HelloWorld 
May 11, 2010 06:41 
Problem with skew faces in simpleFoam...
Hello Foamers,
I'm running in a problem with simpleFoam here which is caused by highly skewed faces in my mesh after snappyHexMesh. But since this is my second model ever I'm simulating on I just can't figure out how to fix the problem.
so here's the detailed description of my problem:
I have an STLmodel of a car which I'm meshing with snappyHexMesh. After meshing I've run the checkMeshutility on it (see the result below). As shown in the checkMeshreport I have to deal with some highly skewed faces. Please note that I had a number about 190 highly skewed faces after my first run, so I increased the number of iterations in the snappyHexMeshDict for smoothing and solving to approx. 100, which actually took loads of time to mesh (about 9.5 hours only for meshing, is that normal?). As I said the result is shown below.
So I decided to give the simulation a try because the results after meshing for 2nd looked better than the results from the first time (Max skewness > 7 there). I first ran the potentialFoam solver on the case to calculate the potential flow (in parallel with writepoption) and started to run the simpleFoamsolver. It begins quite fine and the residuals also look good but after the it produces an error which I don't understand what it wants to tell me (see logoutput below) and the simulation stops.
So, for now, I am a little confused on how to get that problem solved, because I don't really understand what's happening. Should I further increase the number of iterations in solving and smoothing in snappyHexMesh?
Any ideas on this issue would be greatly appreciated. Thanks in advance, regards
Yasar
checkMeshreport:
Quote:
Create time
Create polyMesh for time = 0
Time = 0
Mesh stats
points: 7789696
faces: 19507504
internal faces: 17853716
cells: 5889441
boundary patches: 6
point zones: 0
face zones: 0
cell zones: 0
Overall number of cells of each type:
hexahedra: 5181607
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 707834
Checking topology...
Boundary definition 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
frontAndBack 32256 32786 ok (nonclosed singly connected)
inlet 9216 9409 ok (nonclosed singly connected)
outlet 9216 9409 ok (nonclosed singly connected)
lowerWall 39202 40974 ok (nonclosed singly connected)
upperWall 16128 16393 ok (nonclosed singly connected)
body_ascii 1547770 1616044 multiply connected (shared edge)
<<Writing 6 conflicting points to set nonManifoldPoints
Checking geometry...
Overall domain bounding box (7 4 2.19444e05) (7 4 8)
Mesh (nonempty, nonwedge) directions (1 1 1)
Mesh (nonempty) directions (1 1 1)
Boundary openness (7.1503e16 1.75172e15 2.08081e14) OK.
Max cell openness = 3.4668e16 OK.
Max aspect ratio = 13.7502 OK.
Minumum face area = 1.17455e08. Maximum face area = 0.00694556. Face area magnitudes OK.
Min volume = 1.09199e11. Max volume = 0.000578843. Total volume = 895.944. Cell volumes OK.
Mesh nonorthogonality Max: 65.5369 average: 11.097
Nonorthogonality check OK.
Face pyramids OK.
***Max skewness = 5.00251, 28 highly skew faces detected which may impair the quality of the results
<<Writing 28 skew faces to set skewFaces
Failed 1 mesh checks.
End

simpleFoamreport:
Quote:
Time = 1
DILUPBiCG: Solving for Ux, Initial residual = 0.0470019, Final residual = 0.00159451, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.016735, Final residual = 0.000794285, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.00512888, Final residual = 0.000209387, No Iterations 1
GAMG: Solving for p, Initial residual = 0.533966, Final residual = 0.0521085, No Iterations 5
GAMG: Solving for p, Initial residual = 6.32435e05, Final residual = 6.1552e06, No Iterations 5
GAMG: Solving for p, Initial residual = 5.9373e06, Final residual = 4.10853e07, No Iterations 6
GAMG: Solving for p, Initial residual = 4.09881e07, Final residual = 7.06244e08, No Iterations 4
time step continuity errors : sum local = 0.000203317, global = 4.61929e07, cumulative = 4.61929e07
DILUPBiCG: Solving for omega, Initial residual = 0.00155999, Final residual = 0.000146049, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 0.0113172, No Iterations 2
ExecutionTime = 52.6 s ClockTime = 52 s
Time = 2
DILUPBiCG: Solving for Ux, Initial residual = 0.149428, Final residual = 0.0113072, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.117821, Final residual = 0.0093268, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.106949, Final residual = 0.0070286, No Iterations 1
GAMG: Solving for p, Initial residual = 0.00210953, Final residual = 0.00016236, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000120218, Final residual = 7.7692e06, No Iterations 6
GAMG: Solving for p, Initial residual = 7.5233e06, Final residual = 5.19068e07, No Iterations 6
GAMG: Solving for p, Initial residual = 5.18458e07, Final residual = 8.13884e08, No Iterations 4
time step continuity errors : sum local = 8.77645e05, global = 1.32735e06, cumulative = 1.78927e06
DILUPBiCG: Solving for omega, Initial residual = 0.000656903, Final residual = 5.00807e06, No Iterations 2
DILUPBiCG: Solving for k, Initial residual = 0.0293622, Final residual = 0.00282563, No Iterations 1
ExecutionTime = 91.23 s ClockTime = 91 s
Time = 3
DILUPBiCG: Solving for Ux, Initial residual = 0.203513, Final residual = 0.014925, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.138747, Final residual = 0.0110201, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.124262, Final residual = 0.00813135, No Iterations 1
GAMG: Solving for p, Initial residual = 0.0042347, Final residual = 0.000315632, No Iterations 3
GAMG: Solving for p, Initial residual = 0.027243, Final residual = 0.00228496, No Iterations 6
GAMG: Solving for p, Initial residual = 0.000232067, Final residual = 1.93698e05, No Iterations 11
GAMG: Solving for p, Initial residual = 1.77123e05, Final residual = 1.68434e06, No Iterations 10
time step continuity errors : sum local = 0.000132953, global = 1.22741e06, cumulative = 5.61861e07
DILUPBiCG: Solving for omega, Initial residual = 0.000526977, Final residual = 5.19195e05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.0175695, Final residual = 0.0016615, No Iterations 1
ExecutionTime = 140.46 s ClockTime = 140 s
Time = 4
DILUPBiCG: Solving for Ux, Initial residual = 0.142828, Final residual = 0.0099319, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0910163, Final residual = 0.00705615, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0430176, Final residual = 0.00261685, No Iterations 1
GAMG: Solving for p, Initial residual = 0.00562449, Final residual = 0.000403218, No Iterations 4
GAMG: Solving for p, Initial residual = 0.000298234, Final residual = 2.85729e05, No Iterations 5
GAMG: Solving for p, Initial residual = 2.58226e05, Final residual = 1.77719e06, No Iterations 6
GAMG: Solving for p, Initial residual = 1.7678e06, Final residual = 1.27912e07, No Iterations 6
time step continuity errors : sum local = 0.000100083, global = 1.29687e06, cumulative = 7.35013e07
DILUPBiCG: Solving for omega, Initial residual = 0.000384138, Final residual = 3.59847e05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.0116713, Final residual = 0.00105877, No Iterations 1
ExecutionTime = 175.52 s ClockTime = 175 s
Time = 5
DILUPBiCG: Solving for Ux, Initial residual = 0.0567542, Final residual = 0.00230703, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0345311, Final residual = 0.00163081, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0136472, Final residual = 0.000531466, No Iterations 1
GAMG: Solving for p, Initial residual = 0.015898, Final residual = 0.00142227, No Iterations 4
GAMG: Solving for p, Initial residual = 0.000205296, Final residual = 1.99854e05, No Iterations 5
GAMG: Solving for p, Initial residual = 1.86487e05, Final residual = 1.28029e06, No Iterations 6
GAMG: Solving for p, Initial residual = 1.27547e06, Final residual = 9.04708e08, No Iterations 6
time step continuity errors : sum local = 8.73983e05, global = 1.17262e06, cumulative = 1.90763e06
DILUPBiCG: Solving for omega, Initial residual = 0.000272353, Final residual = 2.48687e05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.00704169, Final residual = 0.000685767, No Iterations 1
ExecutionTime = 211.96 s ClockTime = 212 s
Time = 6
DILUPBiCG: Solving for Ux, Initial residual = 0.0505934, Final residual = 0.00345681, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0418622, Final residual = 0.00363079, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0108325, Final residual = 0.000825592, No Iterations 1
GAMG: Solving for p, Initial residual = 0.00819174, Final residual = 0.000724051, No Iterations 3
GAMG: Solving for p, Initial residual = 0.000227248, Final residual = 2.16144e05, No Iterations 5
GAMG: Solving for p, Initial residual = 1.99455e05, Final residual = 1.36262e06, No Iterations 6
GAMG: Solving for p, Initial residual = 1.35665e06, Final residual = 9.11873e08, No Iterations 6
time step continuity errors : sum local = 6.61502e05, global = 1.37282e07, cumulative = 2.04491e06
DILUPBiCG: Solving for omega, Initial residual = 0.000209738, Final residual = 1.9301e05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.00470266, Final residual = 0.000436278, No Iterations 1
ExecutionTime = 245.04 s ClockTime = 245 s
Time = 7
DILUPBiCG: Solving for Ux, Initial residual = 0.0991008, Final residual = 0.00667086, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0711584, Final residual = 0.00591094, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0278779, Final residual = 0.00193497, No Iterations 1
GAMG: Solving for p, Initial residual = 0.00632294, Final residual = 0.000219981, No Iterations 2
GAMG: Solving for p, Initial residual = 0.000284016, Final residual = 1.93529e05, No Iterations 4
GAMG: Solving for p, Initial residual = 2.19301e05, Final residual = 1.57307e06, No Iterations 5
GAMG: Solving for p, Initial residual = 1.58729e06, Final residual = 1.40923e07, No Iterations 5
time step continuity errors : sum local = 3.20926e05, global = 6.85727e08, cumulative = 2.11349e06
DILUPBiCG: Solving for omega, Initial residual = 0.000179259, Final residual = 1.5832e05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.00366453, Final residual = 0.000314028, No Iterations 1
ExecutionTime = 275.36 s ClockTime = 275 s
Time = 8
DILUPBiCG: Solving for Ux, Initial residual = 0.0998382, Final residual = 0.00637505, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.0676365, Final residual = 0.00532405, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0387657, Final residual = 0.00257048, No Iterations 1
GAMG: Solving for p, Initial residual = 0.00684188, Final residual = 0.000443793, No Iterations 3
GAMG: Solving for p, Initial residual = 0.00117625, Final residual = 0.000106433, No Iterations 5
GAMG: Solving for p, Initial residual = 7.42813e05, Final residual = 4.99522e06, No Iterations 6
GAMG: Solving for p, Initial residual = 4.91373e06, Final residual = 3.37231e07, No Iterations 6
time step continuity errors : sum local = 5.60022e05, global = 3.23231e08, cumulative = 2.08116e06
DILUPBiCG: Solving for omega, Initial residual = 0.000156607, Final residual = 1.42548e05, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.00290969, Final residual = 0.000245979, No Iterations 1
ExecutionTime = 309.96 s ClockTime = 310 s
Time = 9
[10] #0 Foam::error::printStack(Foam::Ostream&) in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
[10] #1 Foam::sigFpe::sigFpeHandler(int) in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
[10] #2 ?? in "/lib64/libc.so.6"
[10] #3 Foam::LimitedScheme<Foam::Vector<double>, Foam::GammaLimiter<Foam::NVDVTVDV>, Foam::limitFuncs::null>::limiter(Foam::GeometricFi eld<F
oam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) const in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so"
[10] #4 Foam::limitedSurfaceInterpolationScheme<Foam::Vect or<double> >::weights(Foam::GeometricField<Foam::Vector<doubl e>, Foam::fvPatchField, Foam::volMesh> const&) const in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so"
[10] #5 Foam::fv::gaussConvectionScheme<Foam::Vector<doubl e> >::fvmDiv(Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> c
onst&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh>&) const in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so"
[10] #6 Foam::tmp<Foam::fvMatrix<Foam::Vector<double> > > Foam::fvm::div<Foam::Vector<double> >(Foam::GeometricField<double, Foam::fvsPatchFi
eld, Foam::surfaceMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh>&, Foam::word const&) in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/applications/bin/linux64GccDPOpt/simpleFoam"
[10] #7 Foam::tmp<Foam::fvMatrix<Foam::Vector<double> > > Foam::fvm::div<Foam::Vector<double> >(Foam::GeometricField<double, Foam::fvsPatchFi
eld, Foam::surfaceMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh>&) in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/applications/bin/linux64GccDPOpt/simpleFoam"
[10] #8 main in "/opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/applications/bin/linux64GccDPOpt/simpleFoam"
[10] #9 __libc_start_main in "/lib64/libc.so.6"
[10] #10 _start at /usr/src/packages/BUILD/glibc2.9/csu/../sysdeps/x86_64/elf/start.S:116
[ivk190:22464] *** Process received signal ***
[ivk190:22464] Signal: Floating point exception (8)
[ivk190:22464] Signal code: (6)
[ivk190:22464] Failing at address: 0x7e3000057c0
[ivk190:22464] [ 0] /lib64/libc.so.6 [0x7f96109db6e0]
[ivk190:22464] [ 1] /lib64/libc.so.6(gsignal+0x35) [0x7f96109db645]
[ivk190:22464] [ 2] /lib64/libc.so.6 [0x7f96109db6e0]
[ivk190:22464] [ 3] /opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so(_ZNK4Foam13LimitedSchemeINS_6Ve ctorIdEENS_12GammaLimiterINS_8NVDVTVDVEEENS_10limi tFuncs4nullEE7limiterERKNS_14GeometricFieldIS2_NS_ 12fvPatchFieldENS_7volMeshEEE+0x446) [0x7f9612377eb6]
[ivk190:22464] [ 4] /opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so(_ZNK4Foam33limitedSurfaceInterp olationSchemeINS_6VectorIdEEE7weightsERKNS_14Geome tricFieldIS2_NS_12fvPatchFieldENS_7volMeshEEE+0x2a ) [0x7f961235ad7a]
[ivk190:22464] [ 5] /opt1/OpenFOAM/SUSE11.1/OpenFOAM1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so(_ZNK4Foam2fv21gaussConvectionSc hemeINS_6VectorIdEEE6fvmDivERKNS_14GeometricFieldI dNS_13fvsPatchFieldENS_11surfaceMeshEEERNS5_IS3_NS _12fvPatchFieldENS_7volMeshEEE+0x59) [0x7f96126382c9]
[ivk190:22464] [ 6] simpleFoam [0x440b51]
[ivk190:22464] [ 7] simpleFoam [0x440d7c]
[ivk190:22464] [ 8] simpleFoam [0x41546f]
[ivk190:22464] [ 9] /lib64/libc.so.6(__libc_start_main+0xe6) [0x7f96109c7586]
[ivk190:22464] [10] simpleFoam [0x414899]
[ivk190:22464] *** End of error message ***
[ivk189][[63242,1],6][btl_tcp_frag.c:216:mca_btl_tcp_frag_recv] mca_btl_tcp_frag_recv: readv failed: Connection reset by peer (104)
[ivk191][[63242,1],14][btl_tcp_frag.c:216:mca_btl_tcp_frag_recv] mca_btl_tcp_frag_recv: readv failed: Connection reset by peer (104)

mpirun noticed that process rank 10 with PID 22464 on node 129.69.127.90 exited on signal 8 (Floating point exception).


