Volume displacement and airflow

I am studying the airflow through a computer case. In particular, the effect of multiple inflow/outflow fans and their placement. So, far I've modeled the case itself as the extents of the domain and used various faces as inlets or outlets, with a fixed global air flow, similar to the tutorials.

Is it possible to model more of a fan effect using directional volume displacement? Also, if I wanted to have openings that allowed flow in either direction would I have to change geometry to something similar to your air flow through a room.sym example?

Angular Velocity, Outlet-Inlet, and Inlet-Outlet

If by directional volume displacement you mean a rotational component to an inlet velocity, then yes you can model that with Caedium. First create your axis of rotation and then apply the Angular Velocity tool from the Physics Tool Palette to your inlet. For an example see the Angular Velocity Condition for the Rotating Wheel section in the tutorial "Flow Over a Rotating Wheel with Moving Ground." Although the Angular Velocity condition in the tutorial is applied to a wall the procedure to use it with an inlet is exactly the same.

The Outlet-Inlet and Inlet-Outlet conditions on the Physics Tool Palette can both deal with flow in or out of the simulation domain. However, you'll need to specify the inflow conditions in various ways. Try using the Inlet-Outlet condition and changing the Type property to see the various inflow specification options.

Hope this helps.