[bussaco8]

Hello everyone!


I have an OpenFOAM case that uses chtMultiRegionSimpleFoam, with k-omegaSST turbulence model for the fluid.
If I start the simulation, it achieves the maximum iterations error. However, I know that if I start the simulation in laminar and then change it to turbulence model k-omegaSST, the case will run just fine.


How do I change from laminar to turbulent k-omegaSST during the execution? Or, at least, stop the laminar case and change it to turbulent without reseting anything, by "using" the values achieved so far by the laminar case?


Thanks!
João Gil

[Santiago]

Originally Posted by bussaco8

Hello everyone!


I have an OpenFOAM case that uses chtMultiRegionSimpleFoam, with k-omegaSST turbulence model for the fluid.
If I start the simulation, it achieves the maximum iterations error. However, I know that if I start the simulation in laminar and then change it to turbulence model k-omegaSST, the case will run just fine.


How do I change from laminar to turbulent k-omegaSST during the execution? Or, at least, stop the laminar case and change it to turbulent without reseting anything, by "using" the values achieved so far by the laminar case?


Thanks!
João Gil

So why dont you do one simulation in "laminar" mode and then lauch another one with the turbulence model and results obtained previously.

[bussaco8]

I don't know how to use the results obtained from laminar mode into the turbulence simulation. How do I manipulate the folders and such...? And also, when I execute the solver in the terminal, how do I make sure that it's using the initial results from laminar?

[mbuergle]

Originally Posted by bussaco8

I don't know how to use the results obtained from laminar mode into the turbulence simulation. How do I manipulate the folders and such...? And also, when I execute the solver in the terminal, how do I make sure that it's using the initial results from laminar?

I would proceed as follows:

1. Create a new case directory with the desired turbulence model in the "constant/turbulenceProperties" file
2. Delete the 0 directory
3. Copy the results (latest time directory containing the fles U, p_rgh, etc.) from the laminar simulation into the new turbulent case directory and rename the directory to 0
4. Add files for turbulent variables (k/epsilon/nut or whatever you chose) into 0 directory
5. Start turbulent simulation with laminar results as initial condition

[bussaco8]

Thanks for the suggestion @mbuergle; unfortounately, it didn't work.
I believe the correct way is:
1 - Run the laminar simulation until a certain time;
2 - On the last time of the laminar simulation, add the files for turbulent variables (k, omega, etc...);
3 - Change the turbulentceProperties files to the desired turbulence model.


But even like that, I get the 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::hPolynomialThermo<Foam::icoPolynomial<Foam::specie> >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie> >, Foam::sensibleEnthalpy>]
    in file /home/ubuntu/OpenFOAM/OpenFOAM-4.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66.

I think there are a lot of threads in the forum about this error. I'll research more
I use the polynomial method for my fluid region.


Thanks a lot for your help!
Cheers,
João Gil