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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-07-2013, 02:56 AM   #1 (permalink)
Lots of Questions
 
Join Date: Jan 2013
Location: San Jose
Posts: 665

Motor-Rolla - '01 Toyota Corolla LE
Team Toyota
90 day: 28.3 mpg (US)

Gaia - '99 Toyota 4Runner SR5 Highlander
90 day: 19.78 mpg (US)

Gaia - Round 2 - '99 Toyota 4runner SR5 Highlander
90 day: 17.23 mpg (US)
Thanks: 343
Thanked 101 Times in 79 Posts
Making a "Kammback" with the Sunroof and Rear Window

Lester has a sunroof and rear window. I was wondering what would happen to the aerodynamics of the truck if I were to open both of them. Does anybody have any idea what that would do or can anybody do one of those airflow diagrams to see how it would work?

Thanks!

__________________
Don't forget to like our Facebook page!




Best EM Quotes:
Quote:
Originally Posted by aerohead View Post
It has been said, that if you peel the duct tape back on Earth's equator, you'll find that the two hemispheres are held together with J B Weld.
Quote:
Originally Posted by Dan9 View Post
subscribed with a soda.
Quote:
Originally Posted by aerohead View Post
If you're burning,and someone throws gasoline on you,there will be a localized cooling effect, but you're still on fire.
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-07-2013, 08:14 AM   #2 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts


I think it would hurt the aerodynamics, especially with the sunroof open. Not sure what to think with just a rear window open. Assuming it is the kind that retracts into the door, I guess it starts to look a little like a box cavity back there, but box cavities have to be carefully tuned and their benefit is very small and highly interactive with other aero features, apparently.
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.



  Reply With Quote
Old 09-07-2013, 10:16 AM   #3 (permalink)
EcoModding Apprentice
 
Saskwatchian's Avatar
 
Join Date: Apr 2012
Location: Saskatchewan
Posts: 114

Eric's Explorer - '01 Ford Explorer Sport 4x4
90 day: 19.05 mpg (US)

E's V - '07 Nissan Versa SL
90 day: 33.11 mpg (US)
Thanks: 12
Thanked 25 Times in 18 Posts
Don't open the back window while driving unless you also have side windows open. You will be sucking your exhaust fumes into the vehicle.

If you want to try it do so on a gravel road, it will be obvious if you are sucking the wake into the cabin by the dust levels well before you get any CO poisoning.

I miss my 4Runner.
__________________
  Reply With Quote
The Following 2 Users Say Thank You to Saskwatchian For This Useful Post:
Cd (09-07-2013), jeff88 (09-07-2013)
Old 09-07-2013, 02:21 PM   #4 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 15,861
Thanks: 23,922
Thanked 7,207 Times in 4,640 Posts
open

I'll vote 'don't also.
The lowest pressure outside the vehicle is near the windshield.If you open the sunroof and rear glass,the low pressure above the roof will telegraph through the cabin,bringing air and exhaust fumes forward towards that low pressure as it attempts to equalize the static pressure between the two areas.
It not only ruins the airflow,but it poisons you to boot!
__________________
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:
Cd (09-07-2013), jeff88 (09-07-2013)
Old 09-07-2013, 03:16 PM   #5 (permalink)
Cd
Ultimate Fail
 
Cd's Avatar
 
Join Date: Feb 2008
Location: Austin,Texas
Posts: 3,585
Thanks: 2,872
Thanked 1,121 Times in 679 Posts
STOCK :
SUNROOF OPEN / BACK WINDOW OPEN :
SIDE WINDOWS OPEN / BACK WINDOW OPEN :
  Reply With Quote
The Following 3 Users Say Thank You to Cd For This Useful Post:
aerohead (09-07-2013), California98Civic (09-07-2013), jeff88 (09-07-2013)
Old 09-07-2013, 03:21 PM   #6 (permalink)
Cd
Ultimate Fail
 
Cd's Avatar
 
Join Date: Feb 2008
Location: Austin,Texas
Posts: 3,585
Thanks: 2,872
Thanked 1,121 Times in 679 Posts
I had pondered the same thing before on this forum. Thanks for the idea to test it in CFD.

Last edited by Cd; 09-07-2013 at 03:44 PM..
  Reply With Quote
The Following 2 Users Say Thank You to Cd For This Useful Post:
aerohead (09-07-2013), California98Civic (09-07-2013)
Old 09-07-2013, 03:30 PM   #7 (permalink)
Cd
Ultimate Fail
 
Cd's Avatar
 
Join Date: Feb 2008
Location: Austin,Texas
Posts: 3,585
Thanks: 2,872
Thanked 1,121 Times in 679 Posts
I'll test the coefficient of drag later to see how bad it gets with the windows open.
  Reply With Quote
The Following 2 Users Say Thank You to Cd For This Useful Post:
aerohead (09-07-2013), jeff88 (09-07-2013)
Old 09-07-2013, 03:41 PM   #8 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
Quote:
Originally Posted by Cd View Post
In all instances, the flow at the rear was sucked inward into the cabin. ( Appeared to at least. I can continue to test this )

I had pondered the same thing before on this forum. Thanks for the idea to test it in CFD.
This will sound uninformed, but why does the graphic seem to show slower air flow at the front of the vehicle when the windows are opened downstream? Is it because the open windows slow the ari around the greenhouse which in turn makes the flow at the front of the car slower?
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.



  Reply With Quote
Old 09-07-2013, 03:46 PM   #9 (permalink)
Cd
Ultimate Fail
 
Cd's Avatar
 
Join Date: Feb 2008
Location: Austin,Texas
Posts: 3,585
Thanks: 2,872
Thanked 1,121 Times in 679 Posts
Actually the flow appears to be moving out of the cabin. Here is a video :

http://www.flickr.com/photos/60376566@N00/9693089745/

I'm multitasking here and getting ahead of myself.

Last edited by Cd; 09-07-2013 at 10:06 PM..
  Reply With Quote
Old 09-07-2013, 03:50 PM   #10 (permalink)
Cd
Ultimate Fail
 
Cd's Avatar
 
Join Date: Feb 2008
Location: Austin,Texas
Posts: 3,585
Thanks: 2,872
Thanked 1,121 Times in 679 Posts
Quote:
Originally Posted by California98Civic View Post
This will sound uninformed, but why does the graphic seem to show slower air flow at the front of the vehicle when the windows are opened downstream? Is it because the open windows slow the ari around the greenhouse which in turn makes the flow at the front of the car slower?
This has me puzzled too.
I will test this later as well. I think it's the fact that my computer is bogged down from having too many things going and it is causing everything to act screwwy.

  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