Convergence issue due to high rotational speed

Shuttle · November 3, 2022, 09:41

Hello,

I am currently simulating a gap between the rotor (rotating at 12000 RPM) and stator with eccentricity in Fluent, however, I am getting a reverse flow both at the inlet and outlet, at inlet some reverse flow is expected, but at the outlet not. I am trying to verify my model based on a research paper. Because of that, I am also having convergence issues with continuity. I found some solutions on the internet but they are somehow not working. I didn't try to extend my domain because of the dimensions given in the paper. Any suggestion would be nice, as I am stuck due to that in my work.

MicrosoftTeams-image.png MicrosoftTeams-image (1).jpg

fredo490 · November 4, 2022, 15:48

Extend your domain, that is the only solution.
Just be careful to extend the domain in a way that preserve the test conditions (pressure, turbulence intensity,...) in your test sections.

You will be surprise by how many papers hide this kind of 'tricks' because it does not look good on a publication.

November 3, 2022, 09:41	Convergence issue due to high rotational speed	#1
Shuttle New Member Shuttle Join Date: Jul 2022 Posts: 5 Rep Power: 3	Hello, I am currently simulating a gap between the rotor (rotating at 12000 RPM) and stator with eccentricity in Fluent, however, I am getting a reverse flow both at the inlet and outlet, at inlet some reverse flow is expected, but at the outlet not. I am trying to verify my model based on a research paper. Because of that, I am also having convergence issues with continuity. I found some solutions on the internet but they are somehow not working. I didn't try to extend my domain because of the dimensions given in the paper. Any suggestion would be nice, as I am stuck due to that in my work. MicrosoftTeams-image.png MicrosoftTeams-image (1).jpg

November 4, 2022, 15:48		#2
fredo490 Senior Member HECKMANN Frédéric Join Date: Jul 2010 Posts: 249 Rep Power: 16	Extend your domain, that is the only solution. Just be careful to extend the domain in a way that preserve the test conditions (pressure, turbulence intensity,...) in your test sections. You will be surprise by how many papers hide this kind of 'tricks' because it does not look good on a publication. Shuttle likes this.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[openSmoke] LaminarSMOKE compilation error	mdhfiz	OpenFOAM Community Contributions	7	October 4, 2022 13:57
interFoam Simulation speed and convergence graph	caganini	OpenFOAM Running, Solving & CFD	0	April 12, 2022 03:34
Air filter holder, questions about high turbulence viscosity and convergence	clmr90	FLUENT	0	January 24, 2019 15:38
High speed compressible flow through pipe	Munni	Main CFD Forum	6	December 7, 2015 11:33
Convergence Speed	Maciej Matyka	Main CFD Forum	1	June 12, 2003 12:20