ANSYS CFD Fluent

Created by Ananth Narayan on 4 September, 2018

How to preform a CFD simulation/model is a internal free space within the component volume.

Hello, Please excuse me as this is my first question as a new arrival to grab cad.
What I am trying to learn is that of running an ANSYS Fluent simulation of the likes of a heat exchanger as part of a larger piping system, I have done a couple before but I had to draw the internal volume independent of the component to model, I think I am missing maybe one or two steps to do this, that would be identifying the internal volume to model and setting the appropriate boundary conditions.
I have the ANSYS FLUENT Tutorial Guide Release 18.0 January 2017, and thus far I cannot find the critical steps that I have missed
any advice would be greatly appreciated.
Thanks...