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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-07-2018, 04:49 PM   #1 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2012
Location: Charlotte, NC
Posts: 134

TBD - '17 Toyota Corolla LE
90 day: 40.79 mpg (US)

Starship - '08 Toyota Prius
90 day: 41.57 mpg (US)
Thanks: 143
Thanked 110 Times in 47 Posts
Front inner fender drag reduction idea?

So I came across this concept today, one I had never seen before:


Found it in this document:

http://www.diva-portal.se/smash/get/...FULLTEXT01.pdf

Which compares full scale vs model (1/5th scale) in same wind tunnel. Results from above front inner fender concept are:

-.003 to -.006 drag reduction. (-.003 what the full scale model showed, -.006 what the 1/5 scale model showed)

Has anyone ever done/considered this?

  Reply With Quote
The Following User Says Thank You to woodstock74 For This Useful Post:
aerohead (09-08-2018)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-08-2018, 01:34 AM   #2 (permalink)
Moderator
 
Vman455's Avatar
 
Join Date: Feb 2012
Location: Urbana, IL
Posts: 1,935

Pope Pious the Prius - '13 Toyota Prius Two
Team Toyota
SUV
90 day: 51.62 mpg (US)

Tycho the Truck - '91 Toyota Pickup DLX 4WD
90 day: 22.22 mpg (US)
Thanks: 198
Thanked 1,797 Times in 937 Posts
What happens when the wheels turn?
__________________
UIUC Aerospace Engineering
www.amateuraerodynamics.com
  Reply With Quote
Old 09-08-2018, 05:52 AM   #3 (permalink)
Master EcoModder
 
Join Date: Jun 2016
Location: KY
Posts: 1,346

IGL - '04 Saturn Ion
Team Saturn
90 day: 56.19 mpg (US)
Thanks: 63
Thanked 364 Times in 268 Posts
I imagine that you’d momentarily lose the benefit of the ribs as you steer the car... what I’m curious about, however, is whether or not it’s important that the wheel gap be that tight... it looks almost as if the ribs are touching the tire... it wouldn’t be terribly hard to implement something like it on some of our old beaters though... (though for only .003 reduction in drag I’m not sure if it would be worth the effort)
__________________
My current Ecotec project...


My last Ecotec project...
  Reply With Quote
Old 09-08-2018, 08:10 AM   #4 (permalink)
Master EcoModder
 
Ecky's Avatar
 
Join Date: Dec 2011
Location: New Zealand
Posts: 5,005

ND Miata - '15 Mazda MX-5 Special Package
90 day: 42.54 mpg (US)
Thanks: 2,866
Thanked 2,501 Times in 1,547 Posts
Quote:
Originally Posted by Vman455 View Post
What happens when the wheels turn?
I'm imagining the ribs are roughly triangular, and when you turn the wheels, the clear the tabs on the edges. The one in the middle might have to go.
  Reply With Quote
Old 09-08-2018, 08:14 AM   #5 (permalink)
Master EcoModder
 
Join Date: Jun 2016
Location: KY
Posts: 1,346

IGL - '04 Saturn Ion
Team Saturn
90 day: 56.19 mpg (US)
Thanks: 63
Thanked 364 Times in 268 Posts
Quote:
Originally Posted by Ecky View Post
I'm imagining the ribs are roughly triangular, and when you turn the wheels, the clear the tabs on the edges. The one in the middle might have to go.
In the article in the link, the manufacturer specifies a rectangular cross section... is a good point though, with a very wide tire it wouldn’t work without rubbing... now the rear wheel wells would be good for such a device but we usually skirt those here on EM...
__________________
My current Ecotec project...


My last Ecotec project...
  Reply With Quote
Old 09-08-2018, 09:40 AM   #6 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2012
Location: Charlotte, NC
Posts: 134

TBD - '17 Toyota Corolla LE
90 day: 40.79 mpg (US)

Starship - '08 Toyota Prius
90 day: 41.57 mpg (US)
Thanks: 143
Thanked 110 Times in 47 Posts
Ruberized conveyor belt material pulled taunt. That's what I'm using for my side skirts underneath my car. Poke the belt thought a couple of places in the inner fender and make a metallic braket to attach on the back side. Job done. Tire rubs up against the converyor belt, no worries. Hardest part of this is figuring out how to get the inner fender out to work on it.
  Reply With Quote
Old 09-08-2018, 02:55 PM   #7 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,562
Thanks: 7,738
Thanked 8,554 Times in 7,041 Posts


Lower right corner — Vortex traps. Just applied to the fender well.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
  Reply With Quote
The Following 2 Users Say Thank You to freebeard For This Useful Post:
oldtamiyaphile (09-10-2018), woodstock74 (09-08-2018)
Old 09-20-2018, 12:37 PM   #8 (permalink)
Master EcoModder
 
Join Date: Mar 2008
Location: USA
Posts: 568
Thanks: 1
Thanked 73 Times in 58 Posts
Quote:
Originally Posted by freebeard View Post


Lower right corner — Vortex traps. Just applied to the fender well.
Seems to me, such vortex traps could be easily and inexpensively made with Coroplast, cut with a compass device to match the round curvature of the tire, then mounted to the inner fender liner.

This application appears to have some conceptual semblance to a ducted fan, where the duct necessarily has a very small gap between the spinning propeller blade tips, to prevent spillage of air from the positive pressure behind the blade, i.e., to act as a flow fence to prevent vortices and associated loss of efficiency. In other words, the spinning tire acts as a crude turbine, and the vortex trap flow fences act to contain the vortices, rather than have them escape outboard only to bugger the airflow past the wheel well opening.

I wonder how such vortex traps would compare with air curtains' efficiency?
  Reply With Quote
The Following User Says Thank You to Otto For This Useful Post:
freebeard (09-20-2018)
Old 09-30-2018, 11:17 AM   #9 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 4,158
Thanks: 120
Thanked 2,790 Times in 1,959 Posts
Those wheel well ribs as pointed out would probably be made of a flexible material like conveyor belt material.

Somewhere a study would have to be done on cost/maintenance/friction in turns/and perhaps retractability and operable vanes/fins. Possible tire rubber wear would also be a possible liability.

Overall I like the concept and see it as a sort of rear diffuser for wheel wells.

Aside topic from paper regarding:
SECTION 5.2.1
Wake Pumping Mode...........................

Absolutely fascinating as I think anyone that has rode a motorcycle has felt their open jacket whipping about, or driven in a car with windows rolled down and suffered cabin buffeting has experienced.

I wonder if Wake Pumping Mode is what causes some hovercraft to "Porpoise", that is to say suffer from bow to stern up and down bobbing or "heave" (longitudinal instability) not caused by surface wave action but caused by aerodynamic forces.
__________________
George
Architect, Artist and Designer of Objects

1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft

Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html
  Reply With Quote
Old 09-30-2018, 12:42 PM   #10 (permalink)
Corporate imperialist
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 11,175

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
Thanks: 269
Thanked 3,522 Times in 2,796 Posts
What if you have a regular small car and the wheels are relatively tiny compared to the wheel wells?

__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com