Why is teardrop the most sreamlined?

[bschloop]

the best way to understand is to do. find or make a wind tunnel and try all the shapes you can think of at normal vehicle windspeeds. when a vehicle is designed this is what is done.

also, most vehicle shapes are compromises. the best shape for a bike won't work for a car, and vice-versa. consideration must be made for the person/people within.

[Frank Lee]

Re: pointy: keep in mind there are several TYPES of aero drag; for example a super sleek pointy shape might have lower FORM drag than a teardrop but because of the increase in surface area- if the shapes compared have equal volume- the pointy shape with the greater surface area suffers from increase SKIN drag such that the overall drag is greater.

[Cd]

Originally Posted by minimac

I'm really late to coming around to these streamlining discussions, and I understand a lot of work has been done by a lot of people, but why does this shape have to be accepted as being best? Airplanes go through the air well and are not that shape. Rockets are shot into space and are not that shape. Land speed vehicles are usually not that shape, nor are missiles. I think that would prove that the best shape for cutting air would be a pointy cylinder. What am I missing?

and then these as well :

[Cd]

Correct me if i'm wrong, but the reason that jets and rockets don't look so much like a teardrop at the rear is also because this is where the exhaust gasses come out, and therefore there is no need to streamline for less turbulence.

Example here being the SR-71 - Look at the rear appendage which tapers off like a teardrop, versus the tips of the engines ( and yes the SR-71 is pointy because it goes Mach 3 . Commercial jets have rounded 'blunt ' fronts because they do not break the sound barrier. )



But then, note how the Space Shuttle has a blunt front.
Makes it all confusing doesn't it ?

[MisterInnovation]

You know you are into streamlining when you read the thread title and you think
"There is only one streamlined shape and this is it. Round at the front, pointy at the rear."

[MisterInnovation]

The boxfish shape is also very streamlined. However I cannot for the life of me find a 3d model of one.

[minimac]

I did read a little bit about the work Mercedes did( Bionic) and the boxfish. That would seem to be close to the optimum shape for a car.
The Bionic Car project - Image 12 of 12
This would make it seem that it is better to 'bend' the air(image #2) than to cut through it for a passenger vehicle. Formula One or Indy car designers feel it's better to cut through the air, evidenced by the pointy fronts and rounded sides. I was thinking that, for a motorcycle( being relatively tall, short, and narrow) a modified wedge-low pointy front, wide@ the beltline and tapering top and bottom(all sharp angles)- would be best. Now I have no clue!!!

[NeilBlanchard]

Biomimicry is something we should look at a lot more. This is the starting point for my CarBEN EV5 - the first Boxfish/Bionic models with 4 wheels:

The Bionic Car project - Image 3 of 12

[Cd]

Also, note that the Bionic car does not have a pointed front end, but rather rounded and has a good amount of slope like a teardrop.

Here is the top view:



The original more streamlined design ( which is Neils inspiration above ) was even more
teardrop like in appearance :

[minimac]

Originally Posted by Cd

Also, note that the Bionic car does not have a pointed front end, but rather rounded and has a good amount of slope like a teardrop.

The original more streamlined design ( which is Neils inspiration above ) was even more teardrop like in appearance

Also note that it is a CAR! I'm thinking a motorcycle here.....