Paul Jaray (* 11. March 1889 in Vienna; " 22 September 1974 in pc. Gallen) was a Hungarian engineer and aerodynamicist. It applies beside Edmund Rumpler as a "father of the streamline form".
Jaray became at the 11. March 1889 as a fifth child of the Hungarian, Jewish buyer Adolf Jaray in Vienna born. It studied mechanical engineering in Vienna (starting from 1906) and Prague (starting from 1911) and came 1912 to Friedrichshafen, where it was active as a chief designer in the aircraft construction Friedrichshafen. Likewise 1912 married Paul Jaray Olga Jehle, with which he had three children. Starting from 1914 Jaray worked then at Zeppelin in the building of airships, where he was involved in the development of the types LZ 38 to LZ 126. With Zeppelin researched Jaray within the range aerodynamics, a topic, which him far for many decades busy. Its realizations affected not only aviation, but also the automotive manufacture and even the bicycle technology. Jaray converted 1917 to the catholicism. Starting from 1923 Jaray in Switzerland lived. First it operated a in wells, of where out it worked as an advisor for the British government for the topic of airships. Starting from 1925 it manufactured buildings of licenses of the radio receiver Alaphon, starting from 1932 own radios with the radio service and building of radios AG in Luzern. In the year 1941 Jaray of technical managers became with aircraft construction Farner AG in Grenchen, starting from 1944 worked it at G. Naef flight dynamic in Fischenthal. 1950 lived Jaray in Kempten (Switzerland) and married in second marriage Marguerite Leuenberger. Paul Jaray died on 22 September 1974 in pc. Gallen.
Paul Jaray was interested already early in aviation. It already announced a patent for an airplane to 1912 with cantilever wings on an invention, which it however not far pursued. With Zeppelin he built a wind tunnel for 1919 and examined the flow characteristics of the airships. The result of these research were the Zeppeline LZ 120 Bodensee and LZ 121 north star. These two were the first completely streamlined built airships and were considerably based on the realizations of Paul Jaray. With these Zeppelinen the carrying body was arranged as before cylindric.
1920 sketched Jaray a Trethebelrad - which J-wheel - with which it would apply its aerodynamic realizations to the building of bicycles. By the J-wheel 1922/1923 by the Hesperus works in Stuttgart approximately 2000 pieces were built, which enjoyed particularly in Holland of large popularity. After deadly accidents by material defects production was stopped 1923.
Jaray announced a patent for a streamlined automobile body on 8 September 1921 at the realm patent office in Berlin. Because of Patentstreitigkeiten to its request only 1926 as DRP 441618 one allowed:
The Jaray body arranged already the basic form of today's automobiles: The front is rounded off and the tail pointed approaching, so that the side view reminds of a falling drop. Like already the Rumpler drop car (cw-value 0.28!) Jarays was aerodynamically optimized form of their time ahead. With the public and the technical literature the vehicles with the unusual optics were scoffed. The then usual bodies stood with their senkrechten radiators and the wheels with their enormous fenders, lying outside, such as barn gates in the wind. Due to the rather small Geschwindikeiten the aerodynamic organization of the vehicles did not play a large role into the 1920ern.
The first vehicles after Jaray license were the Ley T-6 (prototype), the AUDI type K and the Dixi G7. The AUDI type K reached a speed of 95 km/h with standard body, with Jaray body already 130 km/h. With the Dixi G7 the streamline form increased the maximum speed from 80 km/h to 100 km/h.