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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-24-2013, 03:34 PM   #151 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 10,838

CM400E - '81 Honda CM400E
90 day: 58.68 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
90 day: 45.07 mpg (US)
Thanks: 2,200
Thanked 2,304 Times in 1,394 Posts
Both of those images are incorrect. Check the instructions on how to do it. The apex of the roof line should meet the apex of the aero template. You should end up with something between the two images you have.

Something more like this...


Attached Thumbnails
Click image for larger version

Name:	mustang.jpg
Views:	572
Size:	86.3 KB
ID:	13993  
__________________
Current project: Help me kill my alternator - it is stubborn and won't die
  Reply With Quote
The Following User Says Thank You to Daox For This Useful Post:
aerohead (10-24-2013)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 10-25-2013, 01:03 PM   #152 (permalink)
EcoModder
 
Join Date: Jul 2008
Location: North Central Alabama
Posts: 569

Big Salsa - '04 Toyota Sienna LE

Silver - '10 Toyota Prius III
Thanks: 107
Thanked 116 Times in 67 Posts
I don't know if it's been discussed (I didn't read all the posts), but how hard would it be to add a "rotate" function for the original image? I guess it would be the same difference to rotate the template, but I think it would be useful seeing as how not all pictures are taken flat, and not all configurations can be recreated.
__________________
  Reply With Quote
Old 10-30-2013, 04:37 PM   #153 (permalink)
Permanent Lurker
 
seifrob's Avatar
 
Join Date: May 2011
Location: Czechoslovakia (sort of), Europe
Posts: 322

Dáčenka - '10 Dacia / Renault Logan MCV 1.5 dCi (X90 k9k)
90 day: 47.08 mpg (US)
Thanks: 125
Thanked 172 Times in 73 Posts
It has been considered, but rejected for simplicity and reasons.

Although it is possible (see here: How to Rotate Images Using JavaScript (JavaScript & Canvas). Cross-browser Solution. — ajaxBlender.com), it would complicate the code and won't be much use (you can rotate only in certain steps). Much better solution (from my point of view) is:
a) photograph level pictures
b) Use straighten/level tool that you find in almost any good photo browser/editor. (Google Picasa, IrfanView etc.) - thus you will have straightened picture for future use.

once you have picture with level ground, you can freely use it
  Reply With Quote
The Following User Says Thank You to seifrob For This Useful Post:
aerohead (10-31-2013)
Old 07-05-2014, 10:51 PM   #154 (permalink)
EcoModding Apprentice
 
ERTW's Avatar
 
Join Date: Jan 2012
Location: Toronto
Posts: 120

Bu - '08 Chevrolet Malibu LS
90 day: 32.29 mpg (US)
Thanks: 50
Thanked 65 Times in 31 Posts
Well, I was matching up the GM Precept with the template. At first glance it looks like it's way off...not even approaching the 50% mark. But how come it's one of the most aerodynamic cars on the planet (Cd = 0.174)...which still looks like a car, can fit four people comfortably, and looks like it can be mass produced? Note that it only uses half wheel covers, and non-dished wheels.

I changed Aerohead's spherical nose to a 1.36:1 ellipsoid two years ago. Far short of the 2.5:1 ellipse that pre-war research shows. Sharks and boxfish have tapered noses. It follows the Precept very closely.

I tried many ellipses at the rear and it didn't conform to any. Next, I lined up the rear half of the template and started shrinking it. The drawing is exactly 1/2 scale. I was surprised, and elated. So the template doesn't just work at full scale. Again, my hat is off to Aerohead

edit: Kachi22i scaled down the template may 24, 2013...but you DON"T scale down your success I believe I know why it works on the Precept, and not so much on the Porsche 911.
Attached Thumbnails
Click image for larger version

Name:	precept template.jpg
Views:	57
Size:	58.8 KB
ID:	15325  
__________________
“Soft shapes follow us through life. Nature does not make angles. Hips and bellies and breasts — all the best designers have to do with erotic shapes and fluidity of form.” - Luigi Colani

Last edited by ERTW; 07-05-2014 at 11:08 PM.. Reason: props to kachi22i
  Reply With Quote
The Following User Says Thank You to ERTW For This Useful Post:
aerohead (07-07-2014)
Old 07-07-2014, 06:03 PM   #155 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 9,982
Thanks: 14,969
Thanked 5,298 Times in 3,107 Posts
Precept

This is what I have for the Precept.Originally,GM claimed Cd 0.163 for this concept.

PS,my image is not in true-length.It's the only thing that I have which is close.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/

Last edited by aerohead; 07-07-2014 at 06:05 PM.. Reason: add PS
  Reply With Quote
Old 07-07-2014, 08:52 PM   #156 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 7,586

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 37.81 mpg (US)
Thanks: 4,780
Thanked 1,440 Times in 1,089 Posts
Common procedure around here is to post an incorrect image and then someone else will go through a great deal of effort to fix it for you.

This is what I use: GIMP - Downloads

It is overkill, though, Windows Paint has all of the other features that I really need.

Does anyone know of a simpler program?
  Reply With Quote
Old 07-08-2014, 12:04 AM   #157 (permalink)
EcoModding Apprentice
 
ERTW's Avatar
 
Join Date: Jan 2012
Location: Toronto
Posts: 120

Bu - '08 Chevrolet Malibu LS
90 day: 32.29 mpg (US)
Thanks: 50
Thanked 65 Times in 31 Posts
Quote:
Originally Posted by aerohead View Post
This is what I have for the Precept.Originally,GM claimed Cd 0.163 for this concept.

PS,my image is not in true-length.It's the only thing that I have which is close.
Thanks Aerohead. I see that number quoted most often. I read a web article, and for the life of me I can't find it again. It details the shape development. Iirc the wizards who designed the body only had FOUR hours in the wind tunnel. It started off around 0.15 and it crept up after adding body gaps and such. I recall the .17x figure.

3/4 views look cool. However, three orthographic views allows anyone to create an accurate 3D model. Precept photos are rare, and rarely helpful. I can't even find basic dimensions. I am very eager to look more closely at its shape...

Fwiw mercedes claims that their bionic car can potentially get down to 0.095. Isn't that the ideal land vehicle Cd?
__________________
“Soft shapes follow us through life. Nature does not make angles. Hips and bellies and breasts — all the best designers have to do with erotic shapes and fluidity of form.” - Luigi Colani
  Reply With Quote
Old 07-08-2014, 06:14 PM   #158 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 9,982
Thanks: 14,969
Thanked 5,298 Times in 3,107 Posts
ideal

Quote:
Originally Posted by ERTW View Post
Thanks Aerohead. I see that number quoted most often. I read a web article, and for the life of me I can't find it again. It details the shape development. Iirc the wizards who designed the body only had FOUR hours in the wind tunnel. It started off around 0.15 and it crept up after adding body gaps and such. I recall the .17x figure.

3/4 views look cool. However, three orthographic views allows anyone to create an accurate 3D model. Precept photos are rare, and rarely helpful. I can't even find basic dimensions. I am very eager to look more closely at its shape...

Fwiw mercedes claims that their bionic car can potentially get down to 0.095. Isn't that the ideal land vehicle Cd?
Hucho has suggested that with extremely careful integration of the wheels,that we might approach the Cd of the basic body of 0.08.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 08-06-2014, 12:29 PM   #159 (permalink)
Master EcoModder
 
aardvarcus's Avatar
 
Join Date: Apr 2012
Location: Evensville, TN
Posts: 543

Deep Blue - '94 GMC Suburban K2500 SLE
90 day: 23.75 mpg (US)

Griffin (T4R) - '99 Toyota 4Runner SR5
90 day: 24.95 mpg (US)
Thanks: 189
Thanked 435 Times in 239 Posts
Quote:
Originally Posted by Xist View Post
Common procedure around here is to post an incorrect image and then someone else will go through a great deal of effort to fix it for you.

This is what I use: GIMP - Downloads

It is overkill, though, Windows Paint has all of the other features that I really need.

Does anyone know of a simpler program?
Microsoft PowerPoint 2010 is what I use. Put the picture of the vehicle and the template on one slide. Scale and rotate the car and/or template to match using the built in tools. The magic is that when you start dragging the pictures, they go half transparent automatically. Drag the photo of the template over the photo of the vehicle. Move it with your cursor till it lines up, then before you let go of the image, hit the print screen button. Paste the screenshot on a new slide or in paint, crop the border, and you are done.
Attached Thumbnails
Click image for larger version

Name:	PPT use.jpg
Views:	76
Size:	75.3 KB
ID:	15500  
  Reply With Quote
Old 09-22-2014, 08:27 PM   #160 (permalink)
Karmann Eclectric
 
jray3's Avatar
 
Join Date: Feb 2010
Location: Graham, WA
Posts: 165

Odysseus - '00 Honda Odyssey

MR BEAN - '12 Mitsubishi i-MiEV SE

Karmann Eclectric - '71 VW Karmann Ghia Electric Conversion

BOB - '87 Ford 250 Lariat ext cab
Thanks: 9
Thanked 88 Times in 50 Posts
Converting the template into an actual dimensoned pattern......

I'd like to build a trailer shell following the template, but with flat panels that are precut to shape, zeppelin-style. Undecided on a riveted aluminum skin vs foam panels to then glass over, or soaking an inflated envelope with resin, then building it up, but am leaning towards aluminum (possibly with a spray-foam interior layer to stiffen and insulate).
So far I've struck out on finding a pattern to scale up. Closest thing is these hot air balloon panels from a crafter's blog (don't laugh if you click through).
http://prudentbaby.com/wp-content/up...ir-balloon.pdf

DIY Hot Air Balloon Mobile (Free Pattern!) | Pretty Prudent

This company gets me close, have requested a design cost estimate....
APEX Balloons - Hot Air Balloon Manufacturer, Hot Air Airships, Balloon Repair Station

Any of you design wizards already cracked this nut?

__________________
2012 Mitsubishi i-MiEV, 112 MPGe
2000 Honda Odyssey
1987 F250 Diesel, 6.9L IDI, goes on anything greasy
1983 Grumman Kurbwatt, 170 kW "Gone Postal" twin
1983 Mazda RX-7 electric, 48 kW car show cruiser
1971 VW Karmann Ghia electric, 300 kW tire-smoker
1965 VW Karmann Ghia cabriolet, 1600cc
Have driven over 100,000 all-electric miles!
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com