Optimal Car Shape - Fuelly Forums

Click here to see important news regarding the aCar App

Reply
 
Thread Tools Display Modes
 
Old 03-19-2009, 08:59 AM   #1
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
Optimal Car Shape

I have read many times that the teardrop shape is the ultimate for car aerodynamics. I assume that reflects a car with two people sitting side by side, because the ultimate projectile shape is a cylinder with points on both ends. Artillery shells use a gas generator to virtually create the rear tail. Now, I can see it being pretty tough to make a car in that form. Have two wheels and outriggers that fold out only at low speeds? If you put wheels out all the time you compromise the shape. I suppose you could also approach it like a catamaran and have two connected together. Be a great way to get privacy from the kids! I apologize for my limited drawing skills. Couldn't seem to get the picture url link to work in this post.
__________________

__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 03-19-2009, 10:54 AM   #2
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
I wonder if the much lower speeds seen by cars accounts for the teardrop shape making sense?
__________________

__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 03-19-2009, 11:01 AM   #3
Registered Member
 
Join Date: Nov 2007
Posts: 1,111
Country: United States
Send a message via AIM to dkjones96
I'd like to see where someone did an aerodynamics study to show that the teardrop shape is the most efficient. The teardrop shape would create a high pressure area in front of it as opposed to cutting through like a cylinder with tapered ends.
__________________
- Kyle
dkjones96 is offline   Reply With Quote
Old 03-19-2009, 11:03 AM   #4
Registered Member
 
GasSavers_BEEF's Avatar
 
Join Date: Apr 2008
Posts: 1,831
if you look at the fuselage of an airplane, it has the same shape. you have to look at it from a different angle though. tha aptera tapers from top to bottom and bottom to top. airplanes taper on the sides more than the top. of course all of this going front to back.

I have heard that the optimum angle is a 10 degree grade or slope.

*edit* also if you had to taper in the front and the back, the vehicle would have to be extemely long to have any room inside.
__________________
Be the change you wish to see in the world
--Mahatma Gandhi



GasSavers_BEEF is offline   Reply With Quote
Old 03-19-2009, 11:16 AM   #5
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
Quote:
Originally Posted by BEEF View Post
*edit* also if you had to taper in the front and the back, the vehicle would have to be extemely long to have any room inside.
Sure would. That's why thought the catamaran arrangement would make more sense.
__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 03-19-2009, 11:24 AM   #6
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
I'm mostly just shooting the breeze. Besides, I like to think on a problem before checking out the established research. Otherwise, you can fall into the trap of not considering things that haven't come before.

Actually, what I usually do is this:

If I think the problem has a very optimal solution, I just go straight for the standard solution. If I think there's still room for improvement, I do the brainstorming first, researching second approach.

As cars are a compromise of aerodynamics with practicality, it's far from cut and dry.
__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 03-19-2009, 11:45 AM   #7
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
I once spent a week reading research for hydrogen as the ideal jet fuel. I had no possible use for it, but was living in the same city as my alma mater and had free access to their science library. Those were the days!
__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 03-19-2009, 11:48 AM   #8
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
Ever hear the joke about the difference between engineers and physicists?

A physicist will spend all day deriving a formula he could've looked up in five minutes. An engineer will spend all day looking for someone to tell him a formula he could've derived himself in five minutes.

I try to walk somewhere in the middle, but tend towards the physicist end a bit (ironic since I'm an engineer).
__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 04-18-2009, 09:18 PM   #9
Registered Member
 
Join Date: Mar 2009
Posts: 1,139
Country: United States
Seems like some posts have gone missing in this thread...weird.

I talked to my uncle who has a lot of wind tunnel testing knowledge and he agreed that the shape I was discussing would work pretty well (assuming the weird configuration could be made practical for the powertrain and passengers), but when I did a little measuring to see what a catamaran style car would look like it became evident pretty quickly that it's just not wide enough to warrant it, at least for four occupants. Planes and boats, sure. I once saw a race car that almost had this approach, as it just had a cockpit bubble on the driver's side. You'd have to do something similar: two people on one side, and the trunk and engine on the other or something. Very odd configuration indeed with better options (center hump, for example) particularly if you're comfortable with three wheels. If I had some 3d software I'd have done up a quick model, because the resulting vehicle is pretty amusing in its impracticality. Figuring out how to make a powertrain and balance work was fun.
__________________


Main Entry: co de pen dence - see codependency
co de pen den cy
Pronunciation: \kō-di-ˈpen-dən(t)-sē\
Function: noun
Date: 1979

: a psychological condition or a relationship in which a person is controlled or manipulated by another who is affected with a pathological condition (as an addiction to alcohol or heroin) ; broadly : dependence on the needs of or control by another
GasSavers_maximilian is offline   Reply With Quote
Old 04-19-2009, 07:11 PM   #10
Registered Member
 
Join Date: Dec 2007
Posts: 170
Country: United States
In the 1952 there was a land speed record attempt by Piero Taruffi in a twin boom vehicle (catamaran shape) called a TARF I think.

An interesting design study for those interested.

Some details and a cut away drawing here:
http://jalopnik.com/photogallery/dblbullet/1003234992

Cheers , Pete.
__________________

GasSavers_Pete is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bad MPG during new car break-in period magnus919 General Fuel Topics 7 04-12-2012 08:13 PM
Fuelly Android App - eehokie Fuelly Web Support and Community News 2 07-14-2010 08:59 PM
Motor Home tab Buffalobilly Fuelly Web Support and Community News 0 03-20-2009 09:13 AM
Car Magazines: Do You Subscribe? rh77 General Discussion (Off-Topic) 28 06-14-2008 10:18 PM
96-98 civic hx mt engine wiring harness pappajohn Wanted to Buy 4 03-10-2007 04:17 AM

» Fuelly iOS Apps
Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 07:36 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.