converting wall to interface
 

Hi everyone,

I'm trying to run an mrf simulation. It's basically a wind turbine in a square wind tunnel. Around the wind turbine, I have a cylindrical volume for the rotational reference frame. In gambit, I had defined the interface as wall prior to export. The problem now is that I am unable to convert the wall into an interface boundary condition in fluent! Somehow the wall only has the other options of fan, interior, porous and wall. I looked at the other walls, and those had all the fluent boundary condition options.

What gives? I'm stumped.