CFD: Pressure loss over an engine valve
 

Hi,

I'm trying to model the flow through a valve port and around an engine valve into a cylinder chamber, which flows around a wide piston rod/trunk (like an annulus). Specifically, I'd like to know the pressure loss as the fluid moves around the open valve and enters the cylinder.

I'm having trouble defining a mesh around the valve CAD geometry (inside the valve port and around the head into the cylinder) as it is open space. I'm quite new to ANSYS, does anyone know how I'd do this?

If you imagine you had to simulate flow around a pencil inside of a hollow tube, which connected to a hollow cylinder, how would you mesh that fluid domain?
Thanks.