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-   -   rhoSimpleFoam :: Maximum number of iterations exceeded (https://www.cfd-online.com/Forums/openfoam-solving/132946-rhosimplefoam-maximum-number-iterations-exceeded.html)

 adarsh tiwari April 8, 2014 08:18

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::T(scalar f, scalar T0, scalar (thermo::*F)(const scalar) const, scalar (thermo::*dFdT)(const scalar) const, scalar (thermo::*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::sensibleEnthalpy>::T(double, double, double, double (Foam::species::thermo >, Foam::sensibleEnthalpy>::*)(double, double) const, double (Foam::species::thermo >, Foam::sensibleEnthalpy>::*)(double, double) const, double (Foam::species::thermo >, Foam::sensibleEnthalpy>::*)(double) const) const in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so" #3 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::calculate() in "/opt/openfoam222/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so" #4 Foam::heRhoThermo >, 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

 betakv April 12, 2014 01:56

Dear Adarsh,

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

 adarsh tiwari April 14, 2014 01:32

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

 betakv April 14, 2014 02:00

Dear Adarsh,

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

 adarsh tiwari April 16, 2014 03:20

1 Attachment(s)
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

 betakv April 16, 2014 04:47

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) 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

 adarsh tiwari April 22, 2014 07:49

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.

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