View Single Post
Old 08-13-2010, 07:07 PM   #9 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,268
Thanks: 24,393
Thanked 7,360 Times in 4,760 Posts
size

Quote:
Originally Posted by miket View Post
I thought that the 2.51 ratio is for a given height/maximum cross section. A shorter/narower but longer vehicle could have the same given volume and a smaller frontal area.
miket,the size of the streamline body doesn't matter,unless we're talking golf ball size.
The Cd will always be the same as long as it is at or above critical Reynolds number.
And as Dr.Hucho says,if it's shorter,like the New Beetle, or longer,like the Hindenburg, the drag will be higher.
What you're 'packaging' can influence the shape for sure.
If you build something like the VW 1-liter car,gen-1,or gen-2 it will have higher drag than the 'template' form.Cd 0.15/0.195 vs Cd 0.10.
I guess the deal is,define your needs,then shrink-wrap the smallest sleekest envelope over it.Remember safety.Don't scrimp on crumple-zone and such and wind up at the trauma center if you get popped by Barbie & Ken in their Romancemobile.
  Reply With Quote