Interesting Aerodynamic Cars (Mike Vetter's ETV, also Avion)

[freebeard]

Open wheel or fendered?



I look at that and wonder if you could blow a bubble against an overhanging Superbeetle windshield and then trim it to fit like this. And how about that boat tail?

[The Toecutter]

Citroen SA103:


Not wanting to be outdone by Renault, Peugeot and Citroen began the ECO 2000 program. The 1981 Citroen SA103 was able to obtain 65 mpg, thanks to a 0.27 drag coefficient, 948 lb curb weight, and a rear-mounted 700cc 2-cylinder gasoline engine[1].

Citroen SA117:


The 1983 Citroen SA117 showed a remarkable improvement over its predecessor due to a drag coefficient of 0.21, front mounted engine with a front wheel drive configuration, and a curb weight of only 932 lbs; these improvements resulted in a fuel economy of 79 mpg[1]. The SL117 used the same engine as the SA103[1].

Citroen SA109:


The 1982 Citroen SA109 used an upgraded engine to 750cc 3-cylinder gasoline engine[1]. The car weighed in at 1,058 lbs and had a drag coefficient of 0.321, giving a fuel economy of 67 mpg[1].

Citroen SL110:


The 1984 Citroen SL110 was the first of the ECO 2000 vehicles revealed to the public[1]. It made use of the SA109's 35 horsepower engine, which allowed a top speed of 88 mph[2]. The fuel economy was 76 mpg combined, and 112 mpg at a steady 55 mph[2]. This was achievable due to a low drag coefficient of 0.22 and 992 lb curb weight[2].

Peugeot also revealed its ECO 2000 concept car. With a drag coefficient of 0.21, 990 lb curb weight, and a 28 horsepower 2-cylinder gasoline engine, the Peugeot ECO 2000 returned 70 mpg city and 77 mpg highway[3].

Peugeot VERA:


Peugeot VERA+:


An effort by Peugeot from 1982 were its VERA and VERA+ concept cars. Unlike the ECO 2000, these cars used 50 horsepower turbo diesel engines[3]. The VERA+ had a 0.22 drag coefficient, 1,740 lbs curb weight, and achieved 55 mpg city, 87 mpg highway[3]. The VERA+ also had performance comparable to the commercially available cars of its time, with 0-60 mph acceleration in 13.2 seconds and a top speed of 100 mph[4].

References:

[1] Histomobile. (2004, October 15). Citroen Eco 2000 concept. Retrieved June 27, 2007 from http://www.histomobile.com/1/Citroen...2000.htm?lan=1

[2] Generation Futures. (2006, March 26). Mon avis d'utilisateur sur la Citroën AX 14 TRD, ainsi que son coût kilométrique réel. Retrieved June 27, 2007 from 50 000 km avec une Citro?n Ax diesel, mon avis d'utilisateur ainsi que son co?t kilom?trique r?el.

[3] Bleviss, D. (1988). The New Oil Crisis and Fuel Economy Technologies. New York: Quorum Books

[4] Audi Sport Collection. (2007, June 29). Magazine : L'Audi 2000 face à ses rivales. Retrieved June 29, 2007 from http://www.audisportcollection.com/ASC2006/392.php

[The Toecutter]

I look at that and wonder what a single-seater car built with the form factor and low drag of a LeMans velomobile, with added wheel fairings, full suspension, maybe 5-6" ground clearance, with a 3T wind Leafbike hub motor in each front wheel and a HubMonster in the rear each run at 128V, a LoneStar battery pack rated to 200C discharge, and a PowerVelocity controller driving each wheel to make ~150 horsepower peak in total would be like. In a vehicle that could weigh under 200 lbs.

And that's what can be done with stuff readily available off the shelf. The hub motor tech that's been shelved by companies like AMZ offers the possibility of 50 horsepower peak in a 7 lb motor, which in turn would allow a 150 lb vehicle to make ~150 horsepower.

Originally Posted by freebeard

Open wheel or fendered?



I look at that and wonder if you could blow a bubble against an overhanging Superbeetle windshield and then trim it to fit like this. And how about that boat tail?

[freebeard]

I've lost the original refernece for that, but I believe it was Agusta, who made the scooter in the picture, in Spain in the 1960s that built it.

The only thing you left out is a Basalt fiber monocoque shell for the body.

Rossignol's Experience 86 Basalt ski blends a lightweight build with a smooth ride for carving across the entire mountain. A paulownia wood core reduces overall weight, while basalt layers absorb vibration for a smooth, quiet feel.
https://basalt.guru/

Those Citroen are amazing.

[aerohead]

Originally Posted by freebeard

Open wheel or fendered?



I look at that and wonder if you could blow a bubble against an overhanging Superbeetle windshield and then trim it to fit like this. And how about that boat tail?

It's kind of a hybrid.
Much of the wheel is shielded, however the outer face retains the gap mutilation and partial windage.
The rear suspension looks a bit like a torture chamber for the side flow, contaminating the onset flow to the tail.
Baron von Koenig-Fachsenfeld made his name, winning a race, by removing an impotent boat-tail like this from a Mercedes' racer. It was offering no drag reduction, only added mass, and aggravating the polar moment of inertia.
I suppose one could try
blowing the acrylic, but pros typically vacuum the heat-softened plastic into a break-away, perforated wooden tool of desired geometry. It's the only way to guarantee the optical purity of the screen.
It would never pass DOT requirements for a road car.
The tooling for a DOT laminated windshield for James Bedes' small 'jet motorcycle' was $ 10,000 in 1980 dollars.
'sucks to be poor!

[freebeard]

It would never pass DOT requirements for a road car.

I thought the separate panel in front is a glass windshield, while the rest is 'roof'. It look more viable than the bubbletops Barris, Cushenberry and Starbird made.

[aerohead]

Originally Posted by freebeard

I thought the separate panel in front is a glass windshield, while the rest is 'roof'. It look more viable than the bubbletops Barris, Cushenberry and Starbird made.

Okay. Sorry. Now I see what the initial intent was.
I'd still recommend sucking it into a mold. Without it, I don't see how you could have any control over the shape.
Even skylight blisters are clamped into a frame, exactly like what they'll ultimately be mounted to, when they're blown from below.
And they're 'inflation-valve' is only enabled by an infrared beam which is severed as the plastic reaches it's desire height.
I've been to George Barris's studio on a field trip to San Fernando. All his plex was tool-formed.

[Bicycle Bob]

I worked in a shop with occasional needs for large vacuum forming. Our oven was made from fireproof panels and light metal angles. It would take a 4 X 8 on edge. It was hung from I-beam drapery track so it could be wheeled right out on those little rollers. The heat came from a motley collection of electric elements on the bottom. The key to getting good parts instead of scrap was the addition of a blower, re-assembled with the fan inside and the motor outside to vigorously circulate the air.

[freebeard]

Uniform heating.

I think acceptable quality can be achieved. Couln't be worse than those mid/late-1950s compound curve windshields made the way aerohead describes.

How To Make Parabolic Mirrors From Space Blankets - NightHawkInLight

I've been looking, today, at the new Lexus RZ540e. It has an interesting design vocabulary.


http://www.wapcar.my/news/lexus-trad...be-rz450e-5018

The LF-30 concept

tarantas.news/posts/id13691-7dys4jnte3jbalq1oibf

That's an interesting use of a perforated mesh over two different air intakes, one vertical and one horizontal. This has the deepest pores I've seen since the Porsche 959:



What comes across on the production version is the strong taper of the front fender top and bottom, while the rear fender is bulging out at the middle. Look at the rear edge of the door cut line, and the strong chamfer on the nose. The concept has a blunt, narrow nose that stands proud of the windshield, with massive rectangular intakes.

[freebeard]

JACG: luxury overlander Land Rover Defender / Bowlus travel trailer by Duckworth Overland of Bristol

I'm skeptical. A Bowlus would have the door on the end, and the tailpiece would have little triangular windows.

Still. Nice radius/chamfer on the truncation.