Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-31-2008, 11:42 PM   #1 (permalink)
Master EcoModder
 
roflwaffle's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 1,490

Camryaro - '92 Toyota Camry LE V6
90 day: 31.12 mpg (US)

Red - '00 Honda Insight

Prius - '05 Toyota Prius

3 - '18 Tesla Model 3
90 day: 152.47 mpg (US)
Thanks: 349
Thanked 120 Times in 79 Posts
How loose is too loose?

Someone, I think treb but can't remember atm, mentioned that a loose cover for a boat tail could be as bad as none at all, and I was wondering, what constitutes loose? Based on internetz searches, it seems like oscillation may not be a bad thing for separation, especially if actuated, so how much give can a surface have before it becomes relatively useless compared to a rigid surface?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-01-2008, 10:08 AM   #2 (permalink)
Master Novice
 
elhigh's Avatar
 
Join Date: Jan 2008
Location: SE USA - East Tennessee
Posts: 2,296

Josie - '87 Toyota Pickup
90 day: 33.51 mpg (US)

Felicia - '09 Toyota Prius Base
90 day: 51.23 mpg (US)
Thanks: 416
Thanked 598 Times in 438 Posts
Huh. You mean like a luffing sail, where the vortices are still following a surface? Tricky to model.

I think it would set up one helluva racket inside the car. For my money, loose at all is too loose - there's squeaks and clunks enough without adding more.
__________________




Lead or follow. Either is fine.
  Reply With Quote
Old 04-01-2008, 10:05 PM   #3 (permalink)
Master EcoModder
 
roflwaffle's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 1,490

Camryaro - '92 Toyota Camry LE V6
90 day: 31.12 mpg (US)

Red - '00 Honda Insight

Prius - '05 Toyota Prius

3 - '18 Tesla Model 3
90 day: 152.47 mpg (US)
Thanks: 349
Thanked 120 Times in 79 Posts
Not exactly. I'm just wondering if using, say, thick clear vinyl, which will have some amount of play/give to it even if it was fairly taut, would be significantly worse than something solid.
  Reply With Quote
Old 04-02-2008, 12:05 AM   #4 (permalink)
EcoModding Apprentice
 
Join Date: Dec 2007
Location: Ventura, Ca
Posts: 112

Whoop's Wheels - '89 Honda Civic Wagovan
90 day: 39.09 mpg (US)
Thanks: 1
Thanked 9 Times in 7 Posts
Not having done anything in clear vinyl, it is a little tough to say. However, my quess is that your not going to be able to get it tight enough to keep if from flapping and when it goes into flapping it will be extremely annoying, at best. I'd recommend using something more rigid, but it just a suggestion.
  Reply With Quote
Old 04-04-2008, 01:32 PM   #5 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 11,760
Thanks: 18,958
Thanked 6,092 Times in 3,736 Posts
looseness

My thought is that if the shape of the envelope is such that it is "just" maintaining attached flow,that if it moves or deforms to a contour that exceeds what the flow will follow,that flow will separate,defeating the whole premise of the tail.My inflated boattail on the T-100 had an aluminum band that held the envelope to a cantilevered bottom spar,which prevented either vertical or lateral displacement.Air pressure inside the envelope provided enough skin tension that it performed as a "solid" surface.Tuft tests demonstrated attached flow over the entire surface.

__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com