Introduction
Aurel Perșu (26 December 1890 – 5 May 1977) was a Romanian engineer and pioneer car designer, the first to place the wheels inside the body of the car as part of his attempt to reach the perfect aerodynamic shape for automobiles. He came to the conclusion that the perfectly aerodynamic automobile must have the shape of a falling water drop.
Patented aerodynamic design
Perșu, a specialist in airplanes aerodynamics and dynamics, implemented his idea in 1922–1923 in Berlin, building an automobile with an incredibly low drag coefficient of 0.28 (same as a modern Porsche Carrera) or even 0.22 (still not reached by almost any modern production cars), depending on the source. This drag coefficient was far better that the 0.8–1.0 common with automobiles used at that time. This allowed for the fuel consumption to decrease 4–5 times in Perșu’s automobile. It was the first car to have the wheels inside its aerodynamic line, which we take for granted today. This was Perșu's main innovation compared to the 1921 Rumpler Tropfenwagen ("drop car") of Austrian engineer Edmund Rumpler. Considering the diminished distance between the rear wheels, he gave up the differential system for the transmission of the engine torque. This meant that the car could safely negotiate curves at up to 60 km/h. Perșu's design received German patent number 402683 in 1924 and US patent 1648505 in 1927.
Technical museum
The original automobile ran for 120,000 km. Aurel Perșu donated it fully functional in 1961 to the Dimitrie Leonida Technical Museum in Bucharest. It has since been on display at the Museum, but currently has the wrong wheels and is in rather poor shape.
Derivative car designs
The original design work of Aurel Perșu inspired future iconic American car designs:
- Aptera
- Dymaxion car – Buckminster Fuller