The body shape of minimum drag

[Grant-53]

There are two SAE papers and two shapes being discussed. The earlier 1976 model was featured in Popular Science that year. The car was to be somewhat adaptable to a Fiat 131 and compared to the Chevy Citation. Image such a car with a 3 cyl. turbodiesel. The newer shape (Aptera) has potential as a fairing for a long wheelbase recumbent bicycle.

[ERTW]

I don't know where else to put this (and I'm too lazy to check). It's from another paper. I know Aerohead has shown a graph of Cd versus backlight angle. The quadratic equation is:

y = 0.7762x^2 - 0.2612x + 0.2502

y is in radians

If we recall high school calculus, to find the minima, you differentiate, and equate to 0. Short answer = 30.276* (from the horizontal). hth

I may quote the original Jaguar SAE papers where I found this info. 2008-01-0737