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Quadcopters
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 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] |
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 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vortex Ring State
The vortex ring state (VRS) is a dangerous aerodynamic condition that may arise in helicopter flight, when a vortex ring system engulfs the rotor, causing severe loss of lift. The vortex ring state is sometimes referred to as settling with power. The Federal Aviation Administration (FAA) sees these terms as synonymous, whereas Transport Canada sees them as two different phenomena. A vortex ring state sets in when the airflow around a helicopter's main rotor assumes a rotationally symmetrical form over the tips of the blades, supported by a laminar flow over the blade tips, and a countering upflow of air outside and away from the rotor. In this condition, the rotor falls into a new topological state of the surrounding flow field, induced by its own downwash, and suddenly loses lift. Since vortex rings are surprisingly stable fluid dynamical phenomena (a form of topological soliton), the best way to recover from them is to laterally steer clear of them, in order to re-establish l ... [...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 Cheltenham (), also known as Cheltenham Spa, is a spa town and borough on the edge of the Cotswolds in the county of Gloucestershire, England. Cheltenham became known as a health and holiday spa town resort, following the discovery of mineral ... 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 Gloster Gladiator, Gladiator, the RAF's last biplane fighter. The company built most of the wartime production of Hawker Hurricanes and H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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 n landlords, graduated from the department of history and philology of the |
Louis Breguet
Louis Charles Breguet (2 January 1880 in Paris – 4 May 1955 in Saint-Germain-en-Laye, Île-de-France) was a French aircraft designer and builder, one of the early aviation pioneers. Biography Louis Charles Breguet was the grandson of Louis-Francois-Clement Breguet, and great-great-grandson of the famous horologist Abraham-Louis Breguet. In 1902 Louis married Nelly Girardet, the daughter of painter Eugène Girardet. They had five children together. In 1903, he graduated from École supérieure d'électricité, which was the top electrical engineering school in France. In 1905, with his brother Jacques, and under the guidance of Charles Richet, he began work on a gyroplane (the forerunner of the helicopter) with flexible wings. On 29 September 1907, at his workshop at La Brayelle, it achieved the first ascent of a vertical-flight aircraft with a pilot, albeit only to a height of . It was also not a free flight, as four men were used to steady the structure. He buil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodyne (aeronautics)
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons. The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called '' aeronautics.'' Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others. History Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
