I want to model a turbine wheel (similar to a pelton type) which rotates and scoops up fluid which lies at the bottom. Above the water is air. It is a 2-D model but I am not sure how to approach the problem. Any suggestions on which models to use or how to account for the two phases. If there is anything like a simple solution then that is what I am looking for?

Thanks

VOF + sliding mesh in FLUENT 5.4 or greater.

What is your ultimate goal?

I want to determine the torque on the turbine wheel for different geometries (i.e. change the shape of the buckets and look at the required torque)