Flow Between Concentric Cylinders
 

Hello!
Please, could you help me?

I have the follow task:

Consider the steady flow maintained between two infinite concentric cylinders. Inner cylinder makes harmonic motions. Outer cylinder remains fixed.
Determine the velocity distribution between the two cylinders.
It's two-dimensional problem.

http://www.freeimagehosting.net/uploads/14bdbf7c94.jpg

I've seen the similar task in VM46. But It isn't the same. Unfortunately, I don't know how to set harmonic motions...

If you help me, it'll be wonderful :)