mark kibort

http://www.youtube.com/watch?v=3EjFkPL_H_4

Speedtoys

Sweetness.
Thanks..breaks the boredom here at Sears Pt this weekend.

bronto

Interesting the way the air flows UNDER the rear wing; you'd think it would cause lift, not downforce.

Speedtoys

As an inverted wing..you want the higher velocity airstream flowing under the wing...so this is a well functioning inverted wing.

At the VERY end of the video, you see the wing vortices flowing from the high pressure above the wing, to the low pressure under it, going over the edge counter-clockwise...it would be CW on the right side of the car.


Heres what they look like on airplanes..as the high pressure air UNDER the wing rolls around the edge of the wing to the top CCW..but on the right side of the plane. It would be CW on the left side. Wake turbulence will blend a small plane.

http://www.youtube.com/watch?v=uy0hg...eature=related

Winglets at the edge of a wing help reduce this loss of lift down and the resulting turbulence

Mrmerlin

Thats an interesting video..

Bronto I dont understand your post??
the fastest air velocity would be under the rear wing.
This air would also be moving faster than the car was traveling.
Lets say the car is moving at 100mph the air would be going over the top of the wing at 100mph but going faster on the underside of the wing, due to the longer distance to travel along its curve
This speed differential would then decrease the pressure
( compared to the topside of the wing) under the wing resulting in a downforce being applied to the chassis..

NOTE the rear wing on this car is upside down compared to a wing on an aircraft.


Or said another way the cars rear wing is similar to horizontal stabilizer/elevator on a conventional aircraft, both supply down
force depending on their angle of attack

NOTE the wing tip vortices coming off of the rear spoiler will spin in the opposite directions of an aircraft wing,
as the higher pressure is trying to reestabllish with the lower pressure

Video of wing tip vortices.
http://wn.com/Wing_tip_vortices_behi...ing__Wakesheet

IcemanG17

great thread

Since wind tunnels are massive $$$$ there has to be a way to come up with a cheaper version....for some reason I keep thinking a leaf blower with a jet from a theater fog machine would work..oddly enough I have BOTH....MK...I think we might have a project???

Speedtoys

PorkenTunnel.

Some assembly required, and 1/2 acre of available open space.

bronto

Yeah, I've read some stuff on how lift works, and it's all over my head. I take some comfort in also reading that physicists also don't completely understand how it works.

tv

that was interesting, this one has a little to do with aerodynamics and is more fun to watch

http://www.youtube.com/watch?v=NuE6eRPP7qY

NoVector

Mrmerlin - I think his point is, it looks like ALL the air is going under the wing--so it negates the high/low pressure on one side (or the other). In this case, wouldn't it really be "reverse lift", meaning, the pressure is lower on the bottom of the wing... the opposite of an aircraft wing with low pressure on top causing lift. Nevertheless, would be neat to see this on a 928--especially, an OB

Speedtoys

Of course, we know that not ALL of the air goes under the wing, just THAT tiny slice of air was directed there.