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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-24-2008, 10:27 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: Jan 2008
Location: Sydney, Australia
Posts: 76

Piaggio Fly 150 - '10 Piaggio Fly 150
90 day: 64.8 mpg (US)
Thanks: 1
Thanked 3 Times in 3 Posts
MIT theory can finally predict 3D flow seperation.

Check out this article, up until now mathematically predicting flow separation has been a complete mystery. I'm not smart enough to know the practical impact of this, but I assume it means the design of low drag shapes (and vehicles) will become a lot easier and computation fluid dynamics will get a lot more accurate.

__________________
Check out my Green Cars Blog and the DIY electric car Wiki. Enjoy!
  Reply With Quote
The Following User Says Thank You to mattW For This Useful Post:
Cd (02-26-2010)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-24-2008, 11:02 PM   #2 (permalink)
Pokémoderator
 
cfg83's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 5,864

1999 Saturn SW2 - '99 Saturn SW2 Wagon
Team Saturn
90 day: 40.49 mpg (US)
Thanks: 439
Thanked 532 Times in 358 Posts
mattW -

Great find! I don't know what it means, but solving a 100 year old problem has to count for something.

CarloSW2
__________________

What's your EPA MPG? Go Here and find out!
American Solar Energy Society
  Reply With Quote
Old 09-25-2008, 08:02 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
3-d

It's a great thing.Cheap computer energy can do the work once relegated to only really good windtunnels(which can use enough electricity to dim the lights of an entire city!) The windtunnel can do the final "visual" verification and dry laundry! Way cool!
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 09-27-2008, 12:45 AM   #4 (permalink)
EcoModding Apprentice
 
Join Date: Mar 2008
Location: Des Moines, IA
Posts: 155

Nerdcycle - '81 Honda CM400E
Motorcycle
90 day: 61.16 mpg (US)

Trouble - '06 Kawasaki Ninja
90 day: 74.69 mpg (US)

Edna - '13 Nissan LEAF SV
Last 3: 133.3 mpg (US)

Tank - '20 Ford Expedition Limited
Last 3: 17.4 mpg (US)
Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by aerohead View Post
It's a great thing.Cheap computer energy can do the work once relegated to only really good windtunnels(which can use enough electricity to dim the lights of an entire city!) The windtunnel can do the final "visual" verification and dry laundry! Way cool!
Plus, all of us here obviously have computers, which can't be said for wind tunnels.

Random thought: I think the picture looks like an eyeball, out of the socket of course.
__________________

  Reply With Quote
Old 09-27-2008, 05:01 PM   #5 (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
eyeballs

Quote:
Originally Posted by extragoode View Post
Plus, all of us here obviously have computers, which can't be said for wind tunnels.

Random thought: I think the picture looks like an eyeball, out of the socket of course.
Looks like the eyeballs on that MIT interactive cuddly robot with fur.It's a MIT thing!
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 02-24-2010, 06:02 PM   #6 (permalink)
Recreation Engineer
 
KamperBob's Avatar
 
Join Date: Dec 2009
Location: Somewhere USA
Posts: 525

Black Stallion - '02 Toyota Tundra 4WD xCab

Half Pint - '06 Yamaha XT225
Thanks: 333
Thanked 138 Times in 103 Posts
So it's been a year and a half since this MIT "discovery" was made. The article itself sure is light on technical content. Anyone know more? How exactly are we exploiting this knowledge?

Cheers
KB
  Reply With Quote
Old 02-24-2010, 06:21 PM   #7 (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
exploiting

Quote:
Originally Posted by KamperBob View Post
So it's been a year and a half since this MIT "discovery" was made. The article itself sure is light on technical content. Anyone know more? How exactly are we exploiting this knowledge?

Cheers
KB
I suspect that this technology will remain in the domain of the automakers tech centers for some time before we'll gain access to it.Hope I'm wrong.
The other part of the equation,is how easy will it be to input the spherical coordinates when setting up the paneling of the body for the Navier-Stokes numbers-crunching to do its thing.
  Reply With Quote
Old 02-24-2010, 08:26 PM   #8 (permalink)
Left Lane Ecodriver
 
RobertSmalls's Avatar
 
Join Date: Aug 2008
Location: Buffalo, NY, USA
Posts: 2,257

Prius C - '12 Toyota Prius C
Thanks: 79
Thanked 287 Times in 200 Posts
Well, the article mentions the equations were published in a journal. So once they are experimentally validated, expect them to show up behind the scenes in CFD toolboxes, some of which are open source and free to download.
  Reply With Quote
The Following User Says Thank You to RobertSmalls For This Useful Post:
aerohead (02-27-2010)
Old 02-25-2010, 08:02 AM   #9 (permalink)
Master EcoModder
 
Join Date: Oct 2008
Location: Mid-Atlantic
Posts: 491

OurInsight - '06 Honda Insight
Thanks: 170
Thanked 69 Times in 44 Posts
Very interesting article! I note a couple of things:
1. A car has to deal with ground planes and there is no mention of them in this brief article.
2. Most interesting to me was the red and green areas of the graphic. The article mentions that the red lines represent "classic" computation of separation. The green lines represent the "new" theory. From the graphic it sure looks like unseparated flow exists much longer than we had thought SO LONG AS THE SHAPE TRANSITION IS GRADUAL. Don't know that "final" angle on the sphere, but it could be 30 degrees or so.
  Reply With Quote
Old 02-27-2010, 02:14 PM   #10 (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
ground plane

Quote:
Originally Posted by jimepting View Post
Very interesting article! I note a couple of things:
1. A car has to deal with ground planes and there is no mention of them in this brief article.
2. Most interesting to me was the red and green areas of the graphic. The article mentions that the red lines represent "classic" computation of separation. The green lines represent the "new" theory. From the graphic it sure looks like unseparated flow exists much longer than we had thought SO LONG AS THE SHAPE TRANSITION IS GRADUAL. Don't know that "final" angle on the sphere, but it could be 30 degrees or so.
I don't know about the angle,but I believe Hucho mentioned,that with CFD,they all use the 'mirror-image'/ 'ground-reflection' technique to allow for the ground effect.

  Reply With Quote
Reply  Post New Thread


Tags
flow separation, mathematics, mit



Similar Threads
Thread Thread Starter Forum Replies Last Post
The Mechanism Behind Flow Separation LostCause Aerodynamics 46 07-15-2010 08:38 AM



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