CFD Online Discussion Forums - Gas dispersion in air error message

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Thanks Bruno!!

will do it! and i am using Openfoam version 2.2.0.

Hi Brunos,

When i try to modify the reactingFoam model with my mesh i get the following error.

[COLOR="Red"]
Create time

Create mesh for time = 0

Reading g
Creating reaction model

Selecting combustion model PaSR<psiChemistryCombustion>
Selecting chemistry type
{
chemistrySolver ode;
chemistryThermo psi;
}

Selecting thermodynamics package
{
type hePsiThermo;
mixture reactingMixture;
transport sutherland;
thermo janaf;
energy sensibleEnthalpy;
equationOfState perfectGas;
specie specie;
}

Selecting chemistryReader foamChemistryReader
#0 Foam::error::printStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 Uninterpreted:
#3 Foam::fvPatchField<double>::operator/=(Foam::fvPatchField<double> const&) at ??:?
...
.
.
.
.
.
.
at ??:?
#26 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#27
at ??:?
Floating point exception (core dumped)

Where is the problem??? What should i change?

Quote:

Originally Posted by redhoax (Post 410868)

Hi. I'm running a reactingFoam case. kOmegaSST for turbulence, CH4 dispersion in air. no chemistry, no combustion. I get an error message that I'm not capable of interpreting, and was hoping maybe one of you guys were able to, or even if you could tip me on how to learn it. Anyways, here's the error:

Code:

#0  Foam::error::printStack(Foam::Ostream&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"

#1  Foam::sigFpe::sigHandler(int) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"

#2  Uninterpreted: 

#3  Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"

#4  void Foam::divide<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#5  Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#6  Foam::compressible::RASModels::kOmegaSST::F2() const in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#7  Foam::compressible::RASModels::kOmegaSST::kOmegaSST(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::basicThermo const&, Foam::word const&, Foam::word const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#8  Foam::compressible::RASModel::adddictionaryConstructorToTable<Foam::compressible::RASModels::kOmegaSST>::New(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::basicThermo const&, Foam::word const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#9  Foam::compressible::RASModel::New(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::basicThermo const&, Foam::word const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#10  Foam::compressible::turbulenceModel::addturbulenceModelConstructorToTable<Foam::compressible::RASModel>::NewturbulenceModel(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::basicThermo const&, Foam::word const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleRASModels.so"

#11  Foam::compressible::turbulenceModel::New(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::basicThermo const&, Foam::word const&) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/lib/libcompressibleTurbulenceModel.so"

#12  main in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/bin/reactingFoam"

#13  __libc_start_main in "/lib/libc.so.6"

#14  Foam::UOPstream::write(char) in "/home/user/OpenFOAM/OpenFOAM-2.1.x/platforms/linuxGccDPOpt/bin/reactingFoam"

Thank you in advance.

Hi redhoax,
to understand the problem I tried my geometry in rhoSimpleFOAM. when i encountered this i changed my underrelaxation factors of rho and p. the simulation was running fine.

But when i run the case in reactingFOAM the problem is there. I am wondering is there any way i can change parameters ?(as i did for rhoSimpleFOAM) so i can run my simulations.

Hi Lasse,

Quote:

Originally Posted by redhoax (Post 421094)

I updated the case and shared it with you on Dropbox. At the moment I'm experimenting with different variables, such as wind inlet velocity and fuel rate, and trying to decide how to make the platform geometry.

Lasse

I have finally managed to look into the folder you shared with me! And I noticed that your geometry has the "outlet" patch embedded into the "frontAndBack" patch! Therefore, the case is not properly defined, since the "outlet" patch is not present in the mesh :(

By the way, you mentioned in the share message, that when you activate the gravity, that the solver/solution would diverge. There are two possibilities:

The missing "outlet" patch is critical. Without it, it's a wonder that the solver didn't crash sooner! ;)
The initial internal fields for "epsilon" and "k" and very low. Try starting with higher values, because (if I'm not mistaken) you're dealing with a compressible fluid solver and the pressure is absolute, not relative. Therefore, k-Epsilon values can be rather high and a good initial field is critical for the solution to not diverge!

Best regards,
Bruno

wow, i'm so sorry. i discovered that myself the same day(just after) i updated the dropbox case and corrected it. mustve forgot to upload the corrected one. I will however test higher k-Epsilon values. i'll update that blockmeshdict asap

Hello!:-)

i updated the case. the solution is not diverging now, however...

i'm struggling with what seems to me as reversed flow from the outlet patch. at both top and bottom corner along the outlet(although one is located on the top patch) patch are strong velocity fields, oppositely directed. at the top is inflow, bottom outflow. see attached pictures for visual on how ridiculous my situation is. All taken at t=1s:
This is full mesh 3D: Attachment 21515
This is top and outlet only. The blue field on the top patch is -23m/s in negative X-direction...Attachment 21516
Finally a picture of my outlet patch. How did it come to this? :pAttachment 21517

sine the issue arised after extracting the outlet patch from the top patch, and the problem shows on top and outlet patch, these boundary conditions are what i've looked into and played with the most. i made a table with an overview of my current conditions in the 0-folder. Attachment 21518 (This image is in the dropbox folder in full size. Also the full case is updated.)

with this new issue i feel like i'm stumbling around in the dark looking for the solution in tutorials while not able to rationalize where it comes from, but i continue to look into it of course! And thanks a lot for all help you have provided me already. It's really generous :)

Regards,
Lasse

Update: i've tried to eliminate possible sources of error, but in failing to locate the root cause i have now made the case a laminar one with a viscosity a 1000 times higher than normal. still, after just t=1s the entire domain is showing unrealistic velocities..

Full domain from side: Attachment 21541

Air inlet only: Attachment 21542

So the question is, what is causing the domain to obtain these velocity fields.. I'm in pursuit. Dropbox updated accordingly.

Lasse

Quote:

Originally Posted by redhoax (Post 421094)

Can you share the case files with me too..... my email is alexleekh@singnet.com.sg Thanks