I want to know how to use the multiple refernce frame (fluent 5) to model the flow around the stirrer. I used one circular section of grid around the stirrer, this region is solved in reference frame, while the outer region is solved in stationnary reference frame. but i' m not sure is good idea to do that, because the stirrer 's ends are too near the tank's wall.

Thanks for your help

Dear fawzy

Yes. You are right if you have baffle near the tank wall. You said 'the stirrer 's ends are too near the tank's wall'. Then, how do you have baffle(or plate) near the tank wall ? If you do not have any baffle near the wall, then you don't need to separate fluid region by two region. Single reference frame is correct way, theoretically and physically.

One comment : steady flow with multiple reference frame is approximation of unsteady flow. Whereas, single reference frame is physically steady flow.

Sincerely, Jinwook

Dear Jinwook

Thanks for your advice

sincerely, fawzy