[fawzi]

Hello everyone,

When running the shockTube tutorial with 100 cells in the x-direction, the solutions runs without any problem but when I change the number of cells to 1000, I get the following error:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

Create time

Create mesh for time = 0

PIMPLE: No convergence criteria found

PIMPLE: No corrector convergence criteria found

Calculations will do 2 corrections

PIMPLE: Operating solver in transient mode with 2 outer correctors

Reading thermophysical properties

Selecting thermodynamics package

{

type hePsiThermo;

mixture pureMixture;

transport const;

thermo hConst;

equationOfState perfectGas;

specie specie;

energy sensibleInternalEnergy;

}

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

#1 Foam::sigFpe::sigHandler(int) at ??:?

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

#3 Foam::heThermo<Foam::psiThermo, Foam::pureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam::perfectGas<Foa m::specie> >, Foam::sensibleInternalEnergy> > > >::heThermo(Foam::fvMesh const&, Foam::word const&) at ??:?

#4 Foam::fluidThermo::addfvMeshConstructorToTable<Foa m::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam::perfectGas<Foa m::specie> >, Foam::sensibleInternalEnergy> > > > >::New(Foam::fvMesh const&, Foam::word const&) at ??:?

#5 Foam::autoPtr<Foam::fluidThermo> Foam::basicThermo::New<Foam::fluidThermo>(Foam::fv Mesh const&, Foam::word const&) at ??:?

#6 Foam::fluidThermo::New(Foam::fvMesh const&, Foam::word const&) at ??:?

#7 ? in "/opt/openfoam7/platforms/linux64GccDPInt32Opt/bin/rhoPimpleFoam"

#8 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"

#9 ? in "/opt/openfoam7/platforms/linux64GccDPInt32Opt/bin/rhoPimpleFoam"

Floating point exception (core dumped)

*Note: I included the full case file and error log file

Thank you in advance

[Krao]

Hi, I don't know whether I could help you with the error but for sure, 'No convergence criteria found' is not an error. This means OpenFOAM is informing you to add something like below in your PIMPLE loop of fvSolutions, just in case if you require. It is not mandatory,

residualControl
{
U 1e-5;
p 1e-5;
"(k|epsilon|omega)" 1e-5;
}

When your residuals reach those values the simulation will automatically stop.

[fawzi]

Originally Posted by Krao

Hi, I don't know whether I could help you with the error but for sure, 'No convergence criteria found' is not an error. This means OpenFOAM is informing you to add something like below in your PIMPLE loop of fvSolutions, just in case if you require. It is not mandatory,



When your residuals reach those values the simulation will automatically stop.

Dear Krao,

Thank you for your reply. When I read online, I found the suggestion that you mentioned and I implemented it but got the same warning let’s call it. Is that because the tolerances that I set for the p, u etc are small?

Finally, even if I get that notification, I should expect to load the results in a post-processing package without a problem, correct?

Regards,

Fawzi

[Bazinga]

Yes, you can run pimpleFoam without these convergence criteria and get results.

The PIMPLE convergence criteria are only applied if you also use outer loops. Then, you run outer loops until the residual at the first iteration of solving a matrix is below the threshold defined.

[fawzi]

Thanks a lot, things make much more sense now!

[fawzi]

Originally Posted by Bazinga

Yes, you can run pimpleFoam without these convergence criteria and get results.

The PIMPLE convergence criteria are only applied if you also use outer loops. Then, you run outer loops until the residual at the first iteration of solving a matrix is below the threshold defined.

Hello again,


I ran the simulation again and no solution results (files) were generated. I have a feeling it has to do with the part of the code that I attached above indicated by "#1" etc.


Thanks in advance

[fawzi]

From reading online, it seems like the issue is related to a boundary condition that is causing nonphysical flow phenomena. What is confusing me is that the tutorial that I am following seems to work just fine for the tutor (on YouTube).





I have attached the 0 folder incase this can help.


Thank you very much


(sorry, I have just very recently started learning how to use OpenFOAM.

[Bazinga]

Well if the error in post #1 still exists you will not get any results, because the simulation crashes.

I am not familiar with this tutorial, so someone else might help out, but I recommend to upload the whole case + log file when solving.

[sss.nitp]

PIMPLE: No convergence criteria found


PIMPLE: Operating solver in PISO mode

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting turbulence model type RAS
Selecting RAS turbulence model kEpsilon
RAS
{
RASModel kEpsilon;
turbulence on;
printCoeffs on;
Cmu 0.09;
C1 1.44;
C2 1.92;
C3 0;
sigmak 1;
sigmaEps 1.3;
}

No MRF models present

No finite volume options present
Courant Number mean: 1.03659e-07 max: 4.64481e-05

Starting time loop

Courant Number mean: 1.03659e-07 max: 4.64481e-05
deltaT = 0.000119048
Time = 0.000119048

Killed

[Tobermory]

Did you forget to include your question?