Wunibald Kamm

Wunibald Kamm (April 26 1893 in Basel – October 11 1966 in Stuttgart) was an automobile designer, engineer, and aerodynamicist (aerodynamics). He is best known for his breakthrough in reducing car turbulence at high speeds; the style of car bodywork based on his research has come to be known as a Kammback or a Kamm-tail.

Design

The goal of automotive aerodynamics is to reduce the turbulence, or drag, caused by the shape of the automobile. Drag begins to increase after the rear of a car's cross-sectional area is reduced to fifty percent of the car's maximum cross section. On the other hand, a design with less drag (or air turbulence) means less resistance to forward motion, thus higher efficiency and an increased maximum velocity of the vehicle given the same powertrain.

Career

German Professor, Wunibald Kamm worked with aerodynamics engineer Baron Reinhard von Koenig-Fachsenfeld. They developed a design with a smooth roofline and a taper in the automobile's body that is suddenly chopped off at the rear end. This design makes the air flow act as if a full tapered "tail" was present on the vehicle. A full size prototype was developed in 1938. It was a four-door sedan featuring a sharply truncated rear end. The test car represented a compromise between a low air resistance and practicality in the automobile's size and shape.

The first "Kamm coupe"

In late summer of 1938, BMW tested a prototype of the so-called "Kamm-Coupe" based on their 328 chassis. It had a drag coefficient of only 0.25 compared to the great 1940 Mille Miglia winning BMW 328 Touring Coupe with drag coefficient 0.35. [ [http://www.cardesignnews.com/news/2004/041203mcd-history3/ Ihrig, Ron "Part 3: Production, Physics, Politics - Only the Strong Survive" German Design History in Car Design News, Dec 3, 2004] , retrieved on September 6 2007.] This automaker's naming of its coupé model appears to be the earliest use of "Kamm" to publicly describe an automobile body incorporating the Koenig-Fachsenfeld's design patent.

Kammback named production cars (USA)

*AMC Gremlin and AMC Eagle -- The design was not to improve streamlining, but to improve space efficiency.
*Chevrolet Vega -- The station wagon model had more taper than the Gremlin, but not enough to gain aero-effects.

The Kammback "cut off tail" design continues to be popular. Most often, however, it only insinuates streamlining when used in production cars. It is then only a design trick to make the vehicle look "fast".

Dr. Kamm's wind cheating principle is used in a variety of popular mass-market vehicles, supercars, highly efficient hybrid powered cars, as well as outright racecars.

Notes

External links

* [http://homepage.mac.com/christopher.z/hobby/80-AMXitems/Information/production/KammbackStory.html Article on the origins of Kammback design]
* [http://www.design-classic-cars.de/jaray/kamm.html Web pages (in German) with Kamm's designs and test cars]

Persondata
NAME = Kamm, Wunibald
ALTERNATIVE NAMES =
SHORT DESCRIPTION = automobile designer, engineer, aerodynamicist
DATE OF BIRTH = April 26 1893
PLACE OF BIRTH = Basel Switzerland
DATE OF DEATH = October 11 1966
PLACE OF DEATH = Stuttgart Germany