Gurneys increase the pressure on the pressure side and decrease the pressure on the low pressure side.

To my understanding, it does so by creating more turbulence near the trailing edge which in turn lowers the boundary layer thickness.

In order to maintain L/D, gurney should be no more than 2% of the chord length.

Hopefully BKL can chime in.

-Dino

 

Thanks for clearing up my misconecption Dino!

 

Antonov has it right.

A gurney slows down the air ahead of it, increasing the static pressure on the upside of the wing. It also adds a pair of vorticies directly behind the flap which is often associated with a drop in pressure, which in turn maintain flow attachment on the bottom side of the wing.
So a wing can have an even higher angle of attack, or camber, without flow separation when a gurney is installed.

 

^^^^ what if you use a low AOA, is the wing performace (downforce,drag) better with, or without the gurney flap?

thanks

 

Even with a low AOA, the wing will produce greater downforce with a gurney. This is because the gurney is still slowing down the air ahead of it which increases the static pressure on the wing's upside.

 

thanks for the prompt reply

 

Will a 1500mm width handle as well as 1600mm?? Any advice appreciated

 

less drag, and less downforce, depends on your setup (front aero)

 

the visualization



and how it helps

 

type 2 is on order now, looking forward for it!!!