dear all I wish to analyse the lift and drag of a rocket nose cone travelling at Mach 3.6. What is the best way to set up a 3-D Fluent model to accuratly determine the forces acting on the nose cone? Thanks in advance.

A few things that I'd do: Use absorbing Riemann-based boundary conditions - Fluent calls them "Far-Field" boundary conditions. Use the coupled solver. Use a turbulence model which doesn't go crazy in shocks and other regions with strong acceleration/deceleration, ie don't use the standard k-epsilon model.