Frame motion and boundary condition
 

Hello every one,
I am doing simulation chemical vapor deposition (CVD) of rotating reactor, pic 1. explain it in simple words it is a flow impinging a rotating disk. I put rotation value in boundary condition for the disk,pic 2. I repeat the solution using frame motion, pic 3. I am confused between these two results, which one is the correct, and why in frame motion entire flow is rotating. Any recommendations and hints are valuable to me. thank you in advance.

Both results are roughly correct :-) In the rotating frame case the velocity you are plotting is relative to the frame motion, so it's mainly counter-rotating. Plot Velocity in Stationary Frame to see the "intuitive" result. The stationary frame case should be more accurate - as a general rule pick the frame motion that is closest to the expected velocity field to minimize numerical errors. Note that if your disc was not a surface-of-revolution then rotating frame is the only valid approach.

Note that if your disc was not a surface-of-revolution then rotating frame is the only valid approach.[/QUOTE]

Dear stumpy,
Thank you for replying. in my case the entire reactor is stationary and only the disk is rotating. thanks