[FrankS]

Hi All,
I am trying to simulate a miniature 2-lobe roots blower I designed. I tried to use the Immersed Solid option in CFX but I had little luck. I think the word "Solid" should be replace by "porus media". I tried all the tricks including a super-fine mesh and the momentum forcing function at 100 but no dice; flow-through solids.

After some reading, I was thinking that I could use the Fluent DEFINE_GEOM UDF to deform the mesh interface between each lobe. I know the shape of each lobe and I could define the shape of the interface with lobe angle.

I would set each lobe in a cylinder shaped domain and deform the interface with the UDF, in effect creating a sliding mesh. I picture in my head the shape of the interface would look like the Yin and Yang symbol (http://en.wikipedia.org/wiki/Yin_and_yang). So, to anybody with experience doing something similar, does this plan seem logical?

I don't have much experience with Fluent but I am willing to put in the hours to learn. My most advanced programming experience consists of writing a 2-D, laminar Navier-Stokes solver in C++ but I can always read a book if I need programming help. Any input would be appreciated. An animation ripped off of Youtube is in the link:
http://www.youtube.com/watch?v=_-fwWrFLiyY

Thanks
Frank