oscillating obstacle in 2 D flow
 

I am trying to model an oscillating obstacle placed in a flow. I am using the software Fluent for this purpose. The analysis is being done on a 2-D rectangular channel. An obstacle is placed at the base of the rectangular channel which oscillates at a certain frequency. Please advice on how to formulate the problem, i.e. the UDF for the obstacle, dynamic mesh etc.

Thanking you

Sumeet