CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Exceeded iterations for high molar masses.

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 30, 2013, 08:12
Default Exceeded iterations for high molar masses.
  #1
New Member
 
Join Date: Apr 2012
Posts: 9
Rep Power: 13
CoolKau is on a distinguished road
I have been running a simulation for quite a while. I tried different pressures, slightly different geometries, boundary conditions. I used Hydrogen and never ran into problems. Now, I wanted to repeat the simulations in Argon. So I changed the thermo properties and the simulation crashes always, no matter what I try. I identified the error to be connected to the molar mass. With all parameters the same but the molar mass the error occurs when the molar mass exceeds 8.

The error is posted below. It always occurs at the second time step.

I tried various time steps and initial conditions. I tried to run the simulation with hydrogen first and then switched the molar mass. I played with the grid size.

I used OpenFoam 2.2.1, sonicFoam with
thermoType
{
type hePsiThermo;
mixture pureMixture;
transport const;
thermo eConst;
equationOfState perfectGas;
specie specie;
energy sensibleInternalEnergy;
}


If needed I am happy to give more information about the setup.

I am sorry if my question might be silly as I am not an expert in OpenFoam.
But thank you very much for your help in advance.




Time = 1e-11

Courant Number mean: 0 max: 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 2.68031e-06, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 1.4784e-07, No Iterations 1
DILUPBiCG: Solving for e, Initial residual = 1, Final residual = 4.40894e-08, No Iterations 2
DILUPBiCG: Solving for p, Initial residual = 1, Final residual = 9.96913e-14, No Iterations 1
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 3.36116e-15, global = -3.32923e-15, cumulative = -3.32923e-15
DILUPBiCG: Solving for p, Initial residual = 6.26642e-17, Final residual = 6.26642e-17, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 5.78765e-14, global = -3.32853e-15, cumulative = -6.65776e-15
DILUPBiCG: Solving for omega, Initial residual = 0.000975322, Final residual = 1.44466e-12, No Iterations 2
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 3.6463e-09, No Iterations 2
ExecutionTime = 0.23 s ClockTime = 0 s

Time = 2e-11

Courant Number mean: 3.25537e-14 max: 1.0717e-10
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 0.334038, Final residual = 1.4194e-08, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.318687, Final residual = 6.53075e-09, No Iterations 1
DILUPBiCG: Solving for e, Initial residual = 7.92849e-05, Final residual = 1.35329e-09, No Iterations 1


--> 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 /apps/OpenFOAM//OpenFOAM-2.2.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 76.
CoolKau is offline   Reply With Quote

Old   October 31, 2013, 15:07
Default
  #2
New Member
 
Join Date: Apr 2012
Posts: 9
Rep Power: 13
CoolKau is on a distinguished road
After going through all the different input parameters i realized that I set the initial internal temperature too low. This is already indicated by the Thermo function failing.

High molar masses seem to be more sensitive to temperature.
CoolKau is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 07:20
pimpleFoam: turbulence->correct(); is not executed when using residualControl hfs OpenFOAM Running, Solving & CFD 3 October 29, 2013 09:35
calculation stops after few time steps sivakumar OpenFOAM Running, Solving & CFD 7 March 17, 2013 07:37
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 bookie56 OpenFOAM Installation 8 August 13, 2011 05:03
Orifice Plate with a fully developed flow - Problems with convergence jonmec OpenFOAM Running, Solving & CFD 3 July 28, 2011 06:24


All times are GMT -4. The time now is 20:20.