German experimentation with low Cd automobiles in the 1930's
 

In the mid to late 30's in Germany, there was a lot of work done in creating vehicles with a low Cd. The impetous for this was the building of the Autobahn, which provided a roadway that was capable of handling much higher speeds than the typical car/engine combinations available at the time could produce. They soon found that by reducing a car's drag, the existing engines could propel a car much faster down the Autobahn than it could could do in a traditionally shaped car body. Unfortunately this bout of automotive experimentation was shut down with the the start of WWII and most of the vehicles lost in the ensuing conflict. The following website (in Germen) shows a number of these cars (hit the "Tour" buttom at the bottom of each page to go to the next page). Its interesting to look at the state of the art back in the 1930's. There were some fairly wild looking designs.

http://www.design-classic-cars.de/jaray/kamm.html


1939 Maybach Stromlinienkarosserie
http://img.photobucket.com/albums/v4...sw38-ds-01.jpg

http://img.photobucket.com/albums/v4.../sw38-ds04.jpg

It's sad that we have gone so far backwards since then! That car would have a drag coefficient very similar to yours if it had front skirts and a belly pan.

It did have a belly pan (note the radiator air exhaust openings just in front of the door).

Nice find, basjoos.

Note that you can use a service like Google to get an imperfect English translation of the text.

Try this link

My favourite:



http://www.design-classic-cars.de/w28/old-van.jpg

Check out the sink with hot and cold running water. Perfect for cleaning up after fueling.:p

http://www.design-classic-cars.de/jaray/h-930-4s.jpg

MetroMPG -

Oh yeah, that's my favorite too! Looks like it has a center mount for the driver :

Attachment 49

If only the VW Beetle had been offered in this design style. I would have called it the "pill-bug" :

Attachment 50

CarloSW2

That "pillbug" was a 7-passenger car with a single driver's seat in front between the front wheel wells followed by 2 rows of 3-abreast seating with an air-cooled in-line 4 engine in the back. It was a research vehicle built on the frame of a Mercedes-Benz 170H W28 by Professor Schlör at the Technical university of Gottingen in 1937 and was lost during WWII. But it looks like the guys at that website are working on building a reproduction of it on a MB 170 frame that they have.

Another website with pics of German streamlined cars:
http://home.claranet.de/fachreporte/stromlinie.htm

On those sites they mentioned the book: Stromlinienautos in Deutschland by Ralf J.F.Kieselbach. Sounds like an interesting read.

German experimentation
 

Germany lost WW-I because of a shortage of fuel and rubber.Ultimately,Germany would also loose WW-II because of a shortage of fuel and rubber.In light of the glowing predictions of I.G.Farbenindustrie A.G.'s ability to produce synthetic fuel and rubber from Ruhr Valley coal,some who saw through the scam may have felt a technological imperative to allow the Fatherland to stretch out its limited resources in times of questionable bounty.Rommel weeped for the lack of gasoline which caused his defeat in North Africa and the end of his march towards the Suez,Persian Gulf,and Caspian Sea.The same streamlining may give us a little wiggle room as we negotiate $126/barrel oil.

What a fantastic article !
Thank you for posting this !

Very handsome cars.

Where can I find the .Cd of some of the cars in the article ? Does it say anything in the article about the .Cds of the cars ?

I only saw one .Cd figure.

I just glanced through that website real quickly just now. WOW!!!

Some of those vehicles were fantastic looking aesthetically and really seemed to be much more streamlined than some of today's rides....it's amazing to see where car design came from and where it is today.

The Sclor Pillbug car had a CD of 0.13, or about half of the best of today's production cars.

The process is simple: Using inverse methods, start with lofting lines the air is happy to follow, then work inward to design the vehicle accordingly.

Here's a good picture of the Pillbug:

http://www.spiegel.de/img/0,1020,1408871,00.jpg
http://img.photobucket.com/albums/v7...rd/pillbug.jpg

Hi,

Here's a front view of the Maybach:

http://images.google.com/url?source=...k0iApDwNHzy6vA

NeilBlanchard -

I think the Pillbug would make a great Aptera family-sedan model.

CarloSW2

Hello,

Yes, an the Pillbug beats the Aptera 2e for Cd! 0.13 vs 0.15 It seats 7; not just 4! Wow, it is waaaay ahead of it's time!

It has awkward doors (for the driver in particular) and zero front crush zone.

basically carmakers are still shaving the corners of a box rather than looking for ways to attach wheels and seats to a drop shape.

Too bad we cannot get a custom body builder on this site.

I think a prototype "pillbug" could be built on a S-10 chassis, or a bigger one (SUV of the future?) on a pickup chassis.

Yeah, the driver would be moved back, but that is not the prmary thing.

From a manufacturer's standpoint the Carden drive is doable but rear engine layouts will not pass collision standards.

Too bad about all those Porsches...

The article link leads to a generic page for me -- there is no article there. Is it now broken?

Unfortunately, that very comprehensive series of web pages on German streamlined cars disappeared last spring or summer. It also had a large number of engineering drawings of Schlor's "pillbug" which are now gone.

idea
 

When I saw that I looked out my window an saw my 1968 Cuda and thought, now that is an idea I could implement with something that has the basic outline anyway. I do custom fabrication metal work anyway and I've been wanting to do something along those lines. I'm working on fairings for my Bonneville bike and this would help move me along anyway. That cuda with a 318 four barrel at highway cruse it achieves 27mpg. I'm sure with a solid underbelly pan, and wheel fairing, lexan for the back tail light area, etc, I can get it over 30+. I have some other modifications on the induction system that make it that efficient. All while still having it's 235hp on tap. I like the Honda! Great aerodynamic modifications.

It's a shame that even though carmakers are making retro designs, they aren't copying good aerodynamics from the past. I guess focus groups don't like aero

http://www.moparmax.com/features/200...uda/trep02.jpg

1969 Barracuda Blowfish - Bonneville Salt Flats - Hot Rod Magazine

::: MoparMax ::: 69 Barracuda Set to Go - 8/1/2006

http://www.moparmax.com/features/200...uda/trep03.jpg

One way you can determine your car's potential mileage increase via aerodynamic drag reduction is to notice what your mileage increase is when you are drafting another vehicle. Since when drafting, the only thing that has changed is the reduction in wind drag and its effect on lowering your engine's loading (rolling resistance and engine rpm's are unchanged), the mileage you get while drafting is the mileage you could get by lowering your car's Cd.

The Cd on my car is now so low that drafting results in little change to my car's mileage.

Beautiful vehicles! and blind manufacturers, for not reviving them... they would not be gasping for air now if they did.

BTW I am convinced basjoos worked on at least the Maybach in his previous birth...

Nice!
 

I don't remember seeing that Barracuda before, great design for Bonneville! What a great looking car to boot! Almost looks like a nose piece from a Super Bird from the era but it's not.
Lowering the car is a big help and the nose piece is really great. For my use a type of retractable head lamp assembly from a Corvet would be fairly easy to place for street. That picture is motivating. I took a picture of literally every car at Bonneville last year for the main purpose of Aerodynamics as applied to the individual cars characteristics. Implementation of those ideas takes time to do them well. Right now my 72 Dusters engine is done and ready for installation. It has the new fuel system developed and I'll be re-painting it anyway. So implementation of those modifications are prime. It already has a belly pan that helped strengthen the Uni body frame along with frame rail connectors. It is NOT aerodynamic and just adding the body pan made a very noticeable difference. Although the scoops are nice they are just more drag. (Below older photo, it wont have that type of flame job) A nose like the Cuda from the above may still look good. I'm hoping to pull the Bike trailer to Bonneville with the Duster. The Cuda is looking like a better candidate. Sounds like I better make up my mind pretty soon! Aerodynamics is really cool and I'm enjoying learning more about it and application to specific gains towards this subject matter of mileage and efficiency. We're building an 1/8 scale model of the Bike to place in a small wind tunnel we made. Hoping to find the best design for this bike. Thanks for the pix of the Cuda Hypermiler01!

Hi,

I have a copy of the Hucho book (from the MIT library -- my spouse is a librarian at Harvard, and she got it on inter library loan!), and I will be able to make a 3D model of the Schlör Pillbug!

http://img.photobucket.com/albums/v7...lorPillbug.jpg
http://img.photobucket.com/albums/v7...rd/pillbug.jpg

basjoos -

I never thought of this. This is good to know for strategic aero-testing.

CarloSW2

If you want to quantify the potential mileage improvement, you can mount an airspeed indicator pitot tube just ahead of the nose of your car to determine what airspeed your car is experiencing while drafting (you'd need to try it in several locations to get the average airspeed experienced by the front of your car). Then, for example, if the drafting airspeed is half your ground speed (assuming no winds), the mileage you get while drafting at that airspeed is the mileage you would get if you halved your Cd from its current value.

While German designers were looking at streamlining in the 1930's, so were manufacturers in other countries. Look at a Chrysler Airflow of the 1930's in the USA or the Rover Speed 6 in the UK for just two examples.

Just found this shot of the schlor car in the wind tunnel:

http://www.meinklassiker.com/image.p...ph_top&id=3841

And this one with a nice prop attached. Ohh the pain...

http://www.meinklassiker.com/image.p...ph_top&id=3845

That prop needs a kilt. :)

Unfortunately, the average armchair aerodynamicist would think that the prop were mounted on the leading edge of the car, and complain of visibility issues. :rolleyes:

Yeah, LOL.

Or some might think, OMG, it's early evidence of a perpetual motion car. Generator produces electricity as you drive. No wonder the car "disappeared" <knowing wink>

Those are totally awesome new pictures! How did you find them?

It had doors on both sides. Notice the tufts near the bottom behind the rear wheels -- they are blowing upward.

[Edit: This site has some (unsubstantiated) info:

Here's the lofting line drawing from Hucho:
http://img.photobucket.com/albums/v7...ingLines-1.png
This is close, but there are some inaccuracies: there is no pillar at the center of the windshield, and the dimension for the height should be just on the body (I think).

Has anyone ever considered making a car out of the fusilage of a small heli-chopper? (Or building the same from plans for a heli-chopper, which can be had much cheaper.)

I found another picture of the Schlörwagen "Pillbug" here:

http://img.photobucket.com/albums/v7...ideProfile.jpg

That site also has a better resolution picture with the propeller -- it had a fender bender:
http://res.magnus.de/res/_2/3/4/0/94059.jpg
See the missing paint and the bent 'A' pillar on the nearside front...
Also, the fresh air intake is open in this shot.

Another page (in German) that has some additional pictures!

http://www.meinklassiker.com/de/maga...ichte/2/1/2086

It loads very slowly...

http://img.photobucket.com/albums/v7...-FrontView.jpg

Score!

http://img.photobucket.com/albums/v7...r-Interior.jpg

Mega-Score!

100 Years - Untersuchungen an Autos und Gebäuden

Google for "Schlörwagen"
http://www.dlr.de/100Jahre/en/Portal...39_schloer.jpg
http://www.dlr.de/100Jahre/en/Portal..._propeller.jpg
http://www.dlr.de/100Jahre/en/Portal...tenansicht.jpg

That thing rules :thumbup: