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Old 01-03-2013, 01:17 AM   #20 (permalink)
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Originally Posted by wmjinman View Post
This same Tom Burkland I just mentioned (who also happens to be an aeronautical engineer in his "day job"), designed and built a "competition coupe" before he got into the streamliner project. Interestingly enough, this old competition coupe was bought by a guy here in Carson City who still races it. When I learned the aerodynamic design of it (and I was allowed to lay down next to it and look at the bottom), it just blew my mind. Tom designed it as an upside down wing!! It's higher from the ground at the tip of the nose, then slopes down closer in an airfoil curve to a minimum somewhere underneath, then back up towards the tail. Tom's theory; downforce without drag (or any more drag than a wing).

I just couldn't believe it. "What about the air you're compressing underneath?!?!?! You've GOTTA be causing LIFT!" Not so. The air accelerates under the car just like it would over a wing, producing a low pressure area under there. "But what about the air 'trapped' between the car and the ground?" I asked. The answer: no air is "trapped" - it's flowing under there, and the ground is just the opposite side of the venturi throat. It has to accelerate, causing the pressure to DROP. At about that time, my poor little brain began to smoke and I had to stop thinking!!!!

But it worked. Dan (Dan Webster, the car's current owner) routinely holds multiple land speed records with that car powered by vintage flathead Fords. I think he's right at 200 mph. And when Tom Burkland was racing it, he was hitting 300 mph with small block Chrysler engines. Weird, huh?

So the lesson I learned: Aerodynamics is a lot more complex than I thought it was!! LOL!!
lol, that's called ground effects. The effect is more pronounced because the "bump" gets very close to the ground, and the air doesn't have anywhere to go, whereas on a wing there's the rest of the sky in place of the rigid ground.
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