[waves2Foam] Floating point exception (core dumped)

Anna.Mozhgani · November 14, 2016, 06:38

Dear foamers,
I am trying to model flap type energy converter with waveDyMFoam. I have compiled waves2foam with interDyMFoam. The result of the flume without the object is accurate enough, but when I try to use toposet and model the flap, after 5 second the model will crash. The torbulance model is RNGk-e and the solver of mesh motion is SBRStress. Here is the error of the solution. I should mention that although I have tried other motion solver like the sixDoF, the models crashed with the same error mentioned below:

PIMPLE: iteration 1

Restraint rotationDamper: moment (-0 -0 -2.00821)
6-DoF rigid body motion
Centre of rotation: (12.05 -0.215 0.325)
Centre of mass: (12.0051 -0.183706 0.325)
Orientation: (0.571574 -0.820551 0 0.820551 0.571574 0 0 0 1)
Linear velocity: (-0 -0 -0)
Angular velocity: (0 0 20.0823)
GAMGPCG: Solving for cellDisplacementx, Initial residual = 2.56915e-06, Final residual = 7.92807e-10, No Iterations 3
GAMGPCG: Solving for cellDisplacementy, Initial residual = 3.03896e-06, Final residual = 7.94894e-10, No Iterations 3
Execution time for mesh.update() = 0.79 s
GAMGPCG: Solving for pcorr, Initial residual = 1, Final residual = 4.93688e-06, No Iterations 8
time step continuity errors : sum local = 6.35764e-21, global = -7.4619e-22, cumulative = 1.68694e-09
smoothSolver: Solving for alpha.water, Initial residual = 3.87094e-05, Final residual = 3.49342e-10, No Iterations 1
Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.05447
Applying the previous iteration compression flux
MULES: Correcting alpha.water
MULES: Correcting alpha.water
MULES: Correcting alpha.water
Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.05447
Relaxing time: 0.04 s
GAMG: Solving for p_rgh, Initial residual = 0.0057705, Final residual = 6198.45, No Iterations 1000
time step continuity errors : sum local = 5.13619e-08, global = -1.03811e-08, cumulative = -8.69414e-09
GAMGPCG: Solving for p_rgh, Initial residual = 0.0095837, Final residual = 0.00877046, No Iterations 21
time step continuity errors : sum local = 2.74105e-06, global = 7.10528e-07, cumulative = 7.01834e-07
smoothSolver: Solving for epsilon, Initial residual = 0.999999, Final residual = 9.75297e-07, No Iterations 262
bounding epsilon, min: -1.51368e+10 max: 4.17942e+10 average: 3.02666e+06
smoothSolver: Solving for k, Initial residual = 1, Final residual = 7.44357e-07, No Iterations 21
bounding k, min: -1.0804e+10 max: 2.61728e+10 average: 219925
ExecutionTime = 63.63 s ClockTime = 63 s

Interface Courant Number mean: 0.000144247 max: 230.538
Courant Number mean: 0.00166072 max: 230.538
deltaT = 1.95952e-14
--> FOAM Warning :
From function Time:

perator++()
in file db/Time/Time.C at line 1061
Increased the timePrecision from 12 to 13 to distinguish between timeNames at time 5.32114
Time = 5.321144579059

PIMPLE: iteration 1

Restraint rotationDamper: moment (-0 -0 -2.00825)
6-DoF rigid body motion
Centre of rotation: (12.05 -0.215 0.325)
Centre of mass: (12.0051 -0.183706 0.325)
Orientation: (0.571574 -0.820551 0 0.820551 0.571574 0 0 0 1)
Linear velocity: (-0 -0 -0)
Angular velocity: (0 0 20.0973)
GAMGPCG: Solving for cellDisplacementx, Initial residual = 1.8826e-05, Final residual = 2.214e-09, No Iterations 3
GAMGPCG: Solving for cellDisplacementy, Initial residual = 2.07089e-05, Final residual = 2.22303e-09, No Iterations 3
Execution time for mesh.update() = 0.78 s
GAMGPCG: Solving for pcorr, Initial residual = 1, Final residual = 72.5415, No Iterations 101
time step continuity errors : sum local = 2.14545e-05, global = 6.35655e-10, cumulative = 7.02469e-07
smoothSolver: Solving for alpha.water, Initial residual = 0.000124578, Final residual = 5.5699e-12, No Iterations 2
Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.81175
Applying the previous iteration compression flux
MULES: Correcting alpha.water
MULES: Correcting alpha.water
MULES: Correcting alpha.water
Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.75933
Relaxing time: 0.05 s
#0 Foam::error:

rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/opt/openfoam240/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#3 Foam::GAMGSolver::scale(Foam::Field<double>&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const at ??:?
#4 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const at ??:?
#5 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
#6 Foam::fvMatrix<double>::solveSegregated(Foam::dict ionary const&) at ??:?
#7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:?
#8 main at ??:?
#9 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#10 ? at ??:?
Floating point exception (core dumped)

I appreciate your kindness in advance.
Anna

anishtain4 · November 14, 2016, 12:39

I'm not sure about your setup but your epsilon is blowing up (it gets bounded at a very high value, not sure if it's physically possible in your case or not?)
Also your max Courant number is 230! which is quiet high. looking at the mean courant number, it seems you are having a burst like error somewhere in your domain.
Usually this sort of errors are originated at boundary, set the writeIntervals short and watch your solution to see where the velocity is going crazy and what is blowing your case.

alexeym · November 14, 2016, 14:50

@Anna

Look at

Code:

GAMG: Solving for p_rgh, Initial residual = 0.0057705, Final residual = 6198.45, No Iterations 1000

solution diverges (final residual is greater than initial, 1000 is default maxIter value, so linear system solver stops without reaching convergence). k-epsilon diverges as a consequence.

Also

Code:

Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.05447

maximum value is way too high.

Since your mesh is dynamic, start by changing GAMG to PCG for solution of p_rgh. Do you check convergence? What is your convergence criteria (keyword is residualControl)?

Anna.Mozhgani · November 20, 2016, 05:59

Thanks for your reply
I have made the changes mentioned in the previous post.
I have modeled two different files, one of which is sixDoF, and the other one is SBRStress. Unfortunately both of them have stopped (sixDoF at and SBRStress at time step) with the same error as below:

t time 2.0547
Time = 2.0547026732024589179559370677452534437179565

PIMPLE: iteration 1

Restraint rotationDamper: moment (-0 -0 2.06432e+32)
6-DoF rigid body motion
Centre of rotation: (12.05 -0.215 0.325)
Centre of mass: (12.0501 -0.16025 0.325)
Orientation: (0.999999 0.00130702 0 -0.00130702 0.999999 0 0 0 1)
Linear velocity: (0 0 0)
Angular velocity: (0 0 -2.06424e+31)
Execution time for mesh.update() = 0.23 s
DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 9.23109e-09, No Iterations 126
time step continuity errors : sum local = 4.95352e-17, global = 2.17919e-18, cumulative = -6.84875e+07
smoothSolver: Solving for alpha.water, Initial residual = 9.28435e-06, Final residual = 1.00122e-13, No Iterations 1
Phase-1 volume fraction = 0.482205 Min(alpha.water) = 0 Max(alpha.water) = 1.00218
Applying the previous iteration compression flux
MULES: Correcting alpha.water
MULES: Correcting alpha.water
MULES: Correcting alpha.water
Phase-1 volume fraction = 0.482205 Min(alpha.water) = 0 Max(alpha.water) = 1.00218
Relaxing time: 0.06 s
DICPCG: Solving for p_rgh, Initial residual = 0.46364, Final residual = 0.000315111, No Iterations 13
time step continuity errors : sum local = 5.76792e-05, global = 4.76312e-05, cumulative = -6.84875e+07
DICPCG: Solving for p_rgh, Initial residual = 8.08681e-17, Final residual = 8.08681e-17, No Iterations 0
time step continuity errors : sum local = 3.57226e+93, global = -2.35428e+77, cumulative = -2.35428e+77
#0 Foam::error:

rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/opt/openfoam240/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#3 Foam::multiply(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:

perator*<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5 Foam::incompressible::RASModels::RNGkEpsilon::corr ect() at ??:?
#6 main at ??:?
#7 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#8 ? at ??:?
Floating point exception (core dumped)

I cant solve that.

alexeym · November 21, 2016, 04:44

Your simulation is still diverging:

Code:

Restraint rotationDamper: moment (-0 -0 2.06432e+32)
6-DoF rigid body motion
...
Angular velocity: (0 0 -2.06424e+31)
Execution time for mesh.update() = 0.23 s
...
time step continuity errors : sum local = 4.95352e-17, global = 2.17919e-18, cumulative = -6.84875e+07

Why it is diverging? Nobody knows, there could be LOTS of reasons.

Post you case description and files.

November 14, 2016, 06:38	Floating point exception (core dumped)	#1
Anna.Mozhgani New Member Anna Join Date: Jan 2016 Posts: 21 Rep Power: 10	Dear foamers, I am trying to model flap type energy converter with waveDyMFoam. I have compiled waves2foam with interDyMFoam. The result of the flume without the object is accurate enough, but when I try to use toposet and model the flap, after 5 second the model will crash. The torbulance model is RNGk-e and the solver of mesh motion is SBRStress. Here is the error of the solution. I should mention that although I have tried other motion solver like the sixDoF, the models crashed with the same error mentioned below: PIMPLE: iteration 1 Restraint rotationDamper: moment (-0 -0 -2.00821) 6-DoF rigid body motion Centre of rotation: (12.05 -0.215 0.325) Centre of mass: (12.0051 -0.183706 0.325) Orientation: (0.571574 -0.820551 0 0.820551 0.571574 0 0 0 1) Linear velocity: (-0 -0 -0) Angular velocity: (0 0 20.0823) GAMGPCG: Solving for cellDisplacementx, Initial residual = 2.56915e-06, Final residual = 7.92807e-10, No Iterations 3 GAMGPCG: Solving for cellDisplacementy, Initial residual = 3.03896e-06, Final residual = 7.94894e-10, No Iterations 3 Execution time for mesh.update() = 0.79 s GAMGPCG: Solving for pcorr, Initial residual = 1, Final residual = 4.93688e-06, No Iterations 8 time step continuity errors : sum local = 6.35764e-21, global = -7.4619e-22, cumulative = 1.68694e-09 smoothSolver: Solving for alpha.water, Initial residual = 3.87094e-05, Final residual = 3.49342e-10, No Iterations 1 Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.05447 Applying the previous iteration compression flux MULES: Correcting alpha.water MULES: Correcting alpha.water MULES: Correcting alpha.water Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.05447 Relaxing time: 0.04 s GAMG: Solving for p_rgh, Initial residual = 0.0057705, Final residual = 6198.45, No Iterations 1000 time step continuity errors : sum local = 5.13619e-08, global = -1.03811e-08, cumulative = -8.69414e-09 GAMGPCG: Solving for p_rgh, Initial residual = 0.0095837, Final residual = 0.00877046, No Iterations 21 time step continuity errors : sum local = 2.74105e-06, global = 7.10528e-07, cumulative = 7.01834e-07 smoothSolver: Solving for epsilon, Initial residual = 0.999999, Final residual = 9.75297e-07, No Iterations 262 bounding epsilon, min: -1.51368e+10 max: 4.17942e+10 average: 3.02666e+06 smoothSolver: Solving for k, Initial residual = 1, Final residual = 7.44357e-07, No Iterations 21 bounding k, min: -1.0804e+10 max: 2.61728e+10 average: 219925 ExecutionTime = 63.63 s ClockTime = 63 s Interface Courant Number mean: 0.000144247 max: 230.538 Courant Number mean: 0.00166072 max: 230.538 deltaT = 1.95952e-14 --> FOAM Warning : From function Time:perator++() in file db/Time/Time.C at line 1061 Increased the timePrecision from 12 to 13 to distinguish between timeNames at time 5.32114 Time = 5.321144579059 PIMPLE: iteration 1 Restraint rotationDamper: moment (-0 -0 -2.00825) 6-DoF rigid body motion Centre of rotation: (12.05 -0.215 0.325) Centre of mass: (12.0051 -0.183706 0.325) Orientation: (0.571574 -0.820551 0 0.820551 0.571574 0 0 0 1) Linear velocity: (-0 -0 -0) Angular velocity: (0 0 20.0973) GAMGPCG: Solving for cellDisplacementx, Initial residual = 1.8826e-05, Final residual = 2.214e-09, No Iterations 3 GAMGPCG: Solving for cellDisplacementy, Initial residual = 2.07089e-05, Final residual = 2.22303e-09, No Iterations 3 Execution time for mesh.update() = 0.78 s GAMGPCG: Solving for pcorr, Initial residual = 1, Final residual = 72.5415, No Iterations 101 time step continuity errors : sum local = 2.14545e-05, global = 6.35655e-10, cumulative = 7.02469e-07 smoothSolver: Solving for alpha.water, Initial residual = 0.000124578, Final residual = 5.5699e-12, No Iterations 2 Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.81175 Applying the previous iteration compression flux MULES: Correcting alpha.water MULES: Correcting alpha.water MULES: Correcting alpha.water Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.75933 Relaxing time: 0.05 s #0 Foam::error:rintStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/opt/openfoam240/platforms/linuxGccDPOpt/lib/libOpenFOAM.so" #3 Foam::GAMGSolver::scale(Foam::Field<double>&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const at ??:? #4 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const at ??:? #5 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:? #6 Foam::fvMatrix<double>::solveSegregated(Foam::dict ionary const&) at ??:? #7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:? #8 main at ??:? #9 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6" #10 ? at ??:? Floating point exception (core dumped) I appreciate your kindness in advance. Anna

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November 14, 2016, 12:39		#2
anishtain4 Senior Member Mahdi Hosseinali Join Date: Apr 2009 Location: NB, Canada Posts: 273 Rep Power: 18	I'm not sure about your setup but your epsilon is blowing up (it gets bounded at a very high value, not sure if it's physically possible in your case or not?) Also your max Courant number is 230! which is quiet high. looking at the mean courant number, it seems you are having a burst like error somewhere in your domain. Usually this sort of errors are originated at boundary, set the writeIntervals short and watch your solution to see where the velocity is going crazy and what is blowing your case.

November 14, 2016, 14:50		#3
alexeym Senior Member Alexey Matveichev Join Date: Aug 2011 Location: Nancy, France Posts: 1,930 Rep Power: 38	@Anna Look at Code: GAMG: Solving for p_rgh, Initial residual = 0.0057705, Final residual = 6198.45, No Iterations 1000 solution diverges (final residual is greater than initial, 1000 is default maxIter value, so linear system solver stops without reaching convergence). k-epsilon diverges as a consequence. Also Code: Phase-1 volume fraction = 0.402051 Min(alpha.water) = 0 Max(alpha.water) = 1.05447 maximum value is way too high. Since your mesh is dynamic, start by changing GAMG to PCG for solution of p_rgh. Do you check convergence? What is your convergence criteria (keyword is residualControl)?

November 20, 2016, 05:59		#4
Anna.Mozhgani New Member Anna Join Date: Jan 2016 Posts: 21 Rep Power: 10	Thanks for your reply I have made the changes mentioned in the previous post. I have modeled two different files, one of which is sixDoF, and the other one is SBRStress. Unfortunately both of them have stopped (sixDoF at and SBRStress at time step) with the same error as below: t time 2.0547 Time = 2.0547026732024589179559370677452534437179565 PIMPLE: iteration 1 Restraint rotationDamper: moment (-0 -0 2.06432e+32) 6-DoF rigid body motion Centre of rotation: (12.05 -0.215 0.325) Centre of mass: (12.0501 -0.16025 0.325) Orientation: (0.999999 0.00130702 0 -0.00130702 0.999999 0 0 0 1) Linear velocity: (0 0 0) Angular velocity: (0 0 -2.06424e+31) Execution time for mesh.update() = 0.23 s DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 9.23109e-09, No Iterations 126 time step continuity errors : sum local = 4.95352e-17, global = 2.17919e-18, cumulative = -6.84875e+07 smoothSolver: Solving for alpha.water, Initial residual = 9.28435e-06, Final residual = 1.00122e-13, No Iterations 1 Phase-1 volume fraction = 0.482205 Min(alpha.water) = 0 Max(alpha.water) = 1.00218 Applying the previous iteration compression flux MULES: Correcting alpha.water MULES: Correcting alpha.water MULES: Correcting alpha.water Phase-1 volume fraction = 0.482205 Min(alpha.water) = 0 Max(alpha.water) = 1.00218 Relaxing time: 0.06 s DICPCG: Solving for p_rgh, Initial residual = 0.46364, Final residual = 0.000315111, No Iterations 13 time step continuity errors : sum local = 5.76792e-05, global = 4.76312e-05, cumulative = -6.84875e+07 DICPCG: Solving for p_rgh, Initial residual = 8.08681e-17, Final residual = 8.08681e-17, No Iterations 0 time step continuity errors : sum local = 3.57226e+93, global = -2.35428e+77, cumulative = -2.35428e+77 #0 Foam::error:rintStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/opt/openfoam240/platforms/linuxGccDPOpt/lib/libOpenFOAM.so" #3 Foam::multiply(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:? #4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator*<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? #5 Foam::incompressible::RASModels::RNGkEpsilon::corr ect() at ??:? #6 main at ??:? #7 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6" #8 ? at ??:? Floating point exception (core dumped) I cant solve that.

November 21, 2016, 04:44		#5
alexeym Senior Member Alexey Matveichev Join Date: Aug 2011 Location: Nancy, France Posts: 1,930 Rep Power: 38	Your simulation is still diverging: Code: Restraint rotationDamper: moment (-0 -0 2.06432e+32) 6-DoF rigid body motion ... Angular velocity: (0 0 -2.06424e+31) Execution time for mesh.update() = 0.23 s ... time step continuity errors : sum local = 4.95352e-17, global = 2.17919e-18, cumulative = -6.84875e+07 Why it is diverging? Nobody knows, there could be LOTS of reasons. Post you case description and files.