Hi there, I'm pretty new at using Fluent so this question is going to be very general. I'm trying to model flow through a 2D nozzle. I'd like to be able to calculate the flow rate through the nozzle as a function of the pressure difference between the inlet and outlet. I'm not dealing with large pressure differences so this is a subsonic nozzle. Thanks for the help.

You have to define boundary conditions as "pressure inlet" and "pressure outlet". Flow rate can be monitored at Report-Fluxes...Or since you are dealing with incompressible flow you can monitor velocity at outlet (Solve-Monitors-Surface...)