Ornithopter
An ornithopter ( AltGr. Ὄρνιθος πτερόν, dtsch bird wings ) is produced by movement of the wing aircraft, the propulsion. It flies in flapping flight. A meaning of the ornithopter so far achieved only in the area of experimental and model flying. In the early days of manned aviation flight tests were conducted with this principle. However, these were unsuccessful.
History
About 500 years ago Leonardo da Vinci researched the flight, the birds. He drew the first surviving draft of an ornithopter. First successful ornithopter models demonstrated the Frenchman Gustave Trouvé in 1870 before the French Academy of Sciences. Other attempts have been known by his compatriots Alphonse Penaud, Hureau de Villeneuve, Victor Tatin. Around 1890, Lawrence Hargrave built several ornithopter models, powered by steam and compressed air. He combined small flapping wing with a larger rigid wings. The same principle pursued Otto Lilienthal after realization of gliding to further develop its flight performance. To this end, he tried a little carbonic acid motors. Very well known were also the built in the 1940s, free-flying bird models of the German biologist Erich von Holst
Delft University of Technology explored in the program DelFly small ornithopter with cameras.
The company Festo presented at the Hannover Messe 2011 with the SmartBird a flight mechanics of the herring gull adaptierendes free-flying model with a wingspan of two meters in front. 2013 followed the BionicOpter, one based on the flapping wings of the dragonfly development of an aircraft.
The end of 2013 presented mathematician at New York University before an ultralight model flying machine that mimics the movement of jellyfish, the first ornithopter, which does not require control and aerodynamic stabilization.
Aircraft and wing beat
An essential step on the way from bird flight flying machine, today's aircraft, was the intellectual and technical separation of the functions lift and drive the wing. This step is attributed to George Cayley. The exploration of buoyancy by Otto Lilienthal and others led first to motorless flight, the development of suitable drives initially to the propeller ( Wright brothers ). The third function of the bird's wing is taking over substantial part of the flight control, for which the technique is also independent modules or principles developed (gravity control, 3 - axis control ).
Action principle
To bring an ornithopter to fly, it is necessary to implement complex motion sequences. The active principle is a coupled shock, rotational and longitudinal movement. Lift and thrust generated by up-and the wings while ornithopter. In this case, the so-called hand area of the wings is of particular importance to: the hand regions are rotated off the tee with the front edge forward and downward, on impact shows the leading edge of arm upward. Thus, the hand area of the wing has a similar propeller function. The additional application of the wing on impact shortens the lever arm and also minimizes the overshoot of the trunk.
According to recent research is of great importance in addition to the active wing movement the elastic properties of the wing.