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


Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-19-2018, 07:42 PM   #741 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,093

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: 2,307
Thanked 2,028 Times in 1,381 Posts
Quote:
Originally Posted by gumby79 View Post
Finally got a video stiched together and up loded.
Air Flow / Tuft Testing my Aero Tonto



Edit: link fixed
I want to tell you that I looked at your album on your EM page too, and this is a cool looking wing from profile, too. It has a zoomorphic look--like bat or cat ears. Thanks for fixing the video link. The tufts look great. What is the reason for the "ears"? Redirecting flow toward the boat tail?

__________________
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
The Following User Says Thank You to California98Civic For This Useful Post:
NeilBlanchard (08-20-2018)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-19-2018, 09:24 PM   #742 (permalink)
Master EcoModder
 
gumby79's Avatar
 
Join Date: Dec 2014
Location: Butte, Montana
Posts: 719

little jona - '91 Dodge D 250 first gen cummins LE
Team Streamliner
90 day: 23.4 mpg (US)

Little Jona airo modded - '91 Dodge RAM 3/4 TON D 250 24 AUTO
Pickups
Team Cummins
90 day: 18.5 mpg (US)

The Salted Hound Jenny. - '87 Dodge Ram 50/D-50 5sp 4X4
90 day: 20.24 mpg (US)

Jona Allison aero - '91 Dodge Ram D-250 Le
90 day: 20.67 mpg (US)
Thanks: 208
Thanked 419 Times in 272 Posts
Quote:
What is the reason for the "ears"? Redirecting flow toward the boat tail?
It is part of the functional design of the standalone headache rack/ long load carrying support to prevent damage to cab from ladders and long pipe.
I made a mistake matching the silhouette of the back of a cab, wound up being too short on the corners and dead even in the center(load sitting on cab sheet metal). So I added the flat 1:24 wing (24x longer than thick =1/8"3)with 3/16" positive camber(nose up) center 0 off horizontal, 3/8" pos. camber at the tips. The triangular supports mid-span are also set to approximately 10 to 15 degrees out of air flow travel direction ( would cause counter-rotating vortexes off of each leg of the triangle
All wings that produce lift have down wash. So yes the patch(wing) is designed to use the down wash to catch and mitigate the turbulence caused by the cab to canopy gap ( second thing the wing patch was the cab angles forward resulting in my ideal half inch at the base of a headache rack and 3.5" at the top).


---
Quote:
freebeard
Quote:
It demonstrates what is happening in the wheel wells very nicely. At 0:03 and 0:51
Sorta. It would be better with the wheel rotating.
Yesterday 07:43 AM
agreed spin would be better . Best would be engine running at various speeds primarily Peak torque and Peak horsepower and a moving floor treadmill, while we're at it dreaming big put that treadmill on a turntable so we can account for crosswind interaction. wind is almost never straight on so the strate up wind tunnel testing only demonstrates about 2% of real world conditions primarily the Gorge between Bonneville Dam and The Dalles
__________________
1st gen cummins 91.5 dodge d250 ,HX35W/12/6 QSV
ehxsost manafulld wrap, Aero Tonto
best tank: distance 649gps mi 24.04 mpg 27.011usg
Best mpg : 31.32mpg 100mi 3.193 USG 5/2/20


Former
'83 GMC S-15 Jimmy 2door 2wd O/D auto 3.73R&P
'79 Chevy K20 4X4 350ci 400hp msd custom th400 /np205. 7.5-new 14mpg modded befor modding was a thing
87' Hyundai Excel
83 ranger w/87 2.9 L FI2wd auto 18mpg on the floor
04 Mitsubishi Gallant 2.4L auto 26mpg
06 Subaru Forrester XT(WRX PACKAGE) MT AWD Turbocharged 18 plying dirty best of 26mpg@70mph
95Chevy Blazer 4x4 auto 14-18mpg
04 Chevy Blazer 4x4 auto 16-22mpg


  Reply With Quote
The Following 2 Users Say Thank You to gumby79 For This Useful Post:
aerohead (08-30-2018), California98Civic (08-20-2018)
Old 08-22-2018, 05:00 PM   #743 (permalink)
Master EcoModder
 
redneck's Avatar
 
Join Date: Jun 2009
Location: SC Lowcountry
Posts: 1,398

Geo XL1 - '94 Geo Metro
Team Metro
Boat tails and more mods
90 day: 72.22 mpg (US)

Big, Bad & Flat - '01 Dodge Ram 3500 SLT
Team Cummins
90 day: 21.13 mpg (US)
Thanks: 184
Thanked 1,129 Times in 551 Posts
Quote:
Originally Posted by ratgreen View Post


Some interesting results. The front dam actually made its Cd worse
I won't post the newest Leroy video because it isn't a "smoke" related picture or video.

However, they did "smoke" a record...

7.824 seconds in the 1/4 mile at 176.57 mph.


All horsepower no aero.

Imagine what it could do with a properly designed body.


If you want to see the video just Google it.

WORLD'S FIRST Stick Shift GM In The SEVENS! Leroy's Most INSANE Pass!







>
  Reply With Quote
The Following User Says Thank You to redneck For This Useful Post:
aerohead (08-30-2018)
Old 10-08-2018, 02:57 AM   #744 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 18,052
Thanks: 4,946
Thanked 5,968 Times in 4,771 Posts
Just A Car Guy: streamliner... origin of the word



I thought this might be appropriate for this thread, but when you get to the bottom there is a Youtube video from this channel:

https://www.youtube.com/channel/EcoModderDOTcom

With 491 subscribers, one video posted a year until two years ago. Who's in charge?
__________________
.
Good sense, innocence, cripplin' mankind
Dead kings, many things I can't define
Occasions, persuasions clutter your mind
Incense and peppermints, the color of time

Who cares what games we choose?
Little to win, but nothin' to lose


"Incense And Peppermints"
_________________
  Reply With Quote
The Following User Says Thank You to freebeard For This Useful Post:
aerohead (10-10-2018)
Old 10-09-2018, 09:02 PM   #745 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 18,052
Thanks: 4,946
Thanked 5,968 Times in 4,771 Posts
Random but not smokey. I'm not sure where to put what I found:

Aerodynamic Car Shapes^@#





I don't recall seeing those before.
__________________
.
Good sense, innocence, cripplin' mankind
Dead kings, many things I can't define
Occasions, persuasions clutter your mind
Incense and peppermints, the color of time

Who cares what games we choose?
Little to win, but nothin' to lose


"Incense And Peppermints"
_________________
  Reply With Quote
The Following 2 Users Say Thank You to freebeard For This Useful Post:
aerohead (10-10-2018), COcyclist (10-10-2018)
Old 10-10-2018, 10:38 AM   #746 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 3,696
Thanks: 34
Thanked 2,429 Times in 1,705 Posts
Top image using a reverse image search says:

https://www.evolutionm.net/forums/mo...iffuser-4.html
Quote:
This is one of my favorite books on the subject, "Race Car Aerodynamics" by Josef Katz (http://www.bentleypublishers.com/aut...y-768-8.html):
Link is from 2009 and broken, but we now know the source.

NOTE: Image also found here with some other Aero-Images.

http://linkpat.info/aerodynamic-shapes-b593.html


Race Car Aerodynamics: Designing for Speed (Technical including tuning & modifying) by Joseph Katz (2006) Paperback
https://www.amazon.com/Race-Car-Aero.../dp/B00NPNUQX0
__________________
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

Last edited by kach22i; 10-10-2018 at 10:45 AM..
  Reply With Quote
The Following User Says Thank You to kach22i For This Useful Post:
aerohead (10-10-2018)
Old 10-10-2018, 12:05 PM   #747 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 18,052
Thanks: 4,946
Thanked 5,968 Times in 4,771 Posts
Any luck with the second one? VW-P3 appears equivalent to my Dasher while VW-P4 appears equivalent to the Rabbit/Golf.

I don't understand the two VW-P4 but only one VW-P3 profiles.

It looks like if the Dasher's profile was pushed to 74 it would be a slippery as the Golf/Rabbit. Does it make sense to apply the lower left scenario to the upper profile?
__________________
.
Good sense, innocence, cripplin' mankind
Dead kings, many things I can't define
Occasions, persuasions clutter your mind
Incense and peppermints, the color of time

Who cares what games we choose?
Little to win, but nothin' to lose


"Incense And Peppermints"
_________________
  Reply With Quote
Old 10-10-2018, 12:56 PM   #748 (permalink)
Aero Wannabe
 
COcyclist's Avatar
 
Join Date: Dec 2007
Location: NW Colo
Posts: 670

TDi - '04 VW Golf
TEAM VW AUDI Group
90 day: 53.89 mpg (US)
Thanks: 560
Thanked 178 Times in 139 Posts
Quote:
Originally Posted by freebeard View Post
Any luck with the second one? VW-P3 appears equivalent to my Dasher while VW-P4 appears equivalent to the Rabbit/Golf.

I don't understand the two VW-P4 but only one VW-P3 profiles.

It looks like if the Dasher's profile was pushed to 74 it would be a slippery as the Golf/Rabbit. Does it make sense to apply the lower left scenario to the upper profile?
Perhaps these were all wind tunnel mock-ups of the mkI Golf/Rabbit. The 34 degree in the lower left looks closer to the mkIV Golf (my car) and if I read the graph correctly the triangles show lower Cd. Somewhere on here I remember seeing the back should be chopped at vertical for lowest drag.
__________________
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
The Following 2 Users Say Thank You to COcyclist For This Useful Post:
aerohead (10-13-2018), freebeard (10-10-2018)
Old 10-10-2018, 03:13 PM   #749 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 18,052
Thanks: 4,946
Thanked 5,968 Times in 4,771 Posts


When I put a protractor on this I ascertain ~25 from horizontal, AKA 65. The diagram seems to me to be ambiguous about whether the angle is measured from the top or bottom and from the horizontal or vertical.

I think what I need for a Kammback is a short top with tapering sail panels.
__________________
.
Good sense, innocence, cripplin' mankind
Dead kings, many things I can't define
Occasions, persuasions clutter your mind
Incense and peppermints, the color of time

Who cares what games we choose?
Little to win, but nothin' to lose


"Incense And Peppermints"
_________________
  Reply With Quote
Old 10-10-2018, 03:17 PM   #750 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 3,696
Thanks: 34
Thanked 2,429 Times in 1,705 Posts
Quote:
Originally Posted by freebeard View Post
Any luck with the second one? VW-P3 appears equivalent to my Dasher while VW-P4 appears equivalent to the Rabbit/Golf.
I looked for about seven minutes and did not find it's true source.

However I found this nifty PDF from India (a download).

https://www.google.com/url?sa=i&rct=...39281492253127

And a review of the preciously mentioned book including a few pages of the inside.


2013
Racecar Aerodynamics: Designing for Speed by Joseph Katz Book Review
The Avid Engineer: Racecar Aerodynamics: Designing for Speed by Joseph Katz Book Review
Quote:
Conclusion:
I really rate this book highly and I often find myself referring to it over some of my more analytical books like Understanding Aerodynamics by Doug McLean. The way the author always explains concepts in such a clear and concise manner is especially welcome, which is helpful if like myself you are a keen F1 fan and often find the televised explanations lacking and need a quick reference just to suss out possible benefits of recent changes. In this regard the book would make an excellent present for any one interested in forms of racing.


EDIT: I just liked this picture...................

http://forums.pelicanparts.com/off-t...taken-631.html

I wonder what the little guy's Cd was.

__________________
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

Last edited by kach22i; 10-14-2018 at 12:58 PM..
  Reply With Quote
The Following User Says Thank You to kach22i For This Useful Post:
freebeard (10-10-2018)
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com