Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-25-2009, 04:04 PM   #1 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 19,799

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

ForkenSwift - '92 Geo Metro EV
Last 3: 95.68 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 50.45 mpg (US)
Thanks: 2,177
Thanked 4,979 Times in 2,509 Posts
BMW tests delta / strake style roof mounted vortex generators

You saw it here first, folks!

While perusing the photos of BMW's new wind tunnel facility, I happened to notice the strakes on the top of a 3-series model being smoke tested on their rolling road:



Oooh!

OK, yes I'm being a bit facetious... people seem to latch on to VG's as a magic bullet, and they're not. Remember: when optimized by Mitsubishi, they estimated delta style VG's made a difference of -.006 to the drag coefficient of the Evolution sedan.

-006 is nothing to sneeze at, don't get me wrong. But it's not a magic bullet, and a change of that magnitude won't show up in either tank-to-tank or controlled-as-possible testing:

I think what's MUCH more significant from BMW's testing is the full set of four fender skirts that automatically cover the 3-series wheel wells after it jettisons the wheels and enters flying mode:




Attached Thumbnails
Click image for larger version

Name:	p90048195-1280x768-655x436.jpg
Views:	36
Size:	42.9 KB
ID:	3762  
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-25-2009, 04:34 PM   #2 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 32 Times in 25 Posts
Interesting setup, with the wheels being a part of the facility. What happens if the guy falls onto the treadmill? Looks like precarious footing on that smooth ledge...
  Reply With Quote
Old 06-25-2009, 05:39 PM   #3 (permalink)
Master EcoModder
 
tasdrouille's Avatar
 
Join Date: Jan 2008
Location: Mirabel, QC
Posts: 1,672

The Guzzler - '08 Hyundai Elantra GL
90 day: 33.12 mpg (US)

Got Soul? - '11 Kia Soul 2U
Thanks: 35
Thanked 80 Times in 52 Posts
This thread is useless without a research paper :P

Cool though. I'd like to see some numbers, but probably half a point at best, highly dependent on chord placement.
__________________



www.HyperKilometreur.com - Quand chaque goutte compte...
  Reply With Quote
Old 06-25-2009, 06:13 PM   #4 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 8,401
Thanks: 10,405
Thanked 4,427 Times in 2,461 Posts
elegant

Elegant way to separate aero from combined aero/RR drag.-------- Does the large ground clearance in the second photo confirm rumors of BMW's upcoming Monster-Series?
  Reply With Quote
Old 06-25-2009, 11:03 PM   #5 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Quote:
Originally Posted by winkosmosis View Post
Interesting setup, with the wheels being a part of the facility. What happens if the guy falls onto the treadmill? Looks like precarious footing on that smooth ledge...
Laser Beams, man... Laser beams.

I was actually wondering the same thing... I bet there's a "hey, there's weight in the wrong place!" sensor that shuts it off or something.
__________________
"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 06-26-2009, 01:58 PM   #6 (permalink)
Master EcoModder
 
Join Date: Mar 2009
Location: Northeast Ohio
Posts: 268

The Wife's Hot Rod - '09 Pontiac G8 GT
Last 3: 23.22 mpg (US)

Big Outback - '13 Subaru Outback 2.5i

Little Outback - '02 Subaru Impreza Outback Sport
Thanks: 0
Thanked 16 Times in 16 Posts
Hopefully the dorks turned off the rolling road when the car was up in the air.

Lots of testing on race cars has the wheels not attached to the car. So you can tell the aero load on the wheels & this way you don't have to build scale suspension systems.
The car is rigidly mounted so you can measure the pitching moment generated by the body. The body itself won't pitch though.

I am guessing that they are using the wind tunnel they use for their F1 cars.

Don
  Reply With Quote
Old 06-26-2009, 02:18 PM   #7 (permalink)
EcoModding Lurker
 
Join Date: Feb 2008
Location: Nuevo Mexico
Posts: 26

Speedster - '69 Schwinn Speedster
Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by MetroMPG View Post
I think what's MUCH more significant from BMW's testing is the full set of four fender skirts that automatically cover the 3-series wheel wells after it jettisons the wheels and enters flying mode:



Ah Ha! so at least BMW is finally admitting to having flying cars! When do they appear in the showroom?

__________________
- Cool. Practical. Sustainable. EcoDaddyo.com -
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com