[rouxel92]

Hi,

does someone know how to solve this type of error?

--> FOAM FATAL ERROR:
Maximum number of iterations exceeded

From function Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo<Foam:erfectGas<Foam::specie> >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam:er fectGas<Foam::specie> >, Foam::sensibleEnthalpy>]
in file /opt/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66.

FOAM aborting

#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::error::abort() at ??:?
#2 Foam::heRhoThermo<Foam::rhoThermo, Foam:ureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam:erfectGas<Foa m::specie> >, Foam::sensibleEnthalpy> > > >::calculate() at ??:?
#3 Foam::heRhoThermo<Foam::rhoThermo, Foam:ureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam:erfectGas<Foa m::specie> >, Foam::sensibleEnthalpy> > > >::correct() at ??:?
#4 ? at ??:?
#5 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#6 ? at ??:?
Aborted



Thanks a lot,
Rouxel.

[Astan]

i think you could solve that problem just increasing the number of maximum iteration in fvSolution, the default value is 1000 iterations.

Just change the maximum number of iterations in fvSolution, wrote for example at the bottom maxIter 5000:

For ex, in fvsolution you have:

k
{
solver
preconditioner
tolerance
etc etc
at the end you write:
maxIter 5000;
}

[rouxel92]

Hi Astan,
I've tried to solve the problem using the method you show me but nothing. Its gets me out the same error. And I've noticed another error during the heat transfert, the air's temperature is too high while the CO2's temperature is going down under the absolute zero.

Time = 136


Solving for fluid region air
DILUPBiCG: Solving for Ux, Initial residual = 0.002098765, Final residual = 6.930776e-06, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.002774326, Final residual = 1.104634e-05, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.00120054, Final residual = 1.327856e-05, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 0.002047173, Final residual = 0.0001522865, No Iterations 1
Min/max T:308.15 948.6779
GAMG: Solving for p_rgh, Initial residual = 0.003518778, Final residual = 0.0003325344, No Iterations 4
time step continuity errors : sum local = 0.0008735108, global = -0.0001081343, cumulative = -0.04066168
Min/max rho:0.3776146 1.145686
DILUPBiCG: Solving for omega, Initial residual = 5.100526e-05, Final residual = 2.376734e-06, No Iterations 1
DILUPBiCG: Solving for k, Initial residual = 0.001913631, Final residual = 8.322551e-05, No Iterations 1

Solving for fluid region co2
DILUPBiCG: Solving for Ux, Initial residual = 0.003080461, Final residual = 0.0002641697, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.003234555, Final residual = 0.000315537, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.0007038237, Final residual = 6.976397e-06, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 0.002124608, Final residual = 0.000104272, No Iterations 1


--> FOAM FATAL ERROR:
Maximum number of iterations exceeded

[Astan]

hi rouxel92, i suggest you to have a look at this post:

Maximum number of iterations exceeded

[rouxel92]

Hi Astan,
yeah i read it at all. And even during my research i found out that it migh be a mesh's problem. but i did the checkMesh before starting everthing and it was a pretty god mesh. i had the max non orthogonality aroud 17.

[Astan]

what's about the max skew and B.C?

Anyway, A thing that you could try is to use the smoothSolver solver insteat of PBiCG and GaussSeidel as smoother.

Or you could use PBiCGStab as solver (instead of PBiCG) with DILU as preconditioner (as you are already using).

if your case is about steady RANS, what's about the relaxation factor that you are using? Try to use low relaxation factors at first (for example 0.3) and once the computation goes on, you change for example 0.5 and so on).
A lower relaxation factor stabilizes the computation but the convergence speed is lower, you i suggest you to do a certain number of computation (just to stabilize) and then increase.

Try these settings.

[rouxel92]

the max skewness of the mesh i've used was 0.5261681. And reguarding the B.C. i don't know if i can upload it to you for you to get a quick look?