Car Aerodynamics Have Stalled?

[suspectnumber961]

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"Pundits were suggesting that in the near future there would be plenty of cars with 0.25 and lower drag numbers. It seemed like a win/win change: since at speed by far the majority of power is used to push air out of the way, slipping more easily through that air results in more power available for acceleration and less overall fuel usage. And what with the huge investment in wind tunnels, the experience that aeronautical engineering could bring, and a new crop of stylists schooled in aerodynamics, well, it was all going to happen.

Except, it hasn’t."

[NeilBlanchard]

We'll see about that! ;-)

[JasonG]

There was a recent thread here about how car manufactuers used to post their cd #s.
Now it seems they stopped caring.

[ChazInMT]

This article you link to is from 2006. Having just returned from Europe, I can assure you aerodynamics are very much a concern there, many cars have slippery shapes. Here in the States, I think changes are not far behind.

[Sven7]

I'm a senior in Transportation Design at CCS in Detroit. Let me tell you in the past three years I have not heard but a few sentences about aerodynamics from any of the instructors' mouths. It's just not on America's radar. I imagine a lot of the reason for posting Cd numbers with prototypes was that gas was expensive back then. Nowadays with the neo horsepower race we as a country really don't care. We just want cars that look flashy. It's sad but true.

Edit: Let me add that it'll be at least an eight year wait if we start teaching students about aero this year. It'll take them four years to complete school and four years for the company to design and engineer the car.

That is, unless the current designers start doing aero. Then it could be 3-5 years.

[brucepick]

Originally Posted by JasonG

There was a recent thread here about how car manufactuers used to post their cd #s.
Now it seems they stopped caring.

I think the manufacturers - and more importantly the ad and TV commercial writers - don't think the buying public cares or understands. In fact most writers likely don't understand or care; they mostly were literature/arts/communications students.

But, as ChazInMT wrote, designers outside the US certainly seem to be moving in the direction of better aero. Some of their stuff eventually makes it over here.

Plus, as soon as I get my planned aero rear spoiler built, and a big sign on the car "50 mpg", EVERYONE will want one! Right now I have a "48 mpg" sign on the driver's side rear window, and I've been asked how I do it by total strangers.

[autogyro]

I found this to be the most compelling pice of data in the link:

http://autospeed.com/cms/gallery/art...w=0&a=2455&i=7

33% of the total drag (based on a soon to be produced Volvo) is produced by the cooling system. That's 2% more than the total exterior!

Of course this isn't a problem (pointed out to me in rebuke by an illustrious member of this forum), since this was completely solved by Korff a half century ago.

[gone-ot]

"...the pundits have punted!.."

[Sven7]

Originally Posted by autogyro

I found this to be the most compelling pice of data in the link:

http://autospeed.com/cms/gallery/art...w=0&a=2455&i=7

33% of the total drag (based on a soon to be produced Volvo) is produced by the cooling system. That's 2% more than the total exterior!

Of course this isn't a problem (pointed out to me in rebuke by an illustrious member of this forum), since this was completely solved by Korff a half century ago.

Perhaps it's time for variable grille slats that close when not needed, as seen on this Stutz.


Stutz by Tyler Linner [Ft. Corporate Insect Masters], on Flickr

[Big Dave]

There are some realities that intrude on aero design.

The human body has a finite number of positions you can bend it into and expect it to tolerate.

Mechanical components need space and only come in a limited number of arrangements.

Auto fashion is for ridiculously large-diameter wheels set at the corners.

Unibody design imposes its own set of limitations.

You probably have hit the limits.