What woud be the ,optimum car nose shape given what is known about air curtains, undertrays, etc?e

[Otto]

Starting with a clean piece of paper and given what is known about air curtains, undertrays, nose stagnation and compression of airflow, etc., and given conventional car shape, what would such a face look like?

In other words, if Hucho, Julian Edgar, NASA nerds, and the best minds of Porsche, BMW, Audi, Toyota, and Ferarri all got together with the best minds on this website, what would they come up with, vis most efficient car nose shape?

[freebeard]

It depends on the design brief/use case. Things like lighting, cooling,etc. The big one is driver sight-lines. A flat windshield at 90 degrees to sight-line is best, sloped and curved windshields are subject to refraction and glare.

The example uses flat faceted panes, while the rest of the body can be compound curved. The two forward facing hexagons could be flattened, enabling a Luigi Colani spinning windshield wiper. The front wheels are held back where leading and trailing spats are possible. The overall form is your nominal solar racer inflated for interior volume.

[gingwhaa]

Probably a Halibut shape....

[freebeard]

Boxfish

[kach22i]

I guess it's a fair question.

Design by committee is how the camel got designed though.

[aerohead]

Originally Posted by Otto

Starting with a clean piece of paper and given what is known about air curtains, undertrays, nose stagnation and compression of airflow, etc., and given conventional car shape, what would such a face look like?

In other words, if Hucho, Julian Edgar, NASA nerds, and the best minds of Porsche, BMW, Audi, Toyota, and Ferarri all got together with the best minds on this website, what would they come up with, vis most efficient car nose shape?

It dates to World War-I.
It was on a British warplane, with forward machine gun position, and pusher-prop. They hadn't figured out yet, how to synchronize shooting bullets through the rotating propeller.
Anyway, Hucho called it both 'Optimum' and 'Ideal'. The 1922 Jaray and Klemperer basic bodies use it, Walter Lay used it in 1933, Kamm did research with it in 1935, Schl'o'rwagen 1938, Lancia Aprilla by Pininfarina 1944, 1978 Hucho basic body, SMART Fortwo, Aston Martin Cygnet, many many others have used it.
If you're not going to skirt the front wheels, then the air curtains are a palliative to the drag created by the open wheel arches.

[freebeard]

R. Buckminster Fuller got the number of wheels right.



www.washedashore.com/projects/dymax/pictures.html
Dymaxion #3 posed with Fuller's personal aircraft, a Republic Seabee. An interesting airframe that inspired Sandy Munro's aircraft design.


http://www.bubblemania.fr/dymaxion-c...ner-americain/

Lots of good pix there. The Fuller/Isamu Noguchi model:


http://www.dailyicon.net/2009/02/dym...isamu-noguchi/

[Piotrsko]

Putting it bluntly: nose shape has relationships with width, height and maximum vehicle length. Naca found that a 2" radius nose on their laminar semi symmetrical series was required for the laminar flow but mostly for stall conditions. As illustrated by the F104 wing, things get squirrelly really fast in a sharp edge wing at stall. The template addresses having a decent passenger compartment and a front mounted engine with that ugly profile otherwise you need lay flat passengers and a pancake motor.

[some_other_dave]

There is no one "ideal". If there were, it would be universally used by now.

There are a ton of different constraints that an automotive shape has to satisfy. And each choice made in one affects the possibilities for other choices. As was mentioned, the air curtain thing is pretty meaningless if you have covered or spatted wheels. And if you want more air going under the car, the nose shape will be different than if you want less going under the car. And don't forget cooling ducts and exhausts.

It gets complicated in a huge tearing hurry, and it depends rather a lot on just about every factor going into the car's design.

We have seen "good" noses, more than likely "good enough" ones, such as the well-known Template. But there isn't really any "best" one, IMHO.

-soD

[aerohead]

MetroMPG took my raw video from 2014 and created: 'Streamlined Toyota T-100 In the Wind Tunnel'.
It's right here at EcoModder.com
If you haven't seen it, it may be of value. It's got the WW-I nose on it. In 1976, Hucho called it 'Optimum', 'Ideal.'
It could use some of the airdam shaved off, maybe 25mm or so.( Unnecessary downforce ). Other than that, I'm pleased.
On some vehicles, the nose constitutes only 5% of overall drag.