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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-11-2011, 06:55 PM   #1 (permalink)
Master EcoModder
 
bondo's Avatar
 
Join Date: Jan 2008
Location: Arkansas
Posts: 279
Thanks: 90
Thanked 240 Times in 90 Posts
Flow Visualization on new tailcone.

Got out the yarn and duct tape yesterday and hit the road. We have been seeing 23 to 25 mpg in over the road testing. The air flows nice over the top. The sides, a little to be desired but did not want to eclipse the tailights. The turbulence of the wake seems to have been reduced as shown by the laziness of the tufts stuck on the very back.

This new device is held in place by the rotary latches in the lowered tailgate. To remove it, just reach under and pull the tailgate handle which releases the rotary latches.

Thanks,

Bondo


  Reply With Quote
The Following 8 Users Say Thank You to bondo For This Useful Post:
aerohead (07-12-2011), BamZipPow (07-12-2011), Cd (07-11-2011), jime57 (07-13-2011), KamperBob (07-12-2011), Piwoslaw (07-12-2011), t vago (07-11-2011), wyatt (07-13-2011)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-11-2011, 07:15 PM   #2 (permalink)
MPGuino Supporter
 
t vago's Avatar
 
Join Date: Oct 2010
Location: Hungary
Posts: 1,807

iNXS - '10 Opel Zafira 111 Anniversary

Suzi - '02 Suzuki Swift GL
Thanks: 828
Thanked 708 Times in 456 Posts
Could you use some Lexan on the sides?

Awesome testing!
  Reply With Quote
Old 07-11-2011, 07:24 PM   #3 (permalink)
DieselMiser
 
ConnClark's Avatar
 
Join Date: Jun 2008
Location: Richland,WA
Posts: 985

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
Thanks: 46
Thanked 231 Times in 160 Posts
You might want to taper in the sides and the bottom to keep it from obscuring the view of the lights and license plate from an angle.
__________________
  Reply With Quote
Old 07-12-2011, 08:57 AM   #4 (permalink)
Master EcoModder
 
bondo's Avatar
 
Join Date: Jan 2008
Location: Arkansas
Posts: 279
Thanks: 90
Thanked 240 Times in 90 Posts
Good idea t vago.

Quote:
Originally Posted by t vago View Post
Could you use some Lexan on the sides?

Awesome testing!
The trick is going to be how to fasten it to the truck. Would get rid of the low pressure area just inboard of the tail lights.

Bondo
  Reply With Quote
Old 07-12-2011, 09:14 AM   #5 (permalink)
Master EcoModder
 
bondo's Avatar
 
Join Date: Jan 2008
Location: Arkansas
Posts: 279
Thanks: 90
Thanked 240 Times in 90 Posts
Quote:
Originally Posted by ConnClark View Post
You might want to taper in the sides and the bottom to keep it from obscuring the view of the lights and license plate from an angle.
For view field of the tailights the sides should be angled in more. The problem is you would get less effective aero. The angle chosen was determined off a CFD simulation. Any more angle inboard would have rsulted in even less reattachment of air flow to the surface, which with the step inboard from the tail lights isn't much already.

I was tailed by an Arkansas State Policeman on the first leg of the run. He didn't pull me over so we passed the first test. You can see him at about 2:58time in the video parked to the far left in the opposite bound lanes.

The open tailgate defines the angle at the bottom so can't do much there.

Bondo
  Reply With Quote
Old 07-12-2011, 01:12 PM   #6 (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
Useful video, the commentary was good too.
__________________
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
The Following User Says Thank You to kach22i For This Useful Post:
bondo (07-13-2011)
Old 07-12-2011, 02:55 PM   #7 (permalink)
T-100 Road Warrior
 
BamZipPow's Avatar
 
Join Date: Apr 2008
Location: The Woodlands, TX
Posts: 1,920

BZP T-100 (2010) - '98 Toyota T-100 ext cab - 3.4L/auto SR5
Last 3: 24 mpg (US)

BZP T-100 (2011) - '98 Toyota T-100 ext cab - 3.4L/auto SR5
Last 3: 23.66 mpg (US)

BZP T-100 (2009) - '98 Toyota T-100 ext cab - 3.4L/auto SR5
Last 3: 19.01 mpg (US)

BZP T-100 (2012) - '98 Toyota T-100 ext cab - 3.4L/auto SR5
Last 3: 25.45 mpg (US)

BZP T-100 (2013) - '98 Toyota T-100 SR5
Last 3: 25.79 mpg (US)

BZP T-100 (2014) - '98 Toyota T-100 SR5
Last 3: 23.18 mpg (US)

BZP T-100 (2015) - '98 Toyota T-100 SR5
Last 3: 23.85 mpg (US)

BZP T-100 (2016) - '98 Toyota T-100 SR5
Last 3: 17.62 mpg (US)

BZP T-100 (2017) - '98 Toyota T-100 SR5
90 day: 20.78 mpg (US)

BZP T-100 (2018) - '98 Toyota T-100 SR5
90 day: 20.19 mpg (US)

BZP T-100 (2019) - '98 Toyota T-100 SR5

BZP T-100 (2020) - '98 Toyota T-100 SR5

2012 Scion iQ - '12 Scion iQ Base
Thanks: 3,479
Thanked 1,395 Times in 968 Posts
Send a message via ICQ to BamZipPow
Since you have the tailgate down as the bottom layer of the tail cone...you can put in a rear window on the tail cone fer better rear vision!

Looks good. How do you store it?

I guess you could test some clear covers that extend from the tail lights to the end of the tail cone.
__________________
Dark Aero-The world's first aerodynamic single wheel boat tail!

  Reply With Quote
Old 07-12-2011, 09:42 PM   #8 (permalink)
Aero Wannabe
 
COcyclist's Avatar
 
Join Date: Dec 2007
Location: NW Colo
Posts: 738

TDi - '04 VW Golf
TEAM VW AUDI Group
90 day: 53.2 mpg (US)
Thanks: 705
Thanked 218 Times in 169 Posts
Nice work Bondo! Watching the tufts I really want to see it tested with rear wheel skirts on your rig. It looks to me like the tufts just behind the wheelwell are really disturbed. I wonder if the air would reattach to your extension if it were smooth before it left the taillights???
__________________
60 mpg hwy highest, 50+mpg lifetime
TDi=fast frugal fun
https://ecomodder.com/forum/showthre...tml#post621801


Quote:
Originally Posted by freebeard View Post
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
  Reply With Quote
Old 07-13-2011, 10:50 AM   #9 (permalink)
Master EcoModder
 
bondo's Avatar
 
Join Date: Jan 2008
Location: Arkansas
Posts: 279
Thanks: 90
Thanked 240 Times in 90 Posts
Quote:
Originally Posted by BamZipPow View Post
Since you have the tailgate down as the bottom layer of the tail cone...you can put in a rear window on the tail cone fer better rear vision!

Looks good. How do you store it?

I guess you could test some clear covers that extend from the tail lights to the end of the tail cone.
An Aerolid does need help on rearward visibility, that would be a great way to gain some.

The tailcone fits nicely inside the truck bed when not in use. basjoos had this idea figured out over two years ago. He has forgotten more than I will ever know about aerodynamics. His post is the fifth one at the link below.

While at this link, check out round.boaters up to date fuel log. He is getting much better than a 4% increase in fuel efficiency.

http://ecomodder.com/forum/showthrea...olid-8444.html


Bondo
  Reply With Quote
The Following 2 Users Say Thank You to bondo For This Useful Post:
aerohead (07-13-2011), BamZipPow (07-13-2011)
Old 07-13-2011, 10:53 AM   #10 (permalink)
Master EcoModder
 
bondo's Avatar
 
Join Date: Jan 2008
Location: Arkansas
Posts: 279
Thanks: 90
Thanked 240 Times in 90 Posts
Quote:
Originally Posted by COcyclist View Post
Nice work Bondo! Watching the tufts I really want to see it tested with rear wheel skirts on your rig. It looks to me like the tufts just behind the wheelwell are really disturbed. I wonder if the air would reattach to your extension if it were smooth before it left the taillights???
You are right! That is the next step. The next flow visualization we do there will be wheel skirts over the rear wheel openings.



Thanks,

Bondo

  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