View Single Post
Old 01-20-2014, 06:33 PM   #35 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,267
Thanks: 24,392
Thanked 7,360 Times in 4,760 Posts
separation

Quote:
Originally Posted by 3-Wheeler View Post
I think that in the case of the wagon shown, there is a steep and rapid transition between the windshield glass and roof top. I would think that there would be air separation there and that it could be handled by building up the roof slightly.

Take a look at the Kia Soul. This roof has an incredibly sharp transition in that same area. Then take a look at a Prius or Gen 1 Insight and see how much "smoother" this transition is.

"Flow has to be attached at the front for the tail to make any difference."

Jim.
Hucho talks of 'saturation',and that once the radius of the leading edges will support attached flow,that there's no further drag reduction with increased softening.If the windshield/roof intersection is as rounded as the hood/grille intersection,it seems like it should be plenty,if Hucho's shooting straight with us.Both of these areas are in a favorable pressure gradient,with the oncoming flow tending to hold the boundary layer against the body.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote