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Quadrotor
A quadcopter or quadrotor is a type of helicopter with four rotors. Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the modern UAV or drone. The small size and low inertia of drones allows use of a particularly simple flight control system, which has greatly increased the practicality of the small quadrotor in this application. Design principles Each rotor produces both lift and torque about its center of rotation, as well as drag opposite to the vehicle's direction of flight. Quadcopters generally have two rotors spinning clockwise (CW) and two counterclockwise (CCW). Flight control is provided by independent variation of the speed and hence lift and torque of each rotor. Pitch and roll are controlled by varying the net centre of thrust, with yaw controlled by varying the net torque. Unlike conventional helicopters, quadcopters do not usually have cyclic pitch control, in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadcopter Camera Drone In Flight
A quadcopter or quadrotor is a type of helicopter with four Helicopter rotor, rotors. Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity until the arrival of the modern UAV or drone. The small size and low inertia of drones allows use of a particularly simple flight control system, which has greatly increased the practicality of the small quadrotor in this application. Design principles Each rotor produces both lift (force), lift and torque about its center of rotation, as well as drag force, drag opposite to the vehicle's direction of flight. Quadcopters generally have two rotors spinning clockwise (CW) and two counterclockwise (CCW). Flight control is provided by independent variation of the speed and hence lift and torque of each rotor. Pitch and roll are controlled by varying the net centre of thrust, with yaw controlled by varying the net torque. Unlike conventional helicopters, quadcopters do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of STOL (Short TakeOff and Landing) or STOVL (Short TakeOff and Vertical Landing) aircraft cannot perform without a runway. In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production.Munson 1968.Hirschberg, Michael J. and David K. Dailey"Sikorsky". ''US and Russian Helicopter Development in the 20th Century'', American Helicopter Society, International. 7 July 2000. Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter, not to be confused with the single-blade monocopter) has become the most comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George De Bothezat
George de Bothezat ( ro, Gheorghe Botezatu, italic=yes, russian: Георгий Александрович Ботезат, italic=yes, June 7, 1882 – February 1, 1940) was a Romanian-Russian American engineer, businessman, and pioneer of helicopter flight. Biography George de Bothezat was born in 1882 in Saint Petersburg, Russian Empire, to Alexander Botezat and Nadine Rabutowskaja.Gheorghe Botezatu at The National Library of Moldova His father Alexander Il'ich Botezat belonged to a family of Bessarabian landlords, graduated from the department of history and philology of the |
De Bothezat Helicopter
The de Bothezat helicopter, also known as the Jerome-de Bothezat Flying Octopus, was an experimental quadrotor helicopter built for the United States Army Air Service by George de Bothezat in the early 1920s, and was said at the time to be the first successful helicopter. Although its four massive six-bladed rotors allowed the craft to successfully fly, it suffered from complexity, control difficulties, and high pilot workload, and was reportedly only capable of forward flight in a favorable wind. The Army canceled the program in 1924, and the aircraft was scrapped. Development and testing Self-described as "the world's greatest scientist and outstanding mathematician",Young 1982, p. 36. and having written one of the first scientific papers on the aerodynamics of rotary-wing flight, George de Bothezat was a refugee from the Russian Empire who had fled to the United States in the wake of the Russian Revolution. Having written and lectured extensively on rotorcraft theory, de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curtiss-Wright VZ-7
The Curtiss-Wright VZ-7 (also known as the VZ-7AP) was a VTOL quadrotor helicopter aircraft designed by the Curtiss-Wright company for the US Army. Like the Chrysler VZ-6 and the VZ-8 Airgeep it was to be a "flying jeep". Design and development The Aerophysics Development Corporation, a subsidiary of Curtiss-Wright, designed an "Aerial Platform" for a US Army Transport and Research Command "Flying Jeep" design competition. The Aerophysics design sat two in tandem between four ducted fan rotors and could also be armed with machine-guns or recoil-less rifles. To prove the design concept the US Army ordered two prototypes of a smaller single-seat demonstrator, the VZ-7, which were delivered to the US Army in mid-1958. The VZ-7 had a fuselage with the pilot's seat, fuel tanks and flight controls. On both sides of the fuselage the four propeller/rotors were attached, unshrouded (the aircraft did originally have shrouds, but these were later removed). The VZ-7 was controlled by chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Rotor
A helicopter main rotor or rotor system is the combination of several rotary wings (rotor blades) with a control system, that generates the aerodynamic lift force that supports the weight of the helicopter, and the thrust that counteracts aerodynamic drag in forward flight. Each main rotor is mounted on a vertical mast over the top of the helicopter, as opposed to a helicopter tail rotor, which connects through a combination of drive shaft(s) and gearboxes along the tail boom. The blade pitch is typically controlled by the pilot using the helicopter flight controls. Helicopters are one example of rotary-wing aircraft (rotorcraft). The name is derived from the Greek words ''helix'', helik-, meaning spiral; and ''pteron'' meaning wing. Design principles Overview The helicopter rotor is powered by the engine, through the transmission, to the rotating mast. The mast is a cylindrical metal shaft that extends upward from—and is driven by—the transmission. At the top of the mast i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertia
Inertia is the idea that an object will continue its current motion until some force causes its speed or direction to change. The term is properly understood as shorthand for "the principle of inertia" as described by Newton in his first law of motion. After some other definitions, Newton states in his first law of motion: The word "perseveres" is a direct translation from Newton's Latin. Other, less forceful terms such as "to continue" or "to remain" are commonly found in modern textbooks. The modern use follows from some changes in Newton's original mechanics (as stated in the ''Principia'') made by Euler, d'Alembert, and other Cartesians. The term inertia comes from the Latin word ''iners'', meaning idle, sluggish. The term inertia may also refer to the resistance of any physical object to a change in its velocity. This includes changes to the object's speed or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloster Aircraft Company
The Gloster Aircraft Company was a British aircraft manufacturer from 1917 to 1963. Founded as the Gloucestershire Aircraft Company Limited during the First World War, with the aircraft construction activities of H H Martyn & Co Ltd of Cheltenham, England it produced fighters during the war. It was renamed later as foreigners found 'Gloucestershire' difficult to pronounce. It later became part of the Hawker Siddeley group and the Gloster name disappeared in 1963. Gloster designed and built several fighters that equipped the British Royal Air Force (RAF) during the interwar years including the Gladiator, the RAF's last biplane fighter. The company built most of the wartime production of Hawker Hurricanes and Hawker Typhoons for their parent company Hawker Siddeley while its design office was working on the first British jet aircraft, the E.28/39 experimental aircraft. This was followed by the Meteor, the RAF's first jet-powered fighter and the only Allied jet fighter to be put ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convertiplane
A convertiplane is defined by the Fédération Aéronautique Internationale (FAI or World Air Sports Federation) as an aircraft which uses rotor power for vertical takeoff and landing (VTOL) and converts to fixed-wing lift in normal flight. In the US it is further classified as a sub-type of powered lift. In popular usage it sometimes includes any aircraft that converts in flight to change its method of obtaining lift. Types of convertiplane Most convertiplanes are of the proprotor type, in which the same spinning blades are used as rotor blades for vertical flight and then pivot forward to act as propeller blades in horizontal flight. Proprotor types may be of either tilt rotor or tilt wing configuration. Tiltwing mechanisms tends to be more complicated. As with the helicopter, an engine failure could be disastrous even in the case of a cross-coupled twin rotor configuration. The stopped rotor type has a separate system for forward thrust. It takes off like a helicopter but for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
