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-   -   CFX-Pre: Physics of Flow in Bearing (http://www.cfd-online.com/Forums/cfx/20703-cfx-pre-physics-flow-bearing.html)

R P October 11, 2004 00:58

CFX-Pre: Physics of Flow in Bearing
 
Needed ur guidance in modeling flow thru a bearing. I have a sector model, for my requirements its 24 degree sector. Now as you might be aware, for the fluid volume in the bearing space between the rotating shaft and the bearing surface, we have motion accorded to different surfaces. If my understanding is correct, the fluid domain should be stationary, its inner surface should be rotating at the speed of the shaft and the outer surface should be stationary. Would you be kind enough to correct me? One of my friends is trying in a different approach, which I presume is wrong, Fluid Volume "Rotating" FFluid Volume Inner surface "rotating" and Fluid Outer Surface is "Counterrotating". Which of the aofresaid physics definition is correct for the described condition? I would be very much helpful if you can kindly help me with the physcics defintion.

RP

Glenn Horrocks October 14, 2004 18:44

Re: CFX-Pre: Physics of Flow in Bearing
 
Hi,

I assume you are modelling a journal bearing or similar application. The good news is that if correctly applied, either method (that is either a stationary or a rotating domain) should give the same answer. It is likely that the stationary frame of reference simulation will be easier to set up and converge.

Frames of reference should be viewed in terms of what is required to describe the motion of the mesh you want, rather than what the fluid does. A rotating frame of reference should be used when the mesh required to describe the motion rotates.

Glenn Horrocks

R P October 15, 2004 01:03

Re: CFX-Pre: Physics of Flow in Bearing
 
Glen,

Thanks for your help. Now I have got how it works in CFX.

R P


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