View Single Post
Old 04-24-2020, 04:27 PM   #49 (permalink)
COcyclist
Aero Wannabe
 
COcyclist's Avatar
 
Join Date: Dec 2007
Location: NW Colo
Posts: 738

TDi - '04 VW Golf
TEAM VW AUDI Group
90 day: 52.55 mpg (US)
Thanks: 705
Thanked 219 Times in 170 Posts
From another thread Hubcaps, taped smooth vs none...

Quote:
Originally Posted by aerohead View Post
Fuji researched wheel cover drag with respect to their Subaru XT.
*The ventilated flat disc,when taped closed,revealed a delta Cd 0.002,for an overall drag reduction of 0.69% (and no brake cooling).
--------------------------------------------------------------------------
John Shinella,of Pontiac styling, researched wheel cover drag in the Lockheed Marietta wind tunnel during development of the Trans Am Firebird of 1982.
*The car,@ Cd 0.32,with no covers
*with ventilated flat discs dropped to Cd 0.296
*TAPING over the vents produced Cd 0.290
*Shinella's ventilated convex covers showed Cd 0.287
--------------------------------------------------------------------------
So,taping was good for delta Cd 0.006,which cut overall drag by 2.02% (a 1% increase in mpg @ 55-60 mph).
--------------------------------------------------------------------------
The difference between no wheel covers,and Shinella's covers is a 10.31% overall drag reduction.(5% MPG @ 55-60 mph).
A set of MOONs would come in at a little lower drag and mpg increase.
I get confused with these two GM designers. John Schinella designed the Trans Am but I thought it was Larry Shinoda that did the aerodynamic studies. I couldn't find it in a quick search.

Interesting reading https://bangshift.com/general-news/c...ohn-schinella/
https://books.google.com/books?id=3t...namics&f=false

*Shinella's ventilated convex covers showed Cd 0.287

I do not have that paper but the way I read this it looks like the ventilated convex covers have lower drag than the TAPED covers. Am I missing something?
__________________
60 mpg hwy highest, 50+mpg lifetime
TDi=fast frugal fun
https://ecomodder.com/forum/showthre...tml#post621801


Quote:
Originally Posted by freebeard View Post
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.

Last edited by COcyclist; 04-24-2020 at 04:45 PM..
  Reply With Quote