Perfection
I've been pondering on this for a while now and I think we are coming to the limits of this process, as I understand it we have experimental data and experience which suggests a teardrop type shape with probably a bit less than the 2.5:1 ratio as being the ideal. The risk being that the penalties accrue much more rapidly below 2.5:1 than above if something goes awry. Then there is the real world where appendages change the story whether you are a fish, bird or motor vehicle.
Unless we can determine any other specific mathematical relationships, without extensive testing it is hard to determine what the ideal distribution along the curve would be.
My personal thoughts are that something of an Scurve might be the ideal where the angles accelerate rapidly through to 7080% and then begin to taper back towards horizontal so that the converging air streams are aligned in a parallel manner. The Parametric equation had this characteristic, but any online search for teardrop equations will produce dozens of results, but which one is best?
