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

[NeilBlanchard]

Thanks - it's the Hip point?

I don't think the H-point could be a whole lot lower - the Trev is a battery powered vehicle and the floor is where the battery pack needs to be, for the lowest Cg possible. The top of the canopy (made by a sail plane builder - can you tell?) is probably just over 4' high - and its the apex on a very sleek dome. Improving the Cd by 0.01 would be much more meaningful.



That looks like a 14" Honda rim to me? If so, the tire would be about 2' and the apex of the canopy would be about 4'-3" above the ground.

Here's a photo with three people (one short, one average, one tall):


Here it is with some school age kids:




These people are bent over to look in, and they are still taller than the car:

[Sven7]

So you move the batteries a bit to get your butt lower! Get your butt lower, lower the roofline, reduce frontal area by 1/4 sq ft. Of course I was not involved in designing or building the car so I don't know the constraints. Playing armchair car designer is fun, though.

It could easily be a bit longer- as we know, length can be good for aero as well. They are Civic HX wheels, the same kind I'm buying for Ren.

[arcosine]

It needs front skirts.

[freebeard]

NeilBlanchard -- Those are great posts. I knew of both cars, but you've provided more on them than I'd seen elsewhere. Thanks. Any specs on the wheelbase, track, &etc.?

How does the Urbee's 3D printed body panels make you feel?

The Trev appears to have a canopy that both alligators from the rear bulkhead and hinges down the right side. Am I not getting something? Maybe the 'problem' isn't the H-point so much as those 14" wheels.

In General Efficiency I started a thread on recreating the Messerschmitt Kabinenroller. I pointed to the articles on Autospeed that were based on the Trev. I like Julian Edgars' writing. For reference they are
Issue: 543/Section: Technical Features /11 August, 2009/Cardboard Cars?
Issue: 516 /Section: DIY Tech Features/3 February, 2009/Building an Ultra Light-Weight Car, Part 1
Issue: 517/Section: DIY Tech Features/10 February, 2009/Building an Ultra Light-Weight Car, Part 2
Issue: 521/Section: Technical Features/10 March, 2009/Custom Bubble Canopies
But I encourage you to visit that thread.

Does anyone have a way to scrape all 50 pages into a .pdf file? More specifically, Has any one posted the VW Nils?

[NeilBlanchard]

The rear hinge is the earlier iteration. The current one is binged on the side - and it has a wiper that pivots at the leading edge of the canopy. I've inquired about dimensions and specs and 3D model, etc. They don't intend to produce it (they are volunteers at a university in Adelaide?)but they do have a couple of construction articles that I linked to on the Team Trev thread and they hope people will built it or vehicles like it.

I think it could be improved aerodynamically (in addition to skirting the front wheels): the sides need to slightly convex, and the shoulder needs to angle down rather than up.

[Sean T.]

Originally Posted by Sven7

They "disabled" the drivetrains. All I know is there is a bunch of charging paraphernalia in the trunk. Perhaps with a little messing around I could get a peek under the hood

I went and saw that car many times while I was in High School!

http://ecomodder.com/forum/showthrea...-56k-5598.html

I've also vacationed in Stillwater, MN oddly enough....... did you come all the way out here just for CCS?

[some_other_dave]

Originally Posted by NeilBlanchard

The Urbee has (at least) two very interesting features: rear wheel steering (hence no need to hinge the front wheel skirts)...

There's a reason that rear-wheel steering is pretty much unheard of in an automotive application. The handling would be diabolical...

-soD

[NeilBlanchard]

They may have come up with some geometry to account for this? I posted a link to a discussion on the Urbee thread.

[jtbo]

I wonder if this still classifies as a car, it has been converted for use on railway tracks, but just look at those aeromods of 1950's!
https://secure.flickr.com/photos/mrs...esclassiccars/

[arcosine]

Low rolling resistance too!