CFD Online Discussion Forums - rhoSimpleFoam :: Maximum number of iterations exceeded

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rhoSimpleFoam :: Maximum number of iterations exceeded

Hi all,

I am trying to solve a case with time varying Boundary conditions using uniformValue and rhoSimpleFoam.

The input given for patches in p and T is in tabular form while the U is set as 'pressureInletVelocity'

It is solving upto 2 clock time while afterwards it says

Quote:

Time = 0.0003

DILUPBiCG: Solving for Ux, Initial residual = 0.416261, Final residual = 2.23461e-07, No Iterations 10
DILUPBiCG: Solving for Uy, Initial residual = 0.46579, Final residual = 9.685e-07, No Iterations 10
DILUPBiCG: Solving for Uz, Initial residual = 0.417807, Final residual = 2.21784e-07, No Iterations 12
DILUPBiCG: Solving for h, Initial residual = 0.558075, Final residual = 1.35032e-08, No Iterations 3

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

From function thermo<Thermo, Type>::T(scalar f, scalar T0, scalar (thermo<Thermo, Type>::*F)(const scalar) const, scalar (thermo<Thermo, Type>::*dFdT)(const scalar) const, scalar (thermo<Thermo, Type>::*limit)(const scalar) const) const
in file /home/opencfd/OpenFOAM/OpenFOAM-2.2.2/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 76.

FOAM aborting

#0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::error::abort() in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 Foam::species::thermo<Foam::hConstThermo<Foam::per fectGas<Foam::specie> >, Foam::sensibleEnthalpy>::T(double, double, double, double (Foam::species::thermo<Foam::hConstThermo<Foam::pe rfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::pe rfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::pe rfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::*)(double) const) const in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#3 Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam::perfectGas<Foa m::specie> >, Foam::sensibleEnthalpy> > > >::calculate() in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#4 Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::speci es::thermo<Foam::hConstThermo<Foam::perfectGas<Foa m::specie> >, Foam::sensibleEnthalpy> > > >::correct() in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#5
in "/opt/openfoam222/platforms/linux64GccDPOpt/bin/rhoPorousSimpleFoam"
#6 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7
in "/opt/openfoam222/platforms/linux64GccDPOpt/bin/rhoPorousSimpleFoam"
Aborted (core dumped)

I tried to resolve the issue using http://www.cfd-online.com/Forums/ope...implefoam.html

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

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

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

but got the same results.

Now I changed the solver for 'p' from GAMG to DICPCG and next time to PCG (because I think that the problem is with 'p' only).

and still the same thing.

Please help me ASAP...

Thanks and Regards,
Adarsh Tiwari

Dear Adarsh,

rhoSimpleFoam is a steady-state solver. If you want use time varying boundary condition try to use rhoPimpleFoam

Greetings Betakv,

I have already simulated using rhoPimpleFoam but I got some fancy results, with best of my knowledge I can say that the probability of getting appropriate results is much more higher in rhoSimpleFoam.

It would be great help if you provide me some tutorials about rhoSimpleFoam, I already have one, but it is not worth about this case. :):)

Thanks and Regards,
Adarsh Tiwari

Dear Adarsh,

there are number of reasons( boundary/initial condition, solver setting, ... ) why you got fancy results. Can you send description of your case?

Greeting Betakv,

sorry for late reply.

The file is too large to upload hence i am attaching the brief version of the same but by removing some of the data-table entries.

In pressure files I have also tried with the uniformTotalPressure but still got nothing

in solution schemes also i have changed form GAMG to different solver. I have also tried with faceCente and cellCenter schemes.

Thanks and Regards,
Adarsh Tiwari

Dear Adarsh,

you have quite lot of errors in boundary condition especially on the inlet and outlet.
On the inlet you have to prescribe a totalPressure bc for pressure. On the outlet you have to prescribe zeroGradient or inletOutlet bc for velocity and temperature

betakv

Quote:

Originally Posted by adarsh tiwari (Post 486397)

hi Betakv,

As I already informed you that the p and T boundary conditions are fixed, only thing I can play with is U.

I used zeroGradient and inletOutlet bc for velocity with different combinations but still getting the same message out.