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Old 06-17-2017, 01:16 PM   #19 (permalink)
Vman455
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Quote:
Originally Posted by gumby79 View Post
15° off the direction of flow (not travel) this will require testing before installing.
The top/tip must reach up above the boundary lair into free flow to be able to pull it were you want.
you tube link. Velox Motorsports FRS / BRZ Diffuser Flow Visualization Testing
This will be better than oil , easyer to clean up . They used" China Wight clay "and water.

Zig zag ... my theory is that they are trying to cause counter-rotating vortices. Instead of co-rotating vortices. I dont know witch is better , this may be application specific.

As for use look at the Mitsubishi Evo, top of the back window VG's were used to reduce instability caused from separated air (due to the back glass angle and a trunk too short to allow for reattached boundary lair)
buffetting the back end reducing the safe top speed
Mitsubishi's paper indicated the VGs on the Evo were used to reduce the Cd of the car overall and improve the effectiveness of the rear wing. The new Civic Type-R does the same:



Compare to the base Civic hatch, which uses a slotted spoiler to keep flow attached to the (too-steep) rear glass:

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