Quote:
Originally Posted by InsightfulRay
I took that sentiment quoted above to heart and applied a set of vortex generator tabs to the roof and rear seat side windows of my Mini. I applied a total of 14. Eight on the trailing edge of the roof and three on each of the two rear seat side windows.
I'll post results when I accumulate a few tanks of driving with them. So far, I've noticed the rear glass and hatchback appear to be staying cleaner than before. That's a welcome result.  |
I'm interested to hear how the comparison goes. From what I've heard so far, a clean separation at the back of the car is better, and "energizing the boundary layer," like vortex generators do, essentially gives up a laminar boundary layer in order to make the boundary layer more reluctant to separate from the surface.
So, it'd be applicable mainly where the angle between the roof and the back window is steep enough that you get separation, but shallow enough that some vortexes would make the air cling better. Not so much applicable when there's nothing behind them to cling to.
When Autospeed did an informal test of trailing-edge VGs on an Insight, they made fuel consumption worse:
Browser Warning -- and there's an old thread here taking all that into account, and looking for hard data:
http://ecomodder.com/forum/showthrea...nefits-97.html
That thread points out that tank to tank testing may not help, although some A/B drag tests would be cool.