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-   -   Rotating Fluids (http://www.cfd-online.com/Forums/fluent/45416-rotating-fluids.html)

Xiana July 17, 2007 11:20

Rotating Fluids
 
Hi, does anyone simulate rotating fluids? Im trying to simulate the flow inside a tubular centrifuge but I have a lot of convergence problems up a certain Reynolds number (1000). I use Reynolds stress model to simulate the turbulences. I would appreciate any help!

Xiana

Joe July 17, 2007 12:23

Re: Rotating Fluids
 
Initialise your RSM model with an isotropic turbulence model's results.

Ressel July 17, 2007 13:47

Re: Rotating Fluids
 
I would try... check the mesh refined and time step.


red lemon July 18, 2007 16:20

Re: Rotating Fluids
 
Also try FMG initialisation and run with PRESTO if using pressure based solver

garima chaudhary July 19, 2007 04:14

Re: Rotating Fluids
 
first of all u need to know by the data (i mean any experimental data availabe or any information available ) whether u r in turbulkent regime or not if not then y r u using turbulence model. i m also working in cfd field on centrifugal rotators only, but does ur system contains 2 fluids or only single fluid wat is the system can u tell me in detail , bcoz my system consists of 2 fluids, hence me using vof model , anyway tell me wat is the system

Xiana July 19, 2007 07:00

Re: Rotating Fluids
 
Thank you for your advices. The problem is that I have no yet experimental data (Im working on it but its going to go for a long time.Ive tried with turbulence models because it didnt converged with laminar, but i think the problem is there. I simulate only one fluid and then, when streams are converged, I make some particle injections (concentration is very low and DPM works good). I simulated the interface fluid-air once with the VOF model and now I define this interface as a wall with no shear stress. The external wall and the blades of the centrifuge are moving walls and the fluid rotate in a moving reference frame. Do you think is a good formulation?

Xiana


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