View Single Post
Old 06-13-2018, 11:50 AM   #730 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 9,132
Thanks: 12,710
Thanked 4,808 Times in 2,747 Posts
likely be less

Quote:
Originally Posted by Tesla View Post
So then I assume if we design the curve to 23 degrees to depart the body at the 80% mark that would be within the parameters and this would also mean that the overall principle would likely be less than the std 1.78 tail ratio.
I had a graphic for Buchheim's Cd 0.14,long-tail,VW Flow body that I generated from a nested diagram presented by Hucho.It was in my PhotoBucket account and I've lost the ability to share over 700 images.Sorry!
It would be the best 'explanation' for what Buchheim and his team came up with.
The '23' degree slope does imply that we could cheat on the length of the aft-body a smidge,but you'd want to have a look at the flow body before you passed judgement.
While Hucho also presented Mair's 22-degree 'solution' for attached flow,we could take 23-degrees as the absolute maximum slope (given a proper streamlined leading transition) which guarantees flow attachment.
Since members may invest in the neighborhood of 800-man-hours to create a streamlined fairing,I thought that 22-degees would be a safe insurance policy.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote