German experimentation with low Cd automobiles in the 1930's

[cfg83]

Neil -

Originally Posted by NeilBlanchard

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



...

This is my favorite picture. I think it needs a caption :

Pilly, we need to talk ...

CarloSW2

[NeilBlanchard]

Finding these pictures is awesome -- I feel like I want to build one!

With articulated front wheel skirts, the width and stability could be addressed.

A modernized (read: safer and lighter weight structure) an EV version of this design would be a stunner. It could be made narrower and the front track could be widened. You would probably want to keep the proportions close, and the trailing edge behind the rear wheels, also probably some wheel strakes -- could make this design close to perfect.

For the aero geeks among us, check out the high resolution pictures of the wind tunnel(s) from the 1930's in Germany -- the link is above in post #39.

[MetroMPG]

That high res wind tunnel picture is great. Definitely some weird flow going on aft of the rear wheel.

[Jyden]

Great pictures, and a lovely car. Someone shold start make them in this shape. I would buy one

[basjoos]

I wonder if the Brits still have the Schlorwagen? The Oldtimer article said that they grabbed it at the end of WWII and took it to back to England. The article also mentioned that it was very sensitive to crosswinds, which would be expected with a heavy 4 cylinder motor in the rear end of the car and most of its side cross sectional profile positioned ahead of the motor. Remember what it was like driving the original VW Beetle in a strong crosswind. This would be less of a problem with today's lighter weight engines and even less of a problem with an EV version's distributed battery load.

From what some of the other articles mentioned, they were planning to put it into production, but the war intervened. I wonder how they were planning to acess the front wheels for service? The rear wheels have a skirt over them, but the front wheels are located inside fully enclosed wells inboard on the car.

That isn't a bent "A" pillar in the "propeller car" photo. They were apparently testing the drag penalty of various cabin air ventilation methods (more important in the days before A/C when you had to flow larger amounts of air through the cabin to keep the occupants comfortable). If you look at that photo of the interior, you can see an angled brace where the upper, inside corner of each corner windshield could open inward slightly for cooling in a similar, but reverse, fashion to the way the rear side windows on some of the early VW's used to open outward slightly to allow air to enter or exit.

[NeilBlanchard]

I think the bent 'A' pillar on the propeller version is related to the dent/missing paint patch on the front lower corner. Methinks it had a fender bender...

If it is in London -- or wherever, I hope that it is made public again!

I think I read that it was build using a Mercedes [170 H] chassis, and so the stability might also be based on the suspension of that day? In combination with the heavy engine in the rear? The Tatra could get out of hand because of this, apparently -- it has that fin on the spine, and the engine is an air-cooled aluminum V8. Which raises the question: how is the Schlörwagen cooled?

[orange4boy]

Mein Gott. Ausgezeichnet! Süpercool! So eine fantastiche machine!

[basjoos]

It was built on a Mercedes 170 H chassis, which was powered by a water cooled in-line 4. Don't know how Professor Schlor routed the cooling air flow to the radiator(s). There's no obvious air scoops like on the Tatra.

[NeilBlanchard]

Hi,

I'm finding some more information on the Schlörwagen; including that the Cd of a prototype was even lower: 0.113. The actual car might be 0.186, which is still excellent. Here's the Google translation of this page:

Here is the text of the press release:

Dr. Ing Karl Schlör in 1936 by Krauss-Maffei in Munich, to the Aerodynamic testing Institute Göttingen e. V. (AVA). This was the Kaiser-Wilhelm-Institut Göttingen under the supervision of Prof. Dr. Ludwig Prandtl (1875-1953) assumed.

There has already been by Dipl.-Ing. A. Lange on a stream-line model researched and drawn. This design was around the Jaray form with the rear of spillage, in an improved presentation. In the model, wind tunnel the Institute has been a fabulous CW-measured value of 0.14, but with coverage of all 4 wheels. At this time, without the project to an end have led to Ing A. Lange retired from his professional work out. Dr. Ing Karl Schlör took his place. With his collaborator Hans Becker did not want to continue the work of Ing Schlör Lange, but opted for a Einvolumen-body. The basic form showed a wing section.

Model wind-tunnel measurements were supposedly one of CW-value 0.113.

The leaders found this result so much that decided the car was built. As chassis was a modified Mercedes Chassis 170h read by Charles Schlör. The wind tunnel model was on IAA 1938 issued in Berlin. A year later, the visitors saw the finished vehicles, which in the meantime, at the Lewis brothers in Food was karossiert. The vehicle is brought in a wind tunnel of the AVA a CW-value of 0,186 - an absolute sensation.

What helped this was covered, enclosed ground and the windows which, with the Aluaußenhaut were flush. In spite of the aluminum body of the Car around 250 kg heavier than the standard sedan. Schlor the car, as he called from now on, with a wheelbase of 2.60 m, 4.33 m in length and a height of only 1.48 m at its highest point. In the latitude he suggested with 2.10 m probably all that time there was on the streets.

The top speed was in the series-Mercedes about 105 km / h, when Schlörwagen 134-136 km / h. When consumption was 10-12 liters per 100 km and only 8 liters in favor of the aerodynamic vehicle identified. After the tests were complete, the car was placed in a corner and placed a cloth over it, because the Motor Transport Research Institute wartime has been abandoned.

Schlör also had to complete his military service, but his professional skills accordingly. He was with his friend and Staff Hans Becker sent to Riga. When the Mercedes truck plant quartered been together through her propeller sled parts of prey - built. So once at the beginning of this action, a 5-cylinder M11 was Radial engine with a capacity of approximately 130 hp, a Russian construction claimed as booty part.

Suggest someone suggested, you could order the mothballed Schlör car assemble and test, deploy and perhaps even in Russia. And said done, the engine was transported by train to Göttingen. The Schlör entmottet car was the Mercedes engine and disassembled to the Russian engine propeller mounted at the rear. The results were excellent.

This test car was propeller driven by various debates not used in Russia, but arrived after the Finnish Rovaniemi - As a propeller-pressure test. How and when the car Schlör back came to Germany is not known.

After the war, Dr. Ing Karl Schlör went to the Bavarian State Ministry for Transport in Munich. Here he was responsible for the car Tire industry and imports of the Allies. The British occupiers had the Kaiser Wilhelm Institute, and thus the AVA dissolved. Today, the German Research Institute for Air-called Aerospace eV. Schlör The car was confiscated and never again issued.

Allegedly, he was brought to England. There, he may still stands today. After many projects on his own behalf and for the German automotive industry, Dr. Charles Schlör died in 1997.


MfG Jörg

[Jyden]

http://www.nast-sonderfahrzeuge.de/M...y.php?id=25943