oscillatory flow

Hi Dear All,
Can some body know if we have oscillatory flow on the side wall boundaries (top and bottom) so which kind of boundary conditions will be more good to used in such situations. Thanks in advance and waiting for some kind response.

I do not exactly get what you mean. Can you explain it in more detail?

Hi Dear Timm,
I mean when you have zero velocity components on the top and bottom walls so usually we used the bounceback boundary conditions like(u=0 and v=0). Now if we have oscillatory flow on the top and bottom walls like(u=Ui(1+asin2piFf*t and v=0) where a=amplitude and Ff is the forcing frequency. So in such situations which type of boundary condition we can used for top and bottom walls.
Thanks and best regards

Dear Khan,
you can also use bounce-back boundary conditions, but you have to modify them. Tony Ladd has investigated this. You should have a look at his papers.
You can use velocity boundary conditions as well. It would be best to read the paper by Jonas et al.