[jr33]

pisoFoam runs fine until t=0.448 sec.
After that it diverges and crashes with following error:

Time = 0.44865

Courant Number mean: 0.0346229 max: 2.25125
GAMG:  Solving for Ux, Initial residual = 0.0021901, Final residual = 8.33515e-10, No Iterations 7
GAMG:  Solving for Uy, Initial residual = 0.00282035, Final residual = 6.47015e-10, No Iterations 10
GAMG:  Solving for Uz, Initial residual = 0.00343254, Final residual = 5.81644e-10, No Iterations 8
GAMG:  Solving for p, Initial residual = 0.00599169, Final residual = 9.90127e-10, No Iterations 23
GAMG:  Solving for p, Initial residual = 0.00258563, Final residual = 9.61956e-10, No Iterations 19
GAMG:  Solving for p, Initial residual = 0.000292086, Final residual = 6.42802e-10, No Iterations 14
time step continuity errors : sum local = 1.74226e-13, global = 4.33102e-14, cumulative = 1.06683e-11
GAMG:  Solving for p, Initial residual = 0.000725654, Final residual = 8.53172e-10, No Iterations 19
GAMG:  Solving for p, Initial residual = 0.000331136, Final residual = 9.20399e-10, No Iterations 14
GAMG:  Solving for p, Initial residual = 4.45138e-05, Final residual = 7.34497e-10, No Iterations 11
time step continuity errors : sum local = 1.99139e-13, global = 1.92587e-14, cumulative = 1.06875e-11
GAMG:  Solving for p, Initial residual = 0.000184586, Final residual = 8.57881e-10, No Iterations 13
GAMG:  Solving for p, Initial residual = 4.75742e-05, Final residual = 9.46137e-10, No Iterations 11
GAMG:  Solving for p, Initial residual = 6.96925e-06, Final residual = 5.26146e-10, No Iterations 9
time step continuity errors : sum local = 1.42648e-13, global = -7.47356e-15, cumulative = 1.06801e-11
GAMG:  Solving for p, Initial residual = 6.69644e-05, Final residual = 8.2169e-10, No Iterations 13
GAMG:  Solving for p, Initial residual = 1.7527e-05, Final residual = 6.28005e-10, No Iterations 10
GAMG:  Solving for p, Initial residual = 2.47075e-06, Final residual = 9.4613e-10, No Iterations 8
time step continuity errors : sum local = 2.56509e-13, global = -1.55041e-14, cumulative = 1.06645e-11
ExecutionTime = 16316.8 s  ClockTime = 16319 s

Time = 0.4487

Courant Number mean: 0.0346816 max: 2.40047
GAMG:  Solving for Ux, Initial residual = 0.00230011, Final residual = 8.51017e-10, No Iterations 50
GAMG:  Solving for Uy, Initial residual = 0.00294039, Final residual = 9.44201e-10, No Iterations 44
GAMG:  Solving for Uz, Initial residual = 0.00345345, Final residual = 9.30589e-10, No Iterations 37
GAMG:  Solving for p, Initial residual = 0.00685504, Final residual = 9.21598e-10, No Iterations 24
GAMG:  Solving for p, Initial residual = 0.00292084, Final residual = 8.05039e-10, No Iterations 19
GAMG:  Solving for p, Initial residual = 0.000342391, Final residual = 7.3001e-10, No Iterations 15
time step continuity errors : sum local = 1.98285e-13, global = -4.52974e-14, cumulative = 1.06193e-11
GAMG:  Solving for p, Initial residual = 0.000871317, Final residual = 7.51135e-10, No Iterations 20
GAMG:  Solving for p, Initial residual = 0.000449259, Final residual = 8.33107e-10, No Iterations 14
GAMG:  Solving for p, Initial residual = 5.69199e-05, Final residual = 8.8222e-10, No Iterations 12
time step continuity errors : sum local = 2.39695e-13, global = 7.09848e-14, cumulative = 1.06902e-11
GAMG:  Solving for p, Initial residual = 0.000201523, Final residual = 9.68937e-10, No Iterations 15
GAMG:  Solving for p, Initial residual = 5.71848e-05, Final residual = 6.92029e-10, No Iterations 12
GAMG:  Solving for p, Initial residual = 8.31359e-06, Final residual = 4.91838e-10, No Iterations 10
time step continuity errors : sum local = 1.33629e-13, global = 6.47104e-15, cumulative = 1.06967e-11
GAMG:  Solving for p, Initial residual = 8.53963e-05, Final residual = 5.8034e-10, No Iterations 14
GAMG:  Solving for p, Initial residual = 2.4869e-05, Final residual = 9.15113e-10, No Iterations 10
GAMG:  Solving for p, Initial residual = 2.8086e-06, Final residual = 5.25217e-10, No Iterations 9
time step continuity errors : sum local = 1.42697e-13, global = -6.84406e-15, cumulative = 1.06899e-11
ExecutionTime = 16320.8 s  ClockTime = 16323 s

Time = 0.44875

Courant Number mean: 0.0347408 max: 2.57326


 #0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#2  Uninterpreted: 
#3  Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#4  Foam::GAMGSolver::solveCoarsestLevel(Foam::Field<double>&, Foam::Field<double> const&) const in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#5  Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMatrix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#6  Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#7  
 in "/opt/openfoam221/platforms/linuxGccDPOpt/bin/pisoFoam"
#8  
 in "/opt/openfoam221/platforms/linuxGccDPOpt/bin/pisoFoam"
#9  
 in "/opt/openfoam221/platforms/linuxGccDPOpt/bin/pisoFoam"
#10  
 in "/opt/openfoam221/platforms/linuxGccDPOpt/bin/pisoFoam"
#11  __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#12  
 in "/opt/openfoam221/platforms/linuxGccDPOpt/bin/pisoFoam"
pisoFoamcheckMesh

Check Mesh details:

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

Create polyMesh for time = 0

Time = 0

Mesh stats
    points:           14939
    faces:            141770
    internal faces:   128226
    cells:            67499
    faces per cell:   4
    boundary patches: 3
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     0
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    67499
    polyhedra:     0

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                  
    patch0              1088     591      ok (non-closed singly connected)  
    patch1              1072     585      ok (non-closed singly connected)  
    patch2              11384    5786     ok (non-closed singly connected)  

Checking geometry...
    Overall domain bounding box (-0.003668 -0.004318 -0.039265) (0.003663 0.004173 0.039411)
    Mesh (non-empty, non-wedge) directions (1 1 1)
    Mesh (non-empty) directions (1 1 1)
    Boundary openness (3.58681e-18 -5.3928e-17 4.29723e-17) OK.
    Max cell openness = 1.47362e-16 OK.
    Max aspect ratio = 8.23769 OK.
    Minimum face area = 1.8095e-10. Maximum face area = 2.23531e-06.  Face area magnitudes OK.
    Min volume = 1.335e-15. Max volume = 7.98174e-10.  Total volume = 1.84215e-06.  Cell volumes OK.
    Mesh non-orthogonality Max: 76.1503 average: 15.438
   *Number of severely non-orthogonal faces: 3.
    Non-orthogonality check OK.
  <<Writing 3 non-orthogonal faces to set nonOrthoFaces
    Face pyramids OK.
    Max skewness = 0.862973 OK.
    Coupled point location match (average 0) OK.

Mesh OK.

End

I am trying to find out how to get rid of above errors, I can run another case successfully with my case settings, as well this case until 0.44 sec.
I know my mesh is not that great. I am wondering by keeping the above mesh, how I can run the simulation successfully.
Alternatively, is anyway I can debug?

Best
jay

[jr33]

Hi Foamers, after searching many threads, I realized that improving mesh is the best solution for my problem. The new minimum volume in the mesh is approximately close to 1E-15. still not better, Now, I can run my simulation for 0.89 seconds. I wanted to do it for 1 sec. In conclusion, I guess the mesh quality is the key to resolve above errors.