Fluent is a computational fluid dynamics analysis package. The solid models are "designed" in a package like Catia or Unigraphics and the geometry can be exported to CFD packages for aero analysis and FEM packages (Abaqus, DYNA, etc) for stress analysis.
Are we talking about mechanical simulation? There are a lot of finite-element-type packages (i.e. ANSYS, ABAQUAS, etc.) that can simulate when and where your wing is going to fall off.
Are we talking about aerodynamics? I remember a previous thread talking about the CFD packages used by different teams (Fluent, Star+CD, others?)
(One of the next big things is combining these two into FSI (Fluid-Structure Interaction) modeling) Ansys bought CFX (another CFD company) so it sounds like it's being worked on.
In Racecar Engineering I've read about lap simulation software, engine/cam/valve design packages. I remember reading in a magazine (about sensors) that there's about 2MB of telemetry data every second available. So with all this data available there's almost no end to the different models that can be generated/validated/improved.
-Skrat