openness = 3.135045759e-16 OK.
    Max aspect ratio = 5.09943786 OK.
    Minimum face area = 5.48453015e-08. Maximum face area = 2.162097278e-05.  Face area magnitudes OK.
    Min volume = 1.652464516e-10. Max volume = 1.41881011e-08.  Total volume = 0.0006743907694.  Cell volumes OK.
    Mesh non-orthogonality Max: 77.68685768 average: 5.576440163
   *Number of severely non-orthogonal (> 70 degrees) faces: 2.
    Non-orthogonality check OK.
  <<Writing 2 non-orthogonal faces to set nonOrthoFaces
 ***Error in face pyramids: 2 faces are incorrectly oriented.
  <<Writing 2 faces with incorrect orientation to set wrongOrientedFaces
 ***Max skewness = 4.304619898, 1 highly skew faces detected which may impair the quality of the results
  <<Writing 1 skew faces to set skewFaces
    Coupled point location match (average 0) OK.
 ***Error in face tets: 14 faces with low quality or negative volume decomposition tets.
  <<Writing 11 faces with low quality or negative volume decomposition tets to set lowQualityTetFaces
    Min/max edge length = 3.109156781e-05 0.006218326334 OK.
   *There are 157 faces with concave angles between consecutive edges. Max concave angle = 66.283654 degrees.
  <<Writing 157 faces with concave angles to set concaveFaces
    Face flatness (1 = flat, 0 = butterfly) : min = 0.7741734554  average = 0.9995777193
   *There are 6 faces with ratio between projected and actual area < 0.8
    Minimum ratio (minimum flatness, maximum warpage) = 0.7741734554
  <<Writing 6 warped faces to set warpedFaces
    Cell determinant (wellposedness) : minimum: 0 average: 0.02587134173
 ***Cells with small determinant (< 0.001) found, number of cells: 113816
  <<Writing 113816 under-determined cells to set underdeterminedCells
 ***Concave cells (using face planes) found, number of cells: 2000
  <<Writing 2000 concave cells to set concaveCells
    Face interpolation weight : minimum: 0.001803501669 average: 0.4519226856
 ***Faces with small interpolation weight (< 0.05) found, number of faces: 1
  <<Writing 1 faces with low interpolation weights to set lowWeightFaces
    Face volume ratio : minimum: 0.05516921194 average: 0.8065510945
    Face volume ratio check OK.

Failed 6 mesh checks.

End

Thanks in advance for your help!