Rounded forms not necessarily the most aero

[groar]

Particularly like this sentence :

Some cars, including Porsches, have famously proved more aerodynamic when turned tail-first in the wind tunnel.

It's when I read a sentence talking about that, that I made my Mini open tail as it was too rounded.

This article reminds me this one : Toyota goes its own way with green designs

September 25, 2008 5:00 AM PDT
Toyota goes its own way with green designs
by Automotive News

(Credit: Automotive News)

TOYOTA CITY, Japan -- For a taste of future fuel-efficient styling from Toyota, go no further than the FT-HS hybrid sports car. It is counterintuitive, high-tech, and unconventional.

But global design chief Wahei Hirai says the FT-HS will form the foundation for all future styling as Toyota Motor Corp. tries to squeeze every mile from a gallon of gasoline.

The angular, low-slung FT-HS is just a concept. But its design elements already are incorporated into Toyota's iQ minicar, which will be on the streets in Japan and Europe in five months.

The new styling also will surface in upcoming hybrids, where green-conscious customers appreciate avant-garde looks.

From a design point of view, the goal is to make air-slicing cars even more slippery.

"Aerodynamics have always been important, but today they are getting more and more important," Hirai says. "We are paying very serious attention to very small details."

Four new approaches are key to Toyota's new styling trend:

1. Angular front corners for smoother airflow along the car's side.

2. A lower grille, for reduced air resistance.

3. Forward placement of the front bumper to act like an air dam.

4. Triangular, Prius-like side silhouettes for reduced drag.

The corner treatment is perhaps the most counterintuitive. Instead of using rounded front corners, Toyota is moving toward angled ones that provide a flush surface in front of the wheel. Toyota says this helps stabilize air flow and reduce turbulence around the car.

Toyota calls the treatment the Aerocorner. On the FT-HS, it is achieved by bringing the front fender forward and then making a sharp break. On the iQ, it comes from adding a corner bulge.

"What we want to do is bring the air under control before it gets to the wheelhouse," says Simon Humphries, general manager for global design. "So having a flat area and a sharp corner is actually much better from an aerodynamic standpoint than just having a round front end."

It is difficult to measure the precise benefits of the Aerocorner, but Toyota estimates that, all things being equal, it can improve a car's drag coefficient by up to 0.03 points.

Toyota is taking another unconventional step by sealing the upper front grille as much as possible and making the lower grille the main air intake for cooling the engine. The reason: a gaping hole up high causes too much drag.

Placing the grille lower not only streamlines the front fascia, but it also allows designers to make the grille opening smaller. This is because the air pressure is higher closer to the ground.

"Up until now, the upper grille has always been prioritized," Humphries says. "What we're doing here now with these cars is to change the priority, and that's quite a radical step."

The FT-HS doesn't even have an upper grille, while the iQ has a razor-thin slit.

Meanwhile, Toyota is bringing the lower bumper forward so the side silhouette is more wedge-shaped than bullet-shaped. The idea is to channel the air around the car, instead of under.

Hirai says designs also will continue to emulate the Prius-like triangular side view. That profile helps give the popular hybrid vehicle a drag coefficient of 0.26, the lowest in Toyota's fleet.

"The Prius is so good for aerodynamics, it is very difficult to change that silhouette to get something better," Hirai says. "The Prius is already very close to the best silhouette."

Nevertheless, Hirai says to expect an even lower drag resistance on the third generation of the Prius, which arrives next year.

"It has to be," he says. "We worked very hard."

Many of the new design treatments will debut in upcoming hybrid vehicles, Toyota says. After they gain acceptance from the public, the styling will migrate to other models.

"As long as these design treatments are good for aerodynamics, why not for the Prius, because the Prius has to be the leader," Hirai says. "The Prius needs a more symbolic or advanced image as an exclusive car. Sometimes those advanced designs won't be understood by everyone."

(Via: Automotive News)

I found it when I tried to find a way to improve the sharp mod in front of Mégane :
http://ecomodder.com/forum/showthrea...tml#post177318
Which is only the result of having feet in place of my hands

To help me improving my "aerocorners", a sidewalk removed the uglyteeth... I was thinking about putting a half tube vertically in front of the corner so its tangent is aligned with the side of the corner.
The question was : what diameter should have that half tube ?
I looked at newer cars in the streets and parking lots. Not only the Prius III and the IQ have these aerocorners, but also the Insight II and lots of compact cars (often not from top to bottom), or at least the rounded part have a very small diameter (a few inches).

After remembering this article and the shapes of PriusIII and InsightII I decided to let the front of Mégane as-is, proud to have cutting-edge aerodynamic engineering on my car

Denis.

[aerohead]

Originally Posted by instarx

Gee, aerohaed. When I posted this exact article to EM in 2008 because I thought people might like to read about new trends in automotive edge design you thought it was useless, deceptive, poorly written and had absolutely nothing new in it (you so kindly informed me that there is nothing new in aerodynamics because it has been fully understood since 1800). It was my first original post to EM and you skewered me for being so naive to think it might be of interest.



Nice to know that you now think the article was a "game changer" and "moves the whole issue of aerodynamic drag further into the light." Although I won't go that far, I'm glad to know that I was right and the article was interesting after all.

instarx,please accept my apology,I was under the understanding that Frank's article was 'current.'
In the context of broader knowledge the article might be useless,deceptive,and poorly written although having an understanding of journalist-speak I no longer have to forgive their ignorance of their subject matter.
Personally,I've never had a journalist 'get it right,' so my expectations are reduced to zero now that I better understand the media.
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It was never my intent to 'skewer' you nor anyone who contributes.My angst was directed at the article,not the messenger.Again,my apology.
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It IS my opinion that the article brings very little new information to the plate,and that must be taken within the context that I've been actively looking for 'something new' for 35 years.
The article brings nothing beyond what Hucho et al reported on back in 1976.
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When Ryland asked specifically about the 'box' I attempted to bring a historical context to his query.
As far as fluid mechanics goes,there is very little new under the sun.You will witness that all high performance structures share a resemblance to Sir George Caylay's trout.If all of Leonardo da Vinci's papers had survived we could probably move the timeline back to the 1500s.Or dugout canoes,2000 years ago.Samarian naval architecture?
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If The New York Times printed a rebuttal to the article that would be great.Short of that,whenever I run across 'media' accounts related to aerodynamics I feel a personal responsibility to throw a caution flag on the play if I think they have mis-stepped the physical world.
The US is only losing $38-billion a year to aerodynamic drag.Who's the Times to give a care.They COULD make a difference but they have no obligation to do so.

[aerohead]

Originally Posted by euromodder

The hallmark of great designers is how they design common things.
How they add their own touch to what are essentially the same objects, in order to make them stand out.

Toss thousands of laptop computers together.
They'll all have the same basic components, and will all have the same basic layout.
Yet it won't be hard to pick the Apple offerings out of that pile.

The same can be done when starting a design with the teardrop shape.
The basic teardrop layout offers plenty of scope for individual design features.

No other consumer product,as the automobile,has such planetary implications when it comes to 'design.'
It's my opinion that 'stylists' should not possess the power to influence such a technology.

[aerohead]

Originally Posted by ChazInMT

You gotta credit Instarx on this, he has handled this much better than I'd have.

http://ecomodder.com/forum/showthrea...amic-6483.html

I particularly like post #8.

#20 is my response to #8

[Frank Lee]

Originally Posted by aerohead

It's my opinion that 'stylists' should not possess the power to influence such a technology.

Oh no, I disagree! Look at the VW 1L for example: The first one was clearly done by engineers while the later ones benefitted greatly from the stylist's touch.




It can be argued that it is the stylists, as much or more so than the engineers, that really got things going as far as automotive streamlining back in the Art Deco movement, when EVERYTHING had to be "streamlined".

Who can argue against stylists when they create something awesome like this:



... sleeker than the "engineered" cars of the time.

The key is to have stylists that are savvy to engineering; stylists and engineers that work together well as a team; management and marketing departments that allow aerodynamics to be a priority; or all of the above.

But purely engineer designed stuff is oftentimes... well.... unappealing.

[Sularus]

Frank Lee has a point. Look at the USAF F-117 stealth fighter. The plane's body was designed entirely by electronics engineers for radio wave reflectivity. It is horrendous looking. I think stylists guided, or at least babysat, by engineers is how we get efficient, good looking vehicles.

J

[euromodder]

Originally Posted by Frank Lee

It can be argued that it is the stylists, as much or more so than the engineers, that really got things going as far as automotive streamlining back in the Art Deco movement, when EVERYTHING had to be "streamlined".

Exactly.
Streamlining was once a big design trend - even if they didn't always have the technology to check it or really make it work.

There's really no reason why this trend shouldn't come back.
It must come back to make our transports more efficient, no matter what we power them with.

[euromodder]

Originally Posted by Sularus

Frank Lee has a point. Look at the USAF F-117 stealth fighter. The plane's body was designed entirely by electronics engineers for radio wave reflectivity. It is horrendous looking.

Yet the far more appealing F-22 does better on all fronts - esthetics included.

[BHarvey]

Originally Posted by euromodder

Yet the far more appealing F-22 does better on all fronts - esthetics included.

But even the F22 has a long way to go to approach the look of the F16.
If a jet can be sexy, the F16 is it...

[AeroModder]

Engineers design shape, stylists use the shape as a blank canvas. I think that's a fair comprimise.