Quote:
Originally Posted by stillsearching
Reading various articles on how streamliners, when touching the ground, have worse fuel efficiency than they do in free air - ie http://ecomodder.com/forum/attachmen...1&d=1247946422 (ie the half body at ground plane is over 2x as bad as the streamliner in free air) and having seen a solar streamliner body design that I can't find a link to right now, but which had like a 0.09 coefficient of drag not by hugging the ground but by letting the air flow under it better (it may have been 12-15 inches up but it was also going very very slow like 20mph, i'd assume as speed goes up you'd need more clearance) i'm wondering at what point of height/speed/other factors it makes sense to start letting air flow under the vehicle again?
Low ground clearance is hard to drive with in a world of speed bumps and potholes. And some of my projects wanting to be based around pickups tend to sit up higher already. When is the belly pan and a lift better aero than a ground effects kit and lowering?
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*All bodies essentially 'double' in drag when in ground proximity.
*The half-body,without wheels, would be as low as Cd 0.08 vs 0.04 in free-flight.
*The GM Sunraycer was measured at Cd 0.089 in ground effect with wheels and wheel fairings.NUNA solar racers are in the Cd 0.07 range (You must consider how a motorist would get in and out of such a 'car.'
*If you look at Hucho's drag tables you find that a conventional motor vehicle would require an 11-foot ground clearance before significant drag reduction could be affected.
*From research published on the lowest drag,highest fuel economy concept cars constructed,the car is lowered with active suspension and raked for lowest drag/frontal area/low C.G./favorable C.P.(this concerns a real-world 'door-slammer' which a motorist could walk up to,open a door,get in or out unassisted).
*Aside from Bochum University's current solar racer,most other 'cars' require a crew to assist the driver's ingress/egress.