Sub-Cd 0.09 paradigm

[aerohead]

Originally Posted by Frank Lee

Hell, we were all gonna have flying cars by 1965.

Got more views of that shape and car?

Sorry Frank,they just tease us with the single image.
I keep waiting for a look at Ford's 'UFO', of Cd 0.055 or so.Pat Nixon,at Texas Tech told me about it back in 1990.He didn't offer an image.'keep waiting I suppose.

[aerohead]

Originally Posted by freebeard

x2

Is that the front or back? Are those tufts with shadows or is the whole thing louvered?

mikeyjd -- It would depend on the frontal area and a myriad of details about the drivetrain and tires.

We're looking at the front and the whole thing is festooned with tufts.
In 1980,VW did the same thing for their VW 2000,starting with a low drag body (The Klemperer body,Cd 0.16) and after a cooling system and features,it came in around Cd 0.23 for a production vehicle.

It was the cover photo for Hucho's 1st English version text.

[aerohead]

Originally Posted by Xist

I did a Google image search, but most of the images were unrelated.

I've only seen it in Subaru's SAE Paper which they presented at the annual congress.

[aerohead]

Originally Posted by cptsideways

Not dissimilar to an upturned fast boat hull in some respects

Very much so!
Teitgens and Ripley used something very much like an inverted hull at Westinghouse to produce this self-powered passenger rail car of Cd 0.08 in 1932.

[freebeard]

Originally Posted by Hersbird

I love the idea of driverless cars. Also you could train them together at higher speeds and get even better mpg.

When every intersection is like a circle-8 race, you'll be glad you don't have a windshield.

[Baltothewolf]

It does make me wonder why they don't make trains more aerodynamic. People won't choose to ride on it because it looks 'ugly' and would save a grip of money.

[freebeard]

Can't sleep! Train will eat me!

OTOH Newer Talgo trains


I understand to long nose is for ...uh... penetrating tunnels.

[darcane]

Originally Posted by aerohead

It' raining today and I walked here without my briefcase,so no calculator.Sorry.
Here's a graph for a car of 22-sq-ft frontal area and 3,400-lbs curb weight.
Looking at the right hand side you'll find a line for Cd0.10 which is close,and you can compare the road load to that of another Cd.
If the BSFC is maintained through gear-matching,then the new fuel consumption will mirror the reduction in road load.
<snip>
Here is a road load curve for HONDA's Dream-2 solar racer,of Cd 0.10,a lightweight tandem,maybe 9-sq-ft frontal area (I'd have to look).
You can see that at 100-mph,it requires less than 6-kW to move it.That's a 300-mpg car!
<snip>

This touches on something that I've been wondering about for a while.

In an effort to reduce fuel consumption to meet CAFE standards, manufacturers have been trying to reduce drag by chipping away at Cd. But equally important is A (frontal area) and that has typically been increasing, year over year. The XL1, for example, has a great Cd, but the small frontal area plays every bit as much of a role in it's fuel efficiency.

I suspect this may be a trend that we will start seeing too, especially as the mpg targets get harder to meet.

[mikeyjd]

Originally Posted by aerohead

That's a 300-mpg car!

[spacemanspif]

Originally Posted by darcane

This touches on something that I've been wondering about for a while.

In an effort to reduce fuel consumption to meet CAFE standards, manufacturers have been trying to reduce drag by chipping away at Cd. But equally important is A (frontal area) and that has typically been increasing, year over year. The XL1, for example, has a great Cd, but the small frontal area plays every bit as much of a role in it's fuel efficiency.

I suspect this may be a trend that we will start seeing too, especially as the mpg targets get harder to meet.

Doubtful; look at the difference in size between an older Metro and a new Mirage. Car companies keep making taller and wider cars to add comfort and safety. Many people complain about how hard it is to get in and out of low cars, my older (in their 40s) friends used to complain constantly about getting in and out of my Saturn and now say "this car is so much easier to get in/out of than your old Saturn" about my Focus. Consumers want easy in/out and shoulder/head room so I only see cars getting bigger and bigger...