Quote:
Originally Posted by CFECO
I may have missed something along the way? Why do F-1,Top Fuel and Indy cars have small pointy noses which taper up to the cockpit "section" diameter, rather than the "Template" shape? Anyway, here is an interesting "car" I found along the way, and the back of a Pontiac Aztek doesn't look so bad after all!
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*Indycar and F1 cars momentarily approach the transonic region where supersonic shockwaves can appear over minor portions of high-acceleration regions.
* Super-sonic drag is ruled by shockwaves and a 'pointy' nose helps mitigate this.
* The 'pointy' nose also has less cross-section which means more air to the front splitter (wing),which can win or loose the Indy 500,as just happened to Danika Patrick.
* All this allows maximum use of whatever the rulebook allows each season,whether wings,splays,strakes,chines,deflectors,ground-effects tunnels,slats,flaps,fins,or what have you.
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* Indycar/F1,wind tunnel tested in the 1980s demonstrated the following:
* Basic body = Cd 0.25
* Body with tires = Cd 0.54
* Body with tires and wings = Cd 0.97-1.17
Not much help to aero-modders!
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*Top-Fuel dragsters ARE operating in the transonic regime,their 'pointy' noses,like the F1/Indycar are also doing double-duty,managing shockwaves,and allowing the maximum volume of air to the front wing,to prevent blow-over,potentially lethal at those velocities.
* The point also allows perfect triangulation of the tube chassis,with minimum mass,high rigidity,strength,improved power-to-weight ratio.
* The 'wedge' guarantees attached,ram-flow to the engines bug-catcher.
* Once the air goes beyond the engine it is basically full separation.Dragsters have the highest drag of all race cars,often exceeding the Cd of a parachute,except for Jocko,and the Arivett Brother's streamlined dragster.
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* As to the Pontiac Aztek,do you have some specific data or information about its aft-body that you'd like to share? Frank Lee's been looking at this one.I know he and the rest of us would appreciate it.Thanks
