[aerohead]

Originally Posted by julien.decharentenay

Thanks Mike. You can try SketchUp - there is a free version caller SketchUp maker and is reasonably easy to use.

To get things started:

- Cd = 0.8908

- Results and images at: https://aerodynamicondemand.appspot....1-4ef147317882
- Twitter @HibouSoftware

There is a vast amount of empirical data regarding the aerodynamic drag of differing geometric forms in the public domain dating back to before the turn of the 20th Century.
Some minimums have already been established for forms operating in ground proximity.Typically,streamline bodies of revolution and ellipsoids and their half-bodies return the lowest drag on a frontal area basis.
There are delayed-transition 'laminar' forms which can work with torpedos,submarine hulls,airships,wing sections,and fuselage,artillery projectiles and bullets,but they don't perform in ground effect.
Unless your CFD has 'Full Navier-Stokes' capability with the ancillary turbulence models built in,it will be unable to anticipate 3-dimensional wake forms behind road vehicle bodies,something critical to accurate CFD drag prediction.