fenders vs. no fenders
fenders vs. no fenders
(OP)
which one is more aerodynamically efficient? and no speculation, either. I have a friend that says that no fenders are more efficient cause of more surface area, and stuff, while I can swear I remember reading about an aerodynamicist who said that open wheel designs are inferior because the 4 protruding wheels disturb the air flow severely. anyone know?
Joseph.
Joseph.





RE: fenders vs. no fenders
more surface area = more drag
The only example I can think of with fast cars with no fenders are the F1 cars, and they're not meant to be fast in a straight line, they're meant to take corners at 3 Gs of lateral force, stop HARD and accelerate fast, and the best way to do that is to get rid of all possible weight.
seriously fast ground vehicles like jet powered cars for record attempts have wheel fairings (or fenders if you must) over their tires or wheels, that is if their wheels are exposed at all. Your friend has little common sense IMO.
RE: fenders vs. no fenders
jetmaker
RE: fenders vs. no fenders
RE: fenders vs. no fenders
Can't tell if that is an actual question, or you are just pointing out that most airplanes retract their wheels to get them out of the airstream.
Anyways, it is a good point to show why most airplanes try to have retractable gear. The tradeoff in performance is often weighted against expense, weight, and system complexity.
jetmaker
RE: fenders vs. no fenders
Take it into the bush, and the fairings get clogged with mud.
RE: fenders vs. no fenders
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Also note the huge flares on the Caterham shown here, which add to the drag:
h
RE: fenders vs. no fenders
You can do silly things to a design, e.g., use a flat-front box for a fairing, which will result in cruddy performance even relative to a naked wheel. You can use a bicycle racing wheel, which will probably beat any fairing you might try to design for it.
That said, you can clearly relate a normal tire to the standard ball-nose projectile with a flat tail, and a fairing to a high performance ogive nose and boat-tail projectile and guess what, that larger frontal area ogive and boat-tail wins by a wide margin, because it does a substantially better job of reducing flow separation and drastically cuts Cd, while the tire has a Cd that's nearly 1. That's why there are no blunt-nosed supersonic ammunition.
TTFN
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