Custom convergence criteria

costabarro95 · September 30, 2021, 05:42

Hello everybody, do you think that there is a way to stop the simulation using a criteria that is not based on residuals?
I was wondering if there is a way to stop it when a certain force value is reached

Yann · September 30, 2021, 05:57

Hi,

If you are using the ESI-OpenCFD branch (openfoam.com), you can use the runTimeControl function object : https://www.openfoam.com/documentati...e-control.html

This function has been introduced in OpenFOAM-v3.0+ so you should have it in pretty much any version of the ESI-OpenCFD branch.

I'm not aware of a similar functionality in the OpenFOAM foundation branch (openfoam.org) but I would be happy to learn about it if it exists.

Cheers,
Yann

costabarro95 · September 30, 2021, 07:28

ok, thank you for the answer. Actualy the situation is a bit more complicated, cause I want to create a convergence criteria on the force, that is confronting the last n values of the force and if the difference is lower than a certain value the simulation is stopped.

Yann · September 30, 2021, 07:51

Isn't it pretty close to one of the examples provided in the documentation?

Quote:

if the average drag coefficient remains within a 0.001 range over a window of 20 steps and the maximum momentum equation residual falls below 1e-4

costabarro95 · September 30, 2021, 07:59

You're right!.But on openFoam 9 I wasn't able to find that function

Yann · September 30, 2021, 08:38

Yes, as I was saying earlier, this function is not available in the OpenFOAM foundation branch (openfoam.org), but only in the ESI-OpenCFD branch (openfoam.com)

Sorry but I don't have a solution for the foundation versions.

Yann

Anup Singh · October 1, 2021, 11:15

Either go for the solution control library associated with your solver and after customizing attach it with your solver.
Or just get the solution control directly into your solver and modify the loops according to your needs.

September 30, 2021, 05:42	Custom convergence criteria	#1
costabarro95 New Member costantino barro Join Date: Sep 2021 Posts: 16 Rep Power: 5	Hello everybody, do you think that there is a way to stop the simulation using a criteria that is not based on residuals? I was wondering if there is a way to stop it when a certain force value is reached

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September 30, 2021, 05:57		#2
Yann Senior Member Yann Join Date: Apr 2012 Location: France Posts: 1,170 Rep Power: 27	Hi, If you are using the ESI-OpenCFD branch (openfoam.com), you can use the runTimeControl function object : https://www.openfoam.com/documentati...e-control.html This function has been introduced in OpenFOAM-v3.0+ so you should have it in pretty much any version of the ESI-OpenCFD branch. I'm not aware of a similar functionality in the OpenFOAM foundation branch (openfoam.org) but I would be happy to learn about it if it exists. Cheers, Yann

September 30, 2021, 07:28		#3
costabarro95 New Member costantino barro Join Date: Sep 2021 Posts: 16 Rep Power: 5	ok, thank you for the answer. Actualy the situation is a bit more complicated, cause I want to create a convergence criteria on the force, that is confronting the last n values of the force and if the difference is lower than a certain value the simulation is stopped.

September 30, 2021, 07:59		#5
costabarro95 New Member costantino barro Join Date: Sep 2021 Posts: 16 Rep Power: 5	You're right!.But on openFoam 9 I wasn't able to find that function

September 30, 2021, 08:38		#6
Yann Senior Member Yann Join Date: Apr 2012 Location: France Posts: 1,170 Rep Power: 27	Yes, as I was saying earlier, this function is not available in the OpenFOAM foundation branch (openfoam.org), but only in the ESI-OpenCFD branch (openfoam.com) Sorry but I don't have a solution for the foundation versions. Yann

October 1, 2021, 11:15		#7
Anup Singh New Member Anup Singh Join Date: Mar 2020 Posts: 22 Rep Power: 6	Either go for the solution control library associated with your solver and after customizing attach it with your solver. Or just get the solution control directly into your solver and modify the loops according to your needs.