CFD Online Discussion Forums - Error message decoding

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Error message decoding

Hi all,
I often come accross those nice error message (like below) our dear OpenFoam send me when solver crashes, but I'm never able to "decode" them.
Can someone help me to understand what OF is trying to tell me?

Code:

Phase-1 volume fraction = 0.923319  Min(alpha.water) = -5.8983e-07  Max(alpha.water) = 1.05862

[3] #0  Foam::error::printStack(Foam::Ostream&) at ??:?

[3] #1  Foam::sigFpe::sigHandler(int) at ??:?

[3] #2  ? in "/lib/x86_64-linux-gnu/libc.so.6"

[3] #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 ??:?

[3] #4  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::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const at ??:?

[3] #5  Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?

[3] #6  Foam::fvMatrix<double>::solveSegregated(Foam::dictionary const&) at ??:?

[3] #7  Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:?

[3] #8  ? at ??:?

[3] #9  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"

[3] #10  ? at ??:?

[CALCUL:07902] *** Process received signal ***

[CALCUL:07902] Signal: Floating point exception (8)

[CALCUL:07902] Signal code:  (-6)

[CALCUL:07902] Failing at address: 0x3e900001ede

[CALCUL:07902] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x36d40) [0x7fb490ad9d40]

[CALCUL:07902] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x39) [0x7fb490ad9cc9]

[CALCUL:07902] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x36d40) [0x7fb490ad9d40]

[CALCUL:07902] [ 3] /opt/openfoam240/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZNK4Foam10GAMGSolver5scaleERNS_5FieldIdEES3_RKNS_9lduMatrixERKNS_10FieldFieldIS1_dEERKNS_8UPtrListIKNS_17lduInterfaceFieldEEERKS2_h+0xbe) [0x7fb491c2eb7e]

[CALCUL:07902] [ 4] /opt/openfoam240/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZNK4Foam10GAMGSolver6VcycleERKNS_7PtrListINS_9lduMatrix8smootherEEERNS_5FieldIdEERKS8_S9_S9_S9_S9_S9_RNS1_IS8_EESD_h+0xfe9) [0x7fb491c321e9]

[CALCUL:07902] [ 5] /opt/openfoam240/platforms/linux64GccDPOpt/lib/libOpenFOAM.so(_ZNK4Foam10GAMGSolver5solveERNS_5FieldIdEERKS2_h+0x4ae) [0x7fb491c3400e]

[CALCUL:07902] [ 6] /opt/openfoam240/platforms/linux64GccDPOpt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE15solveSegregatedERKNS_10dictionaryE+0x132) [0x7fb494443c32]

[CALCUL:07902] [ 7] LTSInterDyMFoam(_ZN4Foam8fvMatrixIdE5solveERKNS_10dictionaryE+0x108) [0x47eac8]

[CALCUL:07902] [ 8] LTSInterDyMFoam() [0x432ac9]

[CALCUL:07902] [ 9] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7fb490ac4ec5]

[CALCUL:07902] [10] LTSInterDyMFoam() [0x4372da]

[CALCUL:07902] *** End of error message ***

Any translator???
Thank you for your help
Regards

Hi there;

I guess there is something going on wrong within your code. Basically if ur dividing by 0 anywhere or so. the best way is to go step by step in such a case. Change small portions of code from the original code and re run at every step. So you can know where the error is. But I think it would be nice if you could also mention the solver you are using and case for others to understand.

I am not familiar with other debuggers but I guess they can also help you out such as GCC etc.

Hi!
Thank you for your help. My case study is flow around a ship hull. The solver I'm using is home-made. I've actually mixed together interDyMFoam and LTSInterFoam in order to find the dynamic equilibrium of a ship at a certain speed.
I just started form interDyMFoam and copy-paste part of the code of LTSInterFOAM. This seems to work pretty well, motion looks nice and smooth and forces on hull doesn't look crazy. However initial residual of pressure are always 1 (I think it's because the mesh is changinging at every iteration).

I can send you the code if interested.

Hi jojosaxo,

I do not know if it will be of any help but I am doing a simulation with a dynamic mesh (my mesh also changes at each iterations) and my initial residual of pressure is not always 1 ! I am not a professional of OpenFoam by any mean, I am just stating what I see from my simulations.

On the other hand, the kind of messages you are stating in your initial post did happen to me all the time since I began to use OpenFoam. What I have learned is that usually I do not need to decode those crash messages because they are not the reason the crash happen. I usually look at the few iterations BEFORE the crash, and really often I can see that something went wrong before the actual crash. Of course, the behaviour propagates through some iterations until the solver actually crashes.

Can you print the messages from the iterations before the crash one ?

Hi jojosaxo,

what is about your alpha.water?
Could your problem be a mathematical error in cause of a strange alpha.water?

Quote:

Originally Posted by jojosaxo (Post 548458)

Code:

Phase-1 volume fraction = 0.923319  Min(alpha.water) = -5.8983e-07  Max(alpha.water) = 1.05862

[3] #0  Foam::error::printStack(Foam::Ostream&) at ??:?

...

As far as I know alpha.water, or alpha.vapour should be between 0 and 1.
I think OF just wanted to say that.

regards
Alex

Quote:

Originally Posted by jojosaxo (Post 548511)

Hi, jojosaxo!
can you send me the code. very interesting