Quote:
Originally Posted by Nerys
every time when I whip out the camera and that flash goes off the rage CEASES instantly. and I mean like a twig snapping BANG rage gone. They turn tail and go away.
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Maybe they thought it was a muzzle flash. Maybe they turn tail thinking, "Whoa, I'm not going up against a professional road rager, he's got a silencer and everything!"
Anyway, back to our subject: Aerodynamic lift - A real problem
Quote:
Originally Posted by Nerys
...but that lift is STILL adding drag.
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This thread has metamorphed in an interesting direction. It started as a discussion of lift as a safety issue (the consensus was it's not a major factor at ecomodding speeds), now it's about lift as a component of aerodynamic drag.
Nerys:
> if any lift causes drag THEN ALL LIFT causes drag.
MadisonMPG:
> I still think that lift hurts MPGs.
Frank Lee:
> The very act of creating lift, creates drag.
If we put it to a vote, it looks like we'd conclude that all lift causes drag and we should strive to get lift down to zero. Here's my take on it; please consider me the Loyal Opposition rather than a troll.
I think there's an optimal Cl for minimum Cd for every solid body, but it's different from body to body and it's different from environment to environment, and in most cases, optimal Cl is other than zero.
In free space the optimum shape is a symmetrical three dimensional teardrop at zero angle of attack and a Cl of zero, but cars don't drive in free space. I think in the ground effect environment, a teardrop is no longer the lowest drag body, and as the body gets closer to the ground, the optimum shape gets flatter on the bottom. It is no longer symmetrical and its lowest drag angle of attack is no longer at Cl 0.0
Asymmetrical airfoils which have Cl > 0.0 at Cd min are the rule, not the exception, as has been reliably demonstrated in wind tunnels since NASA was NACA. From the aerodynamic drag standpoint, too much lift is worse than too little lift, but some lift is better than no lift.
(note: while I was typing, winkosmosis was posting--I guess this post is a wordy version of: +1 what winkosmosis said.)