View Single Post
Old 03-05-2016, 01:17 PM   #43 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,391
Thanks: 24,469
Thanked 7,409 Times in 4,800 Posts
undertail

Quote:
Originally Posted by cyclopathic View Post
Also the tractor trailer aerodynamics are quite different from modern hatchbacks. They are tall and narrow, and have high % of airflow on the sides. Hatchbacks like Prius C have more air flowing over the top. Mitsubishi Mirage even have A-pilars spread out and uses windshield rain grooves to redirect flow over the roof. Observing C in the drizzle tells similar story, but may be not to the same extend.

If you think getting 38 MPG at 73mph is sweet, regular Gen3 Prius was getting about that much at 80-85mph going up 4% slope on I-40 in NM, abait at higher elevation and warmer temperatures. Just another testimony to efficiency of longer body and Kammback design.

I am seeing more and more new cars (Toyota, Subaru, GM) which incorporate VGs into trailing edge of undertail belly panel. Are they really helpful or they just easy to mold?
My opinion is that these are just a styling gimmick.The strakes add reinforcement to the otherwise flimsy valance panel,providing some structural stiffening to prevent flutter caused by the wake.
I've seen Lincoln Continentals and Town Cars who's rear bumper facias would 'tremble' at highway speeds,revealing aeroelastic deformations caused by the wake turbulence/vorticity.
Automakers can change this area each year (along with the nose) at very low cost,giving buyers the impression that their 'new' car is 'different' from the previous year model.
You'll never see airplanes,airships,or submarines do this.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
The Following User Says Thank You to aerohead For This Useful Post:
cyclopathic (03-06-2016)