Help with fluid flow analysis on imported SolidWorks file.

Hi all

I have imported a SolidWorks assembly into COMSOL 3.5a using the IGS file format.
It is a smaller section of a larger nozzle that should produce swirling flows.
I have attached a screenshot of what it looks like, both solid and wire-frame.
What I am trying to do is a fluid flow analysis of a fluid flowing through it.
(In the model navigator I selected 3D, COMSOL Multiphysics, Fluid Flow, Incompressible...).
I am now trying to set boundary conditions so that the openings of the smaller ports are inlets
and the opening of the larger section at the top is an outlet, but the edge settings option in
the Physics drop down menu is grayed out and when in the boundary settings window, I can
only select the internal walls to set the boundary conditions.

Am I going about this in the wrong way, or is there something that I don't know and am missing?

Any help would be IMMENSELY appreciated.

Thanks

Brett