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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-14-2015, 01:06 PM   #1 (permalink)
CFECO
 
CFECO's Avatar
 
Join Date: May 2008
Location: Vail, AZ.
Posts: 552

X-Car - '11 Homemade 2+2

Velbly1 - '17 Toyota Camery XSE
90 day: 29 mpg (US)

Velbly2 - '13 Toyota Tundra
90 day: 18.03 mpg (US)
Thanks: 174
Thanked 60 Times in 56 Posts
Using Power to improve Aerodynamics

This has probably been discussed before, but I could not find it, sorry if I missed it. Has anyone ever done any studies on what would happen if you took a blower, and sucked air out from under a vehicle, or from the high pressure area at the front, and blew it out into the wake area at the rear, basically "Filling The Vacuum" ?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-14-2015, 02:03 PM   #2 (permalink)
Rat Racer
 
Fat Charlie's Avatar
 
Join Date: May 2011
Location: Route 16
Posts: 3,299

Al the Third, year four - '13 Honda Fit Base
Team Honda
90 day: 42.9 mpg (US)
Thanks: 1,251
Thanked 1,354 Times in 874 Posts
Heh. Back in the 80s Car & Driver did a road test on a riding mower. They described the downforce package (underbody fan) in great detail, concluding that the air collecting bag was a bad idea because when operated offroad, it quickly became filled with crushed vegetation. That deficiency, and the rig's low top speed made themagazine question the need for a downforce generator like that.
__________________

Quote:
Originally Posted by sheepdog44 View Post
Transmission type Efficiency
Manual neutral engine off.100% @MPG <----- Fun Fact.
Manual 1:1 gear ratio .......98%
CVT belt ............................88%
Automatic .........................86%

  Reply With Quote
The Following User Says Thank You to Fat Charlie For This Useful Post:
CFECO (12-14-2015)
Old 12-14-2015, 02:28 PM   #3 (permalink)
CFECO
 
CFECO's Avatar
 
Join Date: May 2008
Location: Vail, AZ.
Posts: 552

X-Car - '11 Homemade 2+2

Velbly1 - '17 Toyota Camery XSE
90 day: 29 mpg (US)

Velbly2 - '13 Toyota Tundra
90 day: 18.03 mpg (US)
Thanks: 174
Thanked 60 Times in 56 Posts
My thought was not for downforce, but Drag reduction. Pull air from where we don't want it, high pressure areas, and vent it into the low pressure, wake area at the rear.
  Reply With Quote
Old 12-14-2015, 03:03 PM   #4 (permalink)
Rat Racer
 
Fat Charlie's Avatar
 
Join Date: May 2011
Location: Route 16
Posts: 3,299

Al the Third, year four - '13 Honda Fit Base
Team Honda
90 day: 42.9 mpg (US)
Thanks: 1,251
Thanked 1,354 Times in 874 Posts
You're trying to do something that occurs naturally, only better, and by using power... in an effort to reduce power usage.

If it were an effort to increase downforce or top speed, then by all means- that's using energy to create a desired effect. But if the desired effect is less energy loss, I think this is the wrong way to go.
__________________

Quote:
Originally Posted by sheepdog44 View Post
Transmission type Efficiency
Manual neutral engine off.100% @MPG <----- Fun Fact.
Manual 1:1 gear ratio .......98%
CVT belt ............................88%
Automatic .........................86%

  Reply With Quote
Old 12-14-2015, 03:17 PM   #5 (permalink)
EcoModding Lurker
 
Join Date: Apr 2012
Location: Mexico
Posts: 56

puntazo - '08 Fiat Grande Punto Sport T-Jet
Sports Cars
90 day: 32.94 mpg (US)

Pachanga ST - '14 Ford Fiesta ST ST3
Sports Cars
90 day: 28.59 mpg (US)
Thanks: 18
Thanked 6 Times in 6 Posts
Many years ago, like at late 70's if I'm not mistaken, some racing teams wanted to exploit just that. The first successful one was the Chaparral 2J, which had a 2-stroke engine from a snowmobile, I think, and connected to 2 big fans from a military tank and then they sealed the sides with skirts. It wasn't very successful because of reliability issues, but it was competitive when it was running.

Some years later, that concept was taken into F1, where the Brabham team put an enormous fan behind the car (The Brabham BT46B or "fan car"), which they said it was to cool the engine, but it was ducted in a way that half of it cooled the engine and the other half sucked the car. The fan was connected to the engine, so the higher the revs, the more the suction. The advantage was so huge that it was banned (that and because the other teams complained, so they withdraw and the next year the rules were changed to ban moving aerodynamic parts). It only ran in just one grand prix, which it won by a very big margin.

For ecomodding purposes, it may work, but as in the Chaparral, I don't think it's going to be easy, or cheap, or reliable and might be too heavy.

Last edited by Smokeduv; 12-14-2015 at 03:55 PM..
  Reply With Quote
Old 12-14-2015, 03:17 PM   #6 (permalink)
CFECO
 
CFECO's Avatar
 
Join Date: May 2008
Location: Vail, AZ.
Posts: 552

X-Car - '11 Homemade 2+2

Velbly1 - '17 Toyota Camery XSE
90 day: 29 mpg (US)

Velbly2 - '13 Toyota Tundra
90 day: 18.03 mpg (US)
Thanks: 174
Thanked 60 Times in 56 Posts
It would be a trade-off for sure, but would it be better or worse overall, that's the question. We know at higher speeds, Aero Drag is the main fuel user, and since the engines are not being used in their most efficient operating range most of the time, WOT under load, adding load to help aero "might" be good.
  Reply With Quote
Old 12-14-2015, 05:33 PM   #7 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,125
Thanks: 15,298
Thanked 5,389 Times in 3,174 Posts
trade-off

It's been considered since Prandtl's blown/suctioned wing research of the 1920s.
Georgia Tech continues research on it after decades of work.
So far,more energy is expended in moving the necessary volumes of air,than is saved with the modification.Also,the equipment can breakdown,something a streamlined shape cannot suffer.
The Ferrari 599XX race car has an intermittantly-used,porous, suctioned diffuser,enabled by two-trunk-mounted electric blowers which suck air from under and blow it cyclically through the taillights to detach the wake.
Together,all the 599XX mods drop the car to Cd 0.285,compared to Cd 0.336 for the base 599GTB.
Cd 0.285 is a long way from VW's passive,Cd 0.14 'flow body' of 1981.

__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
The Following 2 Users Say Thank You to aerohead For This Useful Post:
BamZipPow (12-14-2015), NickelB NL (01-31-2016)
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com