[ANacc]

Trying to chase down an error and am wondering if anyone has run into this issue before. I am simulating a 3D cylindrical fluidized bed using twoPhaseEulerFoam (parallel run using 24 processors) and have received the following stack using both the Gidaspow and SyamlalOBrien drag models:

[19] #0  Foam::error::printStack(Foam::Ostream&) in "/shared/apps/openfoam/openfoam-2.3.1/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[19] #1  Foam::sigFpe::sigHandler(int) in "/shared/apps/openfoam/openfoam-2.3.1/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[19] #2
[19]  at sigaction.c:0
[19] #3  Foam::sqrt(Foam::Field<double>&, Foam::UList<double> const&) in "/shared/apps/openfoam/openfoam-2.3.1/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
[19] #4  Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::sqrt<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) $
[19] #5  Foam::dragModels::SyamlalOBrien::CdRe() const in "/shared/apps/openfoam/openfoam-2.3.1/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libcompressibleEulerianInterfacialModels.so"
[19] #6  Foam::dragModel::K() const in "/shared/apps/openfoam/openfoam-2.3.1/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libcompressibleEulerianInterfacialModels.so"
[19] #7  Foam::RASModels::kineticTheoryModel::correct() in "/home/naccarato.a/OpenFOAM/naccarato.a-2.3.1/platforms/linux64GccDPOpt/lib/libphaseCompressibleTurbulenceModels.so"
[19] #8  Foam::twoPhaseSystem::correctTurbulence() in "/shared/apps/openfoam/openfoam-2.3.1/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libcompressibleTwoPhaseSystem.so"
[19] #9
[19]  in "/home/naccarato.a/OpenFOAM/naccarato.a-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"
[19] #10  __libc_start_main in "/lib64/libc.so.6"
[19] #11
[19]  in "/home/naccarato.a/OpenFOAM/naccarato.a-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"

The run is terminated after 2sec for Syamlal, 4sec for Gidaspow. Any thoughts or guidance are much appreciated.

[ANacc]

Some additional information:

I can get my case to run with coarser meshes. As I try to refine the mesh I see the error message. Could there be an issue caused by the cylindrical geometry I am using?

[alexeym]

Hi,

According to the log you have provided the error happens during sqrt call. SyamlalOBrien CdRe method contains bunch of sqrt calls.

Also you have mentioned that while using Gidaspov (which on btw?) your case also halts with error. Both models contain pow(Re, 0.687) and if Re is negative, FPE occurs.

Why Re is negative? Guess your solution is diverging.

And finally as you have said, you are able to run the case on coarse grid, it looks your time step is too large. Do you adjust time step? Though it would be easier if you just attach archive of your system folder (as after adjustTimeStep question, there will be nOuterCorrectors question, convergence criterion question etc).

[ANacc]

Thanks for the suggestion. The time step seems to solve the issue.

[mwaqas]

Hello Everyone

I am also using OF2.3.1 and simulating 2D fluidized bed using solver twoPhaseEulerFOAM. I am facing a similar problem as mentioned above but smaller time step is not working for me.
1) First of all I changed some parameters like diameter of particle, geometry dimension (2D sylinderical geometry), viscosity, Alphamax 0.65, and tried to run the simulation, I got the following error

[QUOTE][/#0 Foam::error:rintStack(Foam::Ostream&) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#4
in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"
#5 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#6
in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"
Floating point exception (core dumped)
]

Then I thought there might be something wrong with my changed whcih I have made. I tried to run simulation without any change in 2.3.1 tutorial, still I got the following erroe

[QUOTE][/#0 Foam::error:rintStack(Foam::Ostream&) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::tmp<Foam::Field<Foam::Vector<double> > > Foam:perator/<Foam::Vector<double> >(Foam::UList<Foam::Vector<double> > const&, Foam::UList<double> const&) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#4 Foam::interstitialInletVelocityFvPatchVectorField: :updateCoeffs() in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#5 Foam::fvMatrix<Foam::Vector<double> >::fvMatrix(Foam::GeometricField<Foam::Vector<doub le>, Foam::fvPatchField, Foam::volMesh> const&, Foam::dimensionSet const&) in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"
#6
in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"
#7 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#8
in "/home/waqas/OpenFOAM/OpenFOAM-2.3.1/platforms/linux64GccDPOpt/bin/twoPhaseEulerFoam"
Floating point exception (core dumped)
]

Can you please tell me, what is going wrong and how can I fix this error.
I received these errors after very first time step.

Regards

[ANacc]

Your error log looks different that the one I posted originally. Some more details will be helpful.

Which tutorial case are you trying to run? I'm assuming this is the case you modified (if not, let me know).

[mwaqas]

Hello ANacc

Thank you so much for your quick response. I have posted two errors.
First was produced with the modified case, and the second error was generated for openfoam default tutorial. Now my problem is resolved. Actually I was making mistake in alpha.air boundary condition. I was using inlet and outlet for alpha.air as fixedValue =0

Anyhow I am simulating 2D fluidized bed for dp=728 micron with k-epsilon model using twoPhaseEulerFoam, this work is for my master thesis. May be I need your help in future if I face any other problem. Thank you

Regards

[mwaqas]

Hello ANacc

I am using OF2.3.1 for the simulation of fluidized bed: I am facing a problem in mass conservation. WHen I use following command to check the mass flow rate of air and particles at inlet and outlet, it does not conserve.

patchIntegrate phi.air inlet
patchIntegrate phi.air outlet
patchIntegrate phi.particles inlet
patchIntegrate phi.particles outlet

I am using following boundary condition for 0/alpha.particles/inlet, outlet (fixedValue = uniform 0) in order to make sure zero entrainment of solid particles with air. Also the superficial velocity is too low for entrainment. The above mentioned commands are showing zero mass flow of particles out of the geometry with air. So for air inlet and outlet mass flow should be equal but it is showing almost 5% increase in air mass flow. Have you tried these commands or have any idea about it. Thank you

Regards