Solution is converging but have reverse flow on pressure outlet

Dinesh_Dhande · June 20, 2013, 04:14

Dear Friends,
Hi!
I am modelling a hydrodynamic journal bearing which is nothing but one cylinder rotating inside a stationary cylinder and there is a fluid flow thru annulus (which is @50 microns). I have modeled rotating member as a shaft(@3000 RPM) and stationary as bearing. The 50 microns lubricant film is meshed into 32 layers.
My solution is converging but i am facing reverse flow problem at pressure outlet. Is this reverse flow expected in such cases? or if not how to get rid of it?
Thanks in advance

zhihuawan · March 10, 2018, 22:29

have you solve it ,I meet the same question?

Hamidzoka · March 11, 2018, 02:02

In a CFD run generally reverse flow happens if the boundaries are so close to the object(hear bearing) such that gradients of flow parameters like pressure are high. Therefore flow reversal happens to meet the preset outlet boundary condition. It seems you need to adjust the outlet boundary. If the amount of reverse flow is quite low and the results are satisfactory there is no need to modify the domain.

June 20, 2013, 04:14	Solution is converging but have reverse flow on pressure outlet	#1
Dinesh_Dhande New Member Dinesh Join Date: Nov 2009 Location: India Posts: 25 Rep Power: 17	Dear Friends, Hi! I am modelling a hydrodynamic journal bearing which is nothing but one cylinder rotating inside a stationary cylinder and there is a fluid flow thru annulus (which is @50 microns). I have modeled rotating member as a shaft(@3000 RPM) and stationary as bearing. The 50 microns lubricant film is meshed into 32 layers. My solution is converging but i am facing reverse flow problem at pressure outlet. Is this reverse flow expected in such cases? or if not how to get rid of it? Thanks in advance

March 10, 2018, 22:29	have you solve it ,I meet the same question?	#2
zhihuawan Member wan zhihua Join Date: Dec 2017 Posts: 67 Rep Power: 9	have you solve it ,I meet the same question?

March 11, 2018, 02:02		#3
Hamidzoka Senior Member Hamid Zoka Join Date: Nov 2009 Posts: 293 Rep Power: 19	In a CFD run generally reverse flow happens if the boundaries are so close to the object(hear bearing) such that gradients of flow parameters like pressure are high. Therefore flow reversal happens to meet the preset outlet boundary condition. It seems you need to adjust the outlet boundary. If the amount of reverse flow is quite low and the results are satisfactory there is no need to modify the domain. harishkamat100 likes this.

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