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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-31-2013, 09:17 PM   #1 (permalink)
Captain Planet
 
Join Date: Jul 2012
Location: Louisiana
Posts: 50

Smokey - '00 Honda Civic DX
Team Honda
90 day: 38.53 mpg (US)

Jade - '02 Acura RSX Type S
Thanks: 42
Thanked 9 Times in 8 Posts
Meet the Schloerwagen! (and a question for aeroheads)





i'm sure some of you guys are familiar with this aero beauty! the "Pillbug Car" was built in 1939, based off of a mercedes-benz 170H.

i wonder why they didn't go for a more conicular, graduated nose. perhaps it would've been too long? actually, this brings a question to my mind... would it be better, aerodynamically, for a car to have EITHER a gradual front end-nose cone type setup OR one with a boat tail on the rear end? (assuming that both would be built to maximum aerodynamic potential?)

in short, does the front or rear end of a vehicle hold more potential, in aero regards?

also check out more pics of the Schloerwagen at the following link:
The Schloerwagen or "Pillbug" car Retronaut | Retronaut - See the past like you wouldn't believe.

  Reply With Quote
The Following 2 Users Say Thank You to Mira For This Useful Post:
aerohead (08-01-2013), mikeyjd (08-05-2013)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-31-2013, 10:02 PM   #2 (permalink)
Master EcoModder
 
NeilBlanchard's Avatar
 
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,892

Mica Blue - '05 Scion xA RS 2.0
Team Toyota
90 day: 42.48 mpg (US)

Forest - '15 Nissan Leaf S
Team Nissan
90 day: 156.46 mpg (US)

Number 7 - '15 VW e-Golf SEL
TEAM VW AUDI Group
90 day: 155.81 mpg (US)
Thanks: 3,440
Thanked 2,921 Times in 1,830 Posts
Yup, we have seen it for sure! A search here on EM for Schlörwagen:

http://ecomodder.com/forum/showthrea...30s-325-2.html

http://ecomodder.com/forum/showthrea...30s-325-6.html

http://ecomodder.com/forum/showthrea...tml#post252228

http://ecomodder.com/forum/showthrea...6-a-13198.html

http://ecomodder.com/forum/showthrea...tml#post286943

A blunt nose like the Schlörwagen is better for low drag than a pointier nose. This too has been discussed many times here on EM.
__________________
Sincerely, Neil

http://neilblanchard.blogspot.com/

Last edited by NeilBlanchard; 08-01-2013 at 08:45 AM.. Reason: typo
  Reply With Quote
The Following 2 Users Say Thank You to NeilBlanchard For This Useful Post:
aerohead (08-01-2013), JasonG (08-01-2013)
Old 07-31-2013, 10:25 PM   #3 (permalink)
Aerodynamics rules
 
Viturro's Avatar
 
Join Date: Feb 2013
Location: Argentina Bs. As.
Posts: 63
Thanks: 9
Thanked 1 Time in 1 Post
I don't agree... i mean, the fastest cars (salt lake turbine) and fast planes uses cone noses... why you say that is better like that?
  Reply With Quote
The Following User Says Thank You to Viturro For This Useful Post:
aerohead (08-01-2013)
Old 07-31-2013, 11:02 PM   #4 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,761

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,548 Times in 2,215 Posts
Dammit, not this again.
__________________


  Reply With Quote
The Following 5 Users Say Thank You to Frank Lee For This Useful Post:
aerohead (08-01-2013), Cd (08-01-2013), freebeard (08-01-2013), JasonG (08-01-2013), Xist (09-25-2015)
Old 08-01-2013, 08:44 AM   #5 (permalink)
Master EcoModder
 
NeilBlanchard's Avatar
 
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,892

Mica Blue - '05 Scion xA RS 2.0
Team Toyota
90 day: 42.48 mpg (US)

Forest - '15 Nissan Leaf S
Team Nissan
90 day: 156.46 mpg (US)

Number 7 - '15 VW e-Golf SEL
TEAM VW AUDI Group
90 day: 155.81 mpg (US)
Thanks: 3,440
Thanked 2,921 Times in 1,830 Posts
Above 250MPH is different than "normal" speeds - aerodynamic "rules" are different above or below ~250MPH.
__________________
Sincerely, Neil

http://neilblanchard.blogspot.com/
  Reply With Quote
The Following 3 Users Say Thank You to NeilBlanchard For This Useful Post:
aerohead (08-01-2013), JasonG (08-01-2013), Xist (09-25-2015)
Old 08-01-2013, 07:03 PM   #6 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 13,460
Thanks: 21,447
Thanked 6,489 Times in 4,055 Posts
nose

Quote:
Originally Posted by connorkeyser View Post
so I should abandon my nose cone plans?? hmm.
*There's a couple schools of thought:
1) Do all the streamlining at the front and minimize the aft-body.Since 1974 I've only run across two studies where emphasis was concentrated at the nose.
*Eiffel studied what I call the Parisian ice cream cone (simply because it looks like one),with a convex hemispherical nose integrated directly into a conical tail,angled at 20-degrees to the longitudinal centerline.
*Dropping the cone tail first off his Tower,he measured Cd 0.18.
*Dropping it ice cream first,it recorded Cd 0.09.
*Baron Reinhard Koenig-Fachsenfeld,in the Technical University of Stuttgart's aeronautical wind tunnel studied a streamline body of revolution of L/D= 6:1.
*he ran it head-first and tail first.
*Tail-first it recorded Cd 0.55.
*Head-first it recorded Cd 0.45.
*As an automobile,running tail-first (or a reverse-Template),with wheels,it would have a drag minimum of Cd 0.142 with 'best' L/D ratio.
--------------------------------------------------------------------------
So it's possible to make a car of Cd 0.142 with most of the streamlining out front.The catch is that any windshield sloped to respect the tail-first contour would be slanted back so steeply that you'd never be able to see out of it.Something the HONDA HAWK team ran into at Bonneville during their LSR attempt.
The 1978 Volkswagen ARVW canopy delivered carnival 'fun-house' optical qualities for one auto journalist who drove it at VW's proving grounds.
And nothing in the published literature suggests that you could take any liberties at all with the nose.It would HAVE to be constructed exactly like a reverse-'Template'.
-------------------------------------------------------------------------
2) Conventional wisdom for sub-sonic bluff-body road vehicle aerodynamic streamlining is to have a convex-hemispherical nose-based forebody,combined with a long,tapering teardrop tail aft-body.
-------------------------------------------------------------------------
Wolf Heinrich Hucho was directly involved in the development of VW's Vanagon.In his book he has a drag table illustrating how little leading edge radius it took to achieve the lowest drag.Once they chiseled the clay a bit,no amount of further rounding produced any lower Cd.This was for zero-yaw of course.Later in his book he shows the 'bulbous' nose as the low drag champ for crosswinds,which is where we do most of our driving.
*The piece de resistance is in another table in which the entire drag of the nose constitutes a whopping 5.88% of the vehicles overall drag.Skin friction is 22%.The rest is aft-body drag.Over 72%.
-------------------------------------------------------------------------
This is an extremely long way of saying that your energies might be better spent working on the back of the car.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
The Following 6 Users Say Thank You to aerohead For This Useful Post:
COcyclist (02-05-2015), JasonG (08-01-2013), mikeyjd (08-05-2013), Mira (08-02-2013), UFO (08-09-2013), Xist (09-25-2015)
Old 08-01-2013, 07:27 PM   #7 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 13,460
Thanks: 21,447
Thanked 6,489 Times in 4,055 Posts
fastest

Quote:
Originally Posted by Viturro View Post
I don't agree... i mean, the fastest cars (salt lake turbine) and fast planes uses cone noses... why you say that is better like that?
You've provided the context under which the cone would have the advantage.
At the trans-sonic and supersonic velocities of the LSR vehicles,the shockwaves generated on a 'bulbous' nose would block momentum interchange into the boundary layer,triggering separation right there,with no re-attachment.Which could be catastrophic.The 'ogival',or pointy nose is designed to squash the shockwaves,allowing clean flow to the rear,where fins can keep the CP behind the CG.
--------------------------------------------------------------------------
For daily commuting though,as others have mentioned,the pilbug's nose is actually ideal.Koenig-Fachsenfeld has a photo of it in the Stuttgart wind tunnel and the smoke flow over it could not be improved upon.It does have a robust stagnation area but that's great for the cooling system and cabin ventilation.
With the Ludwig Prandtl' flow lines of discontinuity the streamline filaments are moving as if the nose projected to a point anyway.
It's 'weird' but it's the way of the world.
PS if you'll do a GOOGLE Image search with Windkanal,you'll eventually get to a color photo of the Schl'o'rwagen model under smoke and green light in the wind tunnel.It's pretty sweet!
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/

Last edited by aerohead; 08-01-2013 at 07:33 PM.. Reason: ad PS
  Reply With Quote
The Following 4 Users Say Thank You to aerohead For This Useful Post:
BamZipPow (08-03-2013), Mira (08-02-2013), Viturro (08-03-2013), Xist (09-25-2015)
Old 08-01-2013, 07:48 PM   #8 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,761

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,548 Times in 2,215 Posts
__________________


  Reply With Quote
The Following 6 Users Say Thank You to Frank Lee For This Useful Post:
aerohead (08-01-2013), BamZipPow (08-03-2013), COcyclist (02-05-2015), JasonG (08-01-2013), mikeyjd (08-05-2013), Mira (08-02-2013)
Old 08-01-2013, 07:58 PM   #9 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 13,460
Thanks: 21,447
Thanked 6,489 Times in 4,055 Posts
wind tunnel pic

Thanks Frank! That be de animal!
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 08-02-2013, 03:18 AM   #10 (permalink)
Captain Planet
 
Join Date: Jul 2012
Location: Louisiana
Posts: 50

Smokey - '00 Honda Civic DX
Team Honda
90 day: 38.53 mpg (US)

Jade - '02 Acura RSX Type S
Thanks: 42
Thanked 9 Times in 8 Posts
thanks aerohead! this is all great info

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com