How to define inlet and outlet on complex geometry

[Daniel Grafton]

Hi everyone, very new to Ansys Discovery (student version) and I'm trying to conduct a CFD on a model of the upper airways. 

The below red outline is of the outlet, with lots of facets. Inlets are similar (nostrils).

How would i go about definining the inlet/outlets for a CFD analysis ? Appreciate any and all help on this ! 

[peteroznewman]

Watch this video and pay attention at the 3:40 mark for a method to replace those facets with a single face.

[Daniel Grafton]

Thanks a lot Peter! very helpful 

Do i have to convert my shape to geometry first using auto skin  ? 

Otherwise when I split shape like in the video i just get a hole into the hollow shape, or if i cap the hole, it caps with a lot of facets again (see pics below).