[abminternet]

Hi foamers,

Has anyone encountered this error before and succesfully solved it??

From function specieThermo<thermo>::T(scalar f, scalar T0, scalar (specieThermo<thermo>::*F)(const scalar) const, scalar (specieThermo<thermo>::*dFdT)(const scalar) const) const
in file /opt/software/openfoam/extend/OpenFOAM-1.6-ext/src/thermophysicalModels/specie/lnInclude/specieThermoI.H at line 73
Maximum number of iterations exceeded. Rescue by HJ

I am getting it in two different cases, one steady state and one transient. I have read some threads and they say lowering some relaxation factors could solve it, so I tried it for the steady state case, and it just goes on for a couple more iterations but then it fails again. For the transient case I get it once and the solver stops. Any suggestions??? Thanks in advance.

[masuarez]

I have the same problem... i'm using chtMultiRegionFoam. If you find out anything, please let me know. I'll keep looking and see what I can find out.

Miguel

[PeterBishop]

I'm experiencing the same problem, any news?

[Farshad_Noravesh]

Hi,

I have the same problem in rhoCentralFoam.

Farshad

[kalle]

This thread may provide solution(s):

http://www.cfd-online.com/Forums/ope...ombustion.html

If specieThermo cannot invert h(T) to give T iteratively, usually two things can be wron: Either is the h(T) function erroneous, like in the thread above, or your enthalpy equation is diverging in your solver, giving extreme values of h. In the former case, review the thermo input data. In the latter case, you should investigate why you get such values for h.

K

[hz283]

Hi,

I also had this problem last week. The density is negative, which may be caused by wrong calculation of pressure or enthalpy (energy). But I think the true reason is diverse and case by case. For my simulation, I modified the mesh (remove some cell of bad quality), and the simulation seems good now. Maybe this issue can be caused by not suitable BC specification, and so on.

[calf.Z]

Originally Posted by kalle

This thread may provide solution(s):

http://www.cfd-online.com/Forums/ope...ombustion.html

If specieThermo cannot invert h(T) to give T iteratively, usually two things can be wron: Either is the h(T) function erroneous, like in the thread above, or your enthalpy equation is diverging in your solver, giving extreme values of h. In the former case, review the thermo input data. In the latter case, you should investigate why you get such values for h.

K

Thank you for giving me some hints.

According to my simulation, the error appeared during the first iteration:

PIMPLE: iteration 1
DILUPBiCGStab: Solving for Ux, Initial residual = 1, Final residual = 0.0720087, No Iterations 1
DILUPBiCGStab: Solving for Uy, Initial residual = 1, Final residual = 0.063316, No Iterations 1
DILUPBiCGStab: Solving for Uz, Initial residual = 1, Final residual = 0.0684356, No Iterations 1
DILUPBiCGStab: Solving for h, Initial residual = 1, Final residual = 0.0749308, No Iterations 2

--> FOAM FATAL ERROR:
Maximum number of iterations exceeded: 1000
......
FOAM aborting

#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::error::abort() at ??:?
#2 Foam::heRhoTabularThermo<Foam::rhoThermo, Foam:ureMixture<Foam::tabularTransport<Foam::spe cies::thermo<Foam::hTabularThermo<Foam::tabularEOS <Foam::specie> >, Foam::sensibleEnthalpy> > > >::calculate() at ??:?
#3 Foam::heRhoTabularThermo<Foam::rhoThermo, Foam:ureMixture<Foam::tabularTransport<Foam::spe cies::thermo<Foam::hTabularThermo<Foam::tabularEOS <Foam::specie> >, Foam::sensibleEnthalpy> > > >::correct() at ??:?


I think this error is related to h and T, but I have no idea where I should check. Maybe there are some mistakes with my code or setting.

Any suggestion is highly appreciated.