OF11 MRF problems

ufocfd · February 2, 2024, 05:10

I am running an MRF propeller demo case at quite low rpm (600rpm) in simpleFoam.
It works fine in OF10 but doesn't work in OF11. Its a continuous mesh, so not using NCC or AMI.
I'm just specifying the rotation on an MRF zone (defined using cylinder within SHM).

https://drive.google.com/file/d/1h4l...ew?usp=sharing

https://drive.google.com/file/d/1KnB...ew?usp=sharing

ufocfd · February 5, 2024, 06:06

Well thanks to a testcase (from Pedro) I realised what the problem was.
You need to have this BC in the "U" file. I never heard of this one before,
but in OF11 this is the BC needed to get MRF to work. Thanks Pedro!

type MRFnoSlip;
value uniform (0 0 0);

Here is a nice image the surface velocity:
https://drive.google.com/file/d/1AGY...ew?usp=sharing

February 2, 2024, 05:10	OF11 MRF problems	#1
ufocfd Senior Member Giles Richardson Join Date: Jun 2012 Location: Cambs UK Posts: 100 Rep Power: 13	I am running an MRF propeller demo case at quite low rpm (600rpm) in simpleFoam. It works fine in OF10 but doesn't work in OF11. Its a continuous mesh, so not using NCC or AMI. I'm just specifying the rotation on an MRF zone (defined using cylinder within SHM). https://drive.google.com/file/d/1h4l...ew?usp=sharing https://drive.google.com/file/d/1KnB...ew?usp=sharing

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February 5, 2024, 06:06		#2
ufocfd Senior Member Giles Richardson Join Date: Jun 2012 Location: Cambs UK Posts: 100 Rep Power: 13	Well thanks to a testcase (from Pedro) I realised what the problem was. You need to have this BC in the "U" file. I never heard of this one before, but in OF11 this is the BC needed to get MRF to work. Thanks Pedro! type MRFnoSlip; value uniform (0 0 0); Here is a nice image the surface velocity: https://drive.google.com/file/d/1AGY...ew?usp=sharing