Quote:
Originally Posted by AeroMcAeroFace
Doing some calculations it seems that aerofoils of over 100 times lift to drag are common, and given a rolling resistance of 0.01 the difference between lifting using wings and using wheels are identical, so theoretically adding wings would have no effect on total drag.
But with greater than 100 times lift to drag then it is potentially beneficial to add wings.
And if the car is already shaped like an aerofoil, such as a solar car, then most of the lift induced drag would already be there in the shape of the car.
Those are in free air and ground effect may change those things.
But the car has to exist, making that shape have lift would give very little extra drag because the shape is already there, already generating drag.
(I do know about the ultra low rolling resistance tyres that they use on solar cars, but you can't buy those and they only last for 200 miles)
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I would mention that an airfoil-shaped car is not a guaranteed prerequisite for lift. All wings exhibit a zero-lift angle-of-attack.
And if you think about it, as long as the air continues to follow the streamline contour of the airfoil, it is simultaneously generating higher local pressure.
If the flow remains attached all the way back, then all local barometric pressure is present at the rear stagnation point, minus the skin friction, lost in the turbulent boundary layer (nothing we can do anything about).
The pressure of forward and rearward stagnation essentially cancel any lift due to acceleration at the suction peak of the body.
Static axle loads are sufficient for perfectly acceptable stability.