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Old 08-28-2010, 04:38 PM   #93 (permalink)
aerohead
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VGs

Quote:
Originally Posted by 3-Wheeler View Post
Do you think vortex generators in this spot would help keep the air attached longer?

The angle on the under body smoothing panels is 6° leading to this spot, and the exit angle is set to 12.5° or so.

Since the exit angle is so abrupt, would vortex generators help with attached air flow?

Jim.
Jim,I'm gonna guess and say 'probably not'.The reason being that unlike the side and top flow,there is no free-stream below the ground to feed kinetic energy into the boundary layer of the diffuser to delay separation.There's no 'up-wash',only side air spilling into the void which will impart some energy,how much,who's to say? There's so far no investigation of such a thing.
Here's the caveat.I would suspect that the faster more energetic side flow will want to twist into an attached vortice as it collides with the moribund underbody flow.Turbulators could help to dice up this flow,give you a uniform separation point and produce small eddies rather than larger votices,maybe for an overall drag reduction.Just a guess.
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