View Single Post
Old 05-22-2019, 12:41 PM   #15 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,508
Thanks: 16,287
Thanked 5,590 Times in 3,342 Posts
2D vs 3D

Quote:
Originally Posted by kach22i View Post
The last two posts ask some very good questions.

Aerospaceweb.org | Ask Us - Wing Vortex Devices


May 15th 2019
BAE Systems 3D printing enables first ever flight using supersonically blown air
https://3dprintingindustry.com/news/...wn-air-155452/



The thing to perhaps keep in frame of mind is the squeezed high velocity air trapped under the car once liberated from it's confines will slow and expand and increase in pressure very rapidly, hence causing trailing drag behind the car.

What ever one can do to delay or mitigate this disruptive transition should help lower aerodynamic drag.

I just don't see these tiny shark fin devices located where they are having much of a chance to do that but welcome viewing any CFD or wind tunnel images anyone can come up with.
Hucho mentioned and emphasized that, never has a 2d flow device ever lowered the drag of a 3D body.
And history has shown that a simple low drag body is the best way to achieve low drag.They're not as 'sexy' as a race car,their just faster and more fuel efficient.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote