A Quick Post on Why Cars Go Airborne

A quick post for my friend, @TheOrangeCone that I’ll expand on later (I have theater tickets tonight!)

@TheOrangeCone asked why Kurt Busch went airborne in the Talladega crash.  The answer is the same for all the cars that end up in the air:  when a car rotates (so that its side or its back is leading instead of its front), it looks an awful lot like an airplane wing — a shape that is optimized to generate lift.

If you have an isolated car rotating, the roof flaps deploy and that’s usually enough to keep the car on the ground; however… if you look at the video from Talladega, you see that the 36 hit Busch at the right rear quarter panel.  That pushes air under the car and the combination of the mechanical lift and the aerolift sends the car up in the air.

How do you fix this?

1.  Get rid of restrictor plates so that the cars aren’t operating in such close proximity to each other and the drivers have more throttle response.  This would need a new engine design and would eliminate pack racing, so it’s not a popular idea with many fans or with the engine companies that would have to do something totally different.

2.  Drastically change the car’s shape to make it much draggier to slow the speeds and make the car look less like a wing when it rotates.  After having fans gush about the identity of the Gen-6 cars and how they look more like their street cousins, neither NASCAR nor the manufacturers are likely to be very excited about sticking something on the car that looks nothing like anything on a production car.

3.  Come up with an active device – the roof flaps are passive.  They work on a pressure differential  (explained in the video below) and they just fly up.  Something that would be more like the flaps that an airplane deploys when it is time to land could be used — but you have to figure out a mechanism for it to deploy at the right time and then be out of the way the rest of the time.

The true answer to “how do you keep cars from going airborne” is that you have to slow them down.

More on this before long.  I’m headed out to the theater…

1 Comment

  1. Great demonstration Diandra. Clearly understood and I have only a minor degree in Mechanical Engineering. If a driver holds a major degree in ME, looks like he would understand also. !!!

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