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I read a paper awhile back that reminded me of a few concepts and would love to run them by the group. Bare with me because I don't remember the majority of this paper, but I did highlight a few interesting things when I originally went through it.
idea: Co-rotating or Counter Rotating VG's, and Sub Boundary VG's (advantages)
idea: The use of VG's under the vehicle.
"The experiments claim that the vortex generator should be placed three (3) to ten (10) heights upstream of the separation line.......Vortex Generators submerged in the boundary layer give the best compromise between effectiveness in reducing separation and device-drag......" pg 14.
"... also reported that counter-rotating VG array can be as efficient as co-rotating arrays in preventing separation when the blade spacing is greater than three times their height." pg 15
"Compared to a single vortex case the circulation from each vortex is about 20% stronger... probably due to the impermeable constraint imposed as vortices act as mirror images of each other..." pg 15
"....show that small vortex generators are just as effective in preventing separations as the normal sized devices... low-profile VG's should be applied when the detachment point is relatively fixed and the VG's can be positions close the the separated region.... the maximum vorticity generated increases as the angle of attack increases for the small VG, but decreases with angle of attack for the large VG due to stall." pg 17 and 18
Logdberg, Ola. "Vortex Generators and Turbulent Boundary Layer Separation Control". Technical Reports from Royal Institute of Technology, KTH Mechanics; Stockholm, Sweden. October 2006.
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