random aero factoid
 

The 1924 Rumpler Sedan,without it's wheels,has the exact,same coefficient of aerodynamic drag as the 1938 AVA G'o'ttingen Schl'o'rwagen
http://i1271.photobucket.com/albums/...itled16_13.jpg
http://i1271.photobucket.com/albums/...ntitled1_9.jpg
Cd 0.186.

The schlor's steeper departure vs the rumpler's more template-like slope.
One seems better and pretty, but show me the money!

No wheels?

Is it a hovercraft now?

A jedi flamingo?
The aerodynamic force is strong with this one...

Thanks for posting that AeroHead.
I like the Rumpler as a good example of what you can do with an upright windshield.
With a plan taper, you can still get a good Cd.
I was thinking the other day of how that a Hummer could be redesigned to appear recognizable as a Hummer with its' trademark upright windshield, yet have excellent aerodynamics.
I did a sketch of what I had in mind and despite having a recognizable form, I think it could still be quite aerodynamic.

Phil, you are quite a good artist. If you feel up to it, would you consider sketching out a design like that yourself ?

I wonder how they compare in crosswind performance, as well as lift.

Unless the body proportion is twice as wide as it is tall, a vertical trailing edge is the natural result. Minimizing or eliminating the taper in elevation reclaims interior volume.

http://www.bgwspectre.com/customer/van1.png
http://www.bgwspectre.com/customer1.html

Hummer isn't the only flat-windshield body.

Most of the van conversions that rely on Type II sheet metal are too wide in the back. This fiberglass clip has, as I calculate, a perfect extension of the body contour. It could be further optimized—fender skirts ... hitch mounted perforated base plate ... plasma trip strips ....

The guy that runs BGW knows that it gets better gas mileage but he doesn't know how much. aerohead, what would your calibrated eyeball say is the Cd? About 0.30? That would translate to 5% gas mileage.

Replace the stock hatch (which really restricts engine access, needs an electric conversion) with V-shaped side-hinged double doors. And the air intake vents with an intake in a V-shaped ducktail spoiler. Boom, instant full boat tail — [Edit:0.25].

1921 Rumpler
 

Here is the 1921 Rumpler open sedan,Cd 0.54.While adding frontal area,the addition of the 1924 roof nearly cuts the Cd in half.
http://i1271.photobucket.com/albums/...d2/scan1_2.jpg
The car is definitely airfoil-shaped in plan-view.And the panoramic tug-boat windshield with generous header radius, makes for nice penetration without separation.

Hummer h-1
 

Seems like the Cd 0.70 H-1 could easily go to Cd 0.35 with edge rounding,gap closures and subtle shape optimization.Especially the military 'fastback' version.
I've streamlined them in my mind,but a rendering I've never done,and my plates pretty full for the next year ahead.
The Chevy Colorado was around Cd 0.40 and shared the same chassis as the Cd 0.51 HUMMER H-3,so we know there's some fruit hanging on those HUMMER trees.
But (horrible English!) the demographic who's purchased a Hummer probably would consider a streamlined version of any kind,an abomination and recoil in horror from it as bad as the men folk of 'The Simpson's' Springfield,when a Prius came down Main Street,and guys dove into the bushes to shield themselves from what would certainly rob their manhood if they were to look at it directly.:p