[overset] Overset mesh leaving background mesh domain

mcaus · September 2, 2021, 10:06

Hi everyone,

I'm interested in using OFs overset mesh functionality to simulate the closing of a valve. To do so, the overset mesh has to leave the domain of the background mesh, very much in the same way as done in this OF simulation:

https://www.youtube.com/watch?v=TGj80RCSaLU

with the code being available here:

https://github.com/Vignesh-S-P/Analy...using-OpenFOAM

I've read multiple times that the overset mesh has to be contained in the background mesh at all times and hence this kind of simulation should currently not be possible. And indeed the code only runs with v1806, but not later versions.
Does anyone know why this is the case? Is it safe to use v1806 for this type of simulation, or was it removed because of some particular flaw?

Thanks!

mAlletto · September 2, 2021, 14:58

I think if it runs on v1806 it should run with minor changes in the dictionaries also on newer versions. What kind of error you get?

mcaus · September 9, 2021, 08:39

In this specific case, using newer versions leads to the time step size going to zero (I have not looked into why exactly this happens).
I found a few more comments indicating that the overset mesh is generally not allowed to leave the background mesh (and hence the simulations shouldn't be running in v1806 as well). Can anyone confirm this?

mAlletto · September 9, 2021, 08:52

I did some simulations with foam extend a while ago and with this version it was possible one mesh to leave the domain

mcaus · September 9, 2021, 08:59

Thanks for the hint! I might give it a try with the foam-extend version then.

September 2, 2021, 10:06	[overset] Overset mesh leaving background mesh domain	#1
mcaus New Member Join Date: Aug 2021 Posts: 5 Rep Power: 5	Hi everyone, I'm interested in using OFs overset mesh functionality to simulate the closing of a valve. To do so, the overset mesh has to leave the domain of the background mesh, very much in the same way as done in this OF simulation: https://www.youtube.com/watch?v=TGj80RCSaLU with the code being available here: https://github.com/Vignesh-S-P/Analy...using-OpenFOAM I've read multiple times that the overset mesh has to be contained in the background mesh at all times and hence this kind of simulation should currently not be possible. And indeed the code only runs with v1806, but not later versions. Does anyone know why this is the case? Is it safe to use v1806 for this type of simulation, or was it removed because of some particular flaw? Thanks!

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September 2, 2021, 14:58		#2
mAlletto Senior Member Michael Alletto Join Date: Jun 2018 Location: Bremen Posts: 616 Rep Power: 16	I think if it runs on v1806 it should run with minor changes in the dictionaries also on newer versions. What kind of error you get?

September 9, 2021, 08:39		#3
mcaus New Member Join Date: Aug 2021 Posts: 5 Rep Power: 5	In this specific case, using newer versions leads to the time step size going to zero (I have not looked into why exactly this happens). I found a few more comments indicating that the overset mesh is generally not allowed to leave the background mesh (and hence the simulations shouldn't be running in v1806 as well). Can anyone confirm this?

September 9, 2021, 08:52		#4
mAlletto Senior Member Michael Alletto Join Date: Jun 2018 Location: Bremen Posts: 616 Rep Power: 16	I did some simulations with foam extend a while ago and with this version it was possible one mesh to leave the domain

September 9, 2021, 08:59		#5
mcaus New Member Join Date: Aug 2021 Posts: 5 Rep Power: 5	Thanks for the hint! I might give it a try with the foam-extend version then.