How to rotate a wall?( with udf)
 

Dear Friends,
I want to solve a problem with Fluent. This problem is like a Piston-Cylinder device but the piston doesn't have a linear movement and it's going to rotate about a specific point.
Another point about this problem is that the piston is going to move by fluid pressure. Thus I need a UDF to rotate my wall by computing shear stress around its wall.
Is there anyone who write this udf? or solve a similar problem?
I would be glad if anyone could help me
Thanks
Yours sincerely,
Pejman