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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-02-2011, 11:35 PM   #1 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2011
Location: Orange Country, CA
Posts: 102

Fiesta - '12 Ford Fiesta SE
90 day: 31.45 mpg (US)
Thanks: 36
Thanked 3 Times in 3 Posts
cap on car

My car is a convertible, so some mods are a bit harder, or altogether impossible, to do than on a normal car. But I had an idea, if I were to use a screen that goes from the top of the rear windows to the trunk to make a sort of cap, does anyone think it would be very effective? I remember reading in another post using screen as a grill block but someone said it would only work if the the screen was at an angle. I'm making a picture of my idea now.



In the morning sometimes there's leaves on my roof and as I start to drive they get stuck right on my rear window, the vortex there is clearly visible and must create quite a bit of drag, and it would be awesome to reduce it!

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-02-2011, 11:40 PM   #2 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2011
Location: Orange Country, CA
Posts: 102

Fiesta - '12 Ford Fiesta SE
90 day: 31.45 mpg (US)
Thanks: 36
Thanked 3 Times in 3 Posts
Something like this, not very good with Internet drawing tools haha
there would be supports and stuff of course
  Reply With Quote
Old 06-03-2011, 04:56 PM   #3 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,306
Thanks: 24,436
Thanked 7,384 Times in 4,782 Posts
screen

Quote:
Originally Posted by capnbass91 View Post
My car is a convertible, so some mods are a bit harder, or altogether impossible, to do than on a normal car. But I had an idea, if I were to use a screen that goes from the top of the rear windows to the trunk to make a sort of cap, does anyone think it would be very effective? I remember reading in another post using screen as a grill block but someone said it would only work if the the screen was at an angle. I'm making a picture of my idea now.



In the morning sometimes there's leaves on my roof and as I start to drive they get stuck right on my rear window, the vortex there is clearly visible and must create quite a bit of drag, and it would be awesome to reduce it!
My library is certainly incomplete and if there had ever been a dedicated research project to investigate such a thing,it could have easily slipped my net.So,scientifically,I can't give a hard answer.
Here are some things that enter my mind:
* air cannot support loads,so a porous surface as the screen may be 'invisible' to the air and will still be affected by any variations in flow velocity or pressure variations 'contained within the screened area.
* if separation is imminent,the presence of the screen may offer no 'surface' for which the flow to re-attach.
* if the surface had more substance( like the laser-drilled panels on some recent experimental research aircraft),and if suction were applied inside it,you'd have a chance for remarkable drag reduction.The snag so far has been the amount of power to drive the air mover.
* for practical home streamlining projects we may be forced to use 'solid' surfaces with which to enhance airflow.
* A doped fabric covering was used on the US' first amateur streamlined dry lakes land speed record car to good effect.
  Reply With Quote
Old 06-03-2011, 06:07 PM   #4 (permalink)
EcoModding Lurker
 
Join Date: Aug 2010
Location: Netherlands
Posts: 43
Thanks: 0
Thanked 9 Times in 7 Posts
Mercedes made a front windshield "wing"/deflector to relocate the flow above the drivers and thus the turbulant section.
Still aero but with the top open!
It's called aircap.
It has a cd of 0.28 !!



Mercedes-Benz AirCap calms convertible winds - Automobile Magazine Blog

Last edited by beer; 06-03-2011 at 06:14 PM..
  Reply With Quote
Old 06-03-2011, 06:20 PM   #5 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2011
Location: Houston
Posts: 228
Thanks: 0
Thanked 23 Times in 17 Posts
0.28 my foot.

OP, not sure what you are describing.
  Reply With Quote
Old 06-03-2011, 06:36 PM   #6 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,306
Thanks: 24,436
Thanked 7,384 Times in 4,782 Posts
roof up?

Quote:
Originally Posted by beer View Post
Mercedes made a front windshield "wing"/deflector to relocate the flow above the drivers and thus the turbulant section.
Still aero but with the top open!
It's called aircap.
It has a cd of 0.28 !!



Mercedes-Benz AirCap calms convertible winds - Automobile Magazine Blog
beer,do you think the Cd as recorded with the top up on the M-B?
  Reply With Quote
Old 06-03-2011, 07:51 PM   #7 (permalink)
EcoModding Lurker
 
Join Date: Aug 2010
Location: Netherlands
Posts: 43
Thanks: 0
Thanked 9 Times in 7 Posts
Top on! Duh
But still this the aerocap reduces the wake, compared with other cabrios.
But ofcours it main use is the keep the passengers out of the wind
  Reply With Quote
Old 06-03-2011, 08:01 PM   #8 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,306
Thanks: 24,436
Thanked 7,384 Times in 4,782 Posts
passengers

Quote:
Originally Posted by beer View Post
Top on! Duh
But still this the aerocap reduces the wake, compared with other cabrios.
But ofcours it main use is the keep the passengers out of the wind
I think that's it.I drove the Autobahn in 1997.Doing 124 mph in a rented Mitsubishi Galant was passed by big 6-series Bimmers and Benz coupes and sedans.
Can't imagine what an open car would be like at those speeds.I don't even like 80 mph on a motorcycle.
  Reply With Quote
Old 06-03-2011, 09:08 PM   #9 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
I don't think it's worth it. What you're describing is basically just what the soft top is.
  Reply With Quote
Old 06-03-2011, 10:43 PM   #10 (permalink)
Aero Deshi
 
ChazInMT's Avatar
 
Join Date: Jan 2010
Location: Vero Beach, FL
Posts: 1,065

MagMetalCivic - '04 Honda Civic Sedan EX
Last 3: 34.25 mpg (US)
Thanks: 430
Thanked 669 Times in 358 Posts
Looks to me like you need to use Tiny Pic for your photo hosting needs.

You wanna do something like this eh?


  Reply With Quote
Reply  Post New Thread






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