simpleFoam error  "Floating point exception"
1 Attachment(s)
Hi everyone,
I'm running into an error running simpleFoam (this problem also happens with icoFoam). Casefile can be found at the following address: https://drive.google.com/file/d/0B5R...it?usp=sharing I'm getting the error pasted below. The log file also reveals that the solution is diverging which I suspect why this is happening. checkMesh looks good, boundary conditions appear sensible. Any ideas would be much appreciated! :confused: #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #2 in "/lib/x86_64linuxgnu/libc.so.6" #3 Foam::divide(Foam::Field<double>&, double const&, Foam::UList<double> const&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #4 at simpleFoam.C:0 #5 in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/simpleFoam" #6 __libc_start_main in "/lib/x86_64linuxgnu/libc.so.6" #7 in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/simpleFoam" Floating point exception (core dumped) 
1 Attachment(s)
Hi,
Obviously you've got diverging solution. Look at all those 1001 in log file, it is default maximum number of iteration of the matrix solver after which it will give up even it doesn't get the solution within given tolerances. I'm not quite get from the case files what you are trying to do but I've attached archive with the settings that can bear your setup. But the velocities in the narrow part of the mesh are around 4 km/s so I guess it doesn't make much sense. I've attached only archive of the system folder as I've made no changes in other folders. 
Thanks alexeym!
It's running for me up to timestep 19.8 so obviously this is a big improvement. Basically, I'm just trying to measure permeability across this mesh by sampling pressure difference and flux through the two planes that are my inlets and outlets. Perhaps reducing the velocity bc at the inlet will reduce the absolute velocity in the narrow section but I imagine relatively speaking, the velocity would still be this high. Would reducing the initial velocity amount help the solution converge? 
Well,
You can try to estimate velocity in the narrow part from crosssection areas ratio. As you are trying to run simulation in laminar case, you should also estimate Reynolds number to see if it is really so. And answering your question: yes, it will help. 
error:time step continuty errors increasing and diverged
Quote:
Code:
#0 Foam::error::printStack(Foam::Ostream&) in "/home/user5/OpenFOAM/OpenFOAM2.1.0/platforms/linux64Gcc45DPOpt/lib/libOpenFOAM.so" Code:
ddtSchemes Code:
Create time 
your first step : time step already diverge, you can have a check about your mesh and your boundary condition settings

i run checkMesh and it shows:
Create polyMesh for time = 0 Time = 0 Mesh stats points: 644339 faces: 6657993 internal faces: 6626605 cells: 3261204 faces per cell: 4.07353 boundary patches: 4 point zones: 0 face zones: 1 cell zones: 2 Overall number of cells of each type: hexahedra: 100740 prisms: 3984 wedges: 0 pyramids: 34318 tet wedges: 0 tetrahedra: 3122162 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 blade 24146 21942 ok (closed singly connected) inlet 1841 966 ok (nonclosed singly connected) outlet 1841 966 ok (nonclosed singly connected) symmetry 3560 3649 ok (nonclosed singly connected) Checking geometry... Overall domain bounding box (12.7106 6.66098 12.7139) (12.7102 27.7695 12.7057) Mesh (nonempty, nonwedge) directions (1 1 1) Mesh (nonempty) directions (1 1 1) Boundary openness (2.3031e15 3.09845e16 5.48772e16) OK. Max cell openness = 1.07338e15 OK. Max aspect ratio = 30.0527 OK. Minimum face area = 6.8698e07. Maximum face area = 0.772395. Face area magnitudes OK. Min volume = 3.21357e10. Max volume = 0.154152. Total volume = 17466.7. Cell volumes OK. Mesh nonorthogonality Max: 70.2416 average: 19.945 *Number of severely nonorthogonal (> 70 degrees) faces: 3. Nonorthogonality check OK. <<Writing 3 nonorthogonal faces to set nonOrthoFaces Face pyramids OK. Max skewness = 3.90819 OK. Coupled point location match (average 0) OK. Mesh OK. how ablout the mesh quality? if bad,does the problem lie in the volume range or the 3 nonorthogonal faces or something eles? 
Quote:
Code:
#0 Foam::error::printStack(Foam::Ostream&) in "/home/user5/OpenFOAM/OpenFOAM2.1.0/platforms/linux64Gcc45DPOpt/lib/libOpenFOAM.so" 
It seems the log file didnt upload, I am so confused. I can only cut the part where error happens.
Time = 75 smoothSolver: Solving for Ux, Initial residual = 0.0602954, Final residual = 0.00373723, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.0653118, Final residual = 0.00486974, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.0597028, Final residual = 0.00373956, No Iterations 2 GAMG: Solving for p, Initial residual = 9.91772e08, Final residual = 9.91772e08, No Iterations 0 time step continuity errors : sum local = 0.508126, global = 0.00403281, cumulative = 0.0725249 smoothSolver: Solving for epsilon, Initial residual = 0.111438, Final residual = 2.47159e07, No Iterations 2 smoothSolver: Solving for k, Initial residual = 0.0644941, Final residual = 0.00196909, No Iterations 2 ExecutionTime = 1101.44 s ClockTime = 1104 s Time = 76 smoothSolver: Solving for Ux, Initial residual = 0.0594781, Final residual = 0.00349262, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.060454, Final residual = 0.00433672, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.0589499, Final residual = 0.00349089, No Iterations 2 GAMG: Solving for p, Initial residual = 9.85788e08, Final residual = 9.85788e08, No Iterations 0 time step continuity errors : sum local = 0.536801, global = 0.00461372, cumulative = 0.0679112 smoothSolver: Solving for epsilon, Initial residual = 0.119377, Final residual = 1.54768e07, No Iterations 2 smoothSolver: Solving for k, Initial residual = 0.0767105, Final residual = 0.00221075, No Iterations 2 ExecutionTime = 1115.63 s ClockTime = 1118 s Time = 77 smoothSolver: Solving for Ux, Initial residual = 0.0592163, Final residual = 0.00329118, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.0563358, Final residual = 0.00385813, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.0588684, Final residual = 0.00329036, No Iterations 2 GAMG: Solving for p, Initial residual = 9.65561e08, Final residual = 9.65561e08, No Iterations 0 time step continuity errors : sum local = 0.565758, global = 0.00525311, cumulative = 0.0626581 smoothSolver: Solving for epsilon, Initial residual = 0.124077, Final residual = 9.12524e08, No Iterations 2 smoothSolver: Solving for k, Initial residual = 0.0872853, Final residual = 0.00261114, No Iterations 2 ExecutionTime = 1129.82 s ClockTime = 1133 s Time = 78 smoothSolver: Solving for Ux, Initial residual = 0.0601651, Final residual = 0.00311845, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.0534155, Final residual = 0.00342506, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.0595368, Final residual = 0.0031283, No Iterations 2 GAMG: Solving for p, Initial residual = 9.28703e08, Final residual = 9.28703e08, No Iterations 0 time step continuity errors : sum local = 0.594105, global = 0.00596336, cumulative = 0.0566947 smoothSolver: Solving for epsilon, Initial residual = 0.130123, Final residual = 5.31763e08, No Iterations 2 smoothSolver: Solving for k, Initial residual = 0.0996443, Final residual = 0.00317308, No Iterations 2 bounding k, min: 27.2023 max: 6.08394e+06 average: 47.9263 ExecutionTime = 1144.26 s ClockTime = 1147 s Time = 79 smoothSolver: Solving for Ux, Initial residual = 0.0614544, Final residual = 0.00297322, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.0514696, Final residual = 0.00306002, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.0607817, Final residual = 0.00298804, No Iterations 2 GAMG: Solving for p, Initial residual = 8.84393e08, Final residual = 8.84393e08, No Iterations 0 time step continuity errors : sum local = 0.620817, global = 0.00674595, cumulative = 0.0499488 smoothSolver: Solving for epsilon, Initial residual = 0.13737, Final residual = 2.93949e08, No Iterations 2 smoothSolver: Solving for k, Initial residual = 0.113938, Final residual = 0.00343359, No Iterations 2 bounding k, min: 216.755 max: 8.91232e+06 average: 61.9746 ExecutionTime = 1158.68 s ClockTime = 1161 s Time = 80 smoothSolver: Solving for Ux, Initial residual = 0.063004, Final residual = 0.00283814, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.0505971, Final residual = 0.00273304, No Iterations 2 smoothSolver: Solving for Uz, Initial residual = 0.0624865, Final residual = 0.0028546, No Iterations 2 GAMG: Solving for p, Initial residual = 8.29655e08, Final residual = 8.29655e08, No Iterations 0 time step continuity errors : sum local = 0.645584, global = 0.00760253, cumulative = 0.0423462 smoothSolver: Solving for epsilon, Initial residual = 0.143916, Final residual = 1.66331e08, No Iterations 2 smoothSolver: Solving for k, Initial residual = 0.127062, Final residual = 0.00356757, No Iterations 2 bounding k, min: 19.5544 max: 1.31047e+07 average: 81.9192 ExecutionTime = 1173.05 s ClockTime = 1176 s 
Floating point exception (core dumped) Immersed boundary simpleIbFoam
Hi I am using simpleIbFoam, each time I run it shows this error. The checkMesh looks ok. Can someone help with this issue :confused:? Thanks in advance !!
anamitra@anamitraHPPaviliong6NotebookPC:~/IC_Files/Empty_Domain/simpleibfoam_vg$ simpleIbFoam /**\  =========    \\ / F ield  foamextend: Open Source CFD   \\ / O peration  Version: 3.1   \\ / A nd  Web: http://www.extendproject.de   \\/ M anipulation   \**/ Build : 3.17d8e040bf53d Exec : simpleIbFoam Date : Apr 21 2015 Time : 19:30:14 Host : anamitraHPPaviliong6NotebookPC PID : 8630 CtrlDict : /home/anamitra/foam/foamextend3.1/etc/controlDict Case : /home/anamitra/IC_Files/Empty_Domain/simpleibfoam_vg nProcs : 1 SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE). // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create mesh for time = 0 Reading field p Reading field U Reading/calculating face flux field phi Selecting incompressible transport model Newtonian Selecting RAS turbulence model kOmegaSST External flow Number of IB cells: 76 kOmegaSSTCoeffs { alphaK1 0.85034; alphaK2 1; alphaOmega1 0.5; alphaOmega2 0.85616; gamma1 0.5532; gamma2 0.4403; beta1 0.075; beta2 0.0828; betaStar 0.09; a1 0.31; c1 10; } Create immersed boundary cell mask Create immersed boundary face mask Found immersed boundary patch 0 named ibsimplevg Starting time loop Time = 1 DILUPBiCG: Solving for Ux, Initial residual = 0.357069, Final residual = 0.000767327, No Iterations 2 DILUPBiCG: Solving for Uy, Initial residual = 0.999927, Final residual = 0.00105008, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 0.285562, Final residual = 0.000466337, No Iterations 2 DICPCG: Solving for p, Initial residual = 0.984177, Final residual = 0.0909034, No Iterations 85 time step continuity errors : sum local = 0.175394, global = 0.00155391, cumulative = 0.00155391 Floating point exception (core dumped) anamitra@anamitraHPPaviliong6NotebookPC:~/IC_Files/Empty_Domain/simpleibfoam_vg$ 
Anamitra:
It looks like you need to double check your BCs and ICs. Also, it's taking a lot of iterations to converge your pressure, you might consider a different numerical method if your BC/ICs are okay. 
Hi,
Thanks for the reply!! Could you suggest what changes are possible in the boundary conditions, I am still looking for it. I am not very sure what factors can cause the floating point exception. I am solving a case of external flow around a cuboid (with Immersed boundary) placed around the centre of the flow domain. Pressure looks like this: internalField nonuniform List<scalar> 256000 (long list found from mapping fields) boundaryField { ibsimplevg { type immersedBoundary; refValue uniform 0; refGradient uniform 0; fixesValue no; setDeadCellValue yes; deadCellValue 0; value nonuniform 0(); } inlet { type zeroGradient; } outlet { type zeroGradient; } sides { type symmetryPlane; } wall_plate { type zeroGradient; } top { type zeroGradient; } } 
1 Attachment(s)
Hi Foamer
I have an error with running rhoPorousSimpleFoam in my simple model. Code:
#0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam221/platforms/linuxGccDPOpt/lib/libOpenFOAM.so" 
All times are GMT 4. The time now is 12:46. 