|
Tricopter
A multirotor or multicopter is a rotorcraft with more than two lift-generating rotors. An advantage of multirotor aircraft is the simpler rotor mechanics required for flight control. Unlike single- and double-rotor helicopters which use complex variable pitch rotors whose pitch varies as the blade rotates for flight stability and control, multirotors often use fixed- pitch blades; control of vehicle motion is achieved by varying the relative speed of each rotor to change the thrust and torque produced by each. Due to their ease of both construction and control, multirotor aircraft are frequently used in radio control aircraft and unmanned aerial vehicle (UAV) (drone) projects in which the names tricopter, quadcopter, hexacopter and octocopter are frequently used to refer to 3-, 4-, 6- and 8-rotor rotorcraft, respectively. There is also the X8 (also called ''octo-quad'') configuration that is similar to the quadracopter design, except that it has eight rotors; the lower of wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coaxial Rotors
A coaxial-rotor aircraft is an aircraft whose helicopter rotor, rotors are mounted one above the other on Concentric objects, concentric shafts, with the same axis of rotation, but turning in opposite directions (contra-rotating). This rotor configuration is a feature of helicopters produced by the Russian Kamov helicopter design bureau. History The idea of coaxial rotors originates with Mikhail Lomonosov. He had developed a small helicopter model with coaxial rotors in July 1754 and demonstrated it to the Russian Academy of Sciences. In 1859, the British Patent Office awarded the first helicopter patent to Henry Bright for his coaxial design. From this point, coaxial helicopters developed into fully operational machines as we know them today. Two pioneering helicopters, the Corradino D'Ascanio#Between the wars, Corradino D'Ascanio-built "D'AT3" of 1930, and the generally more successful French mid-1930s ''Gyroplane Laboratoire'', both used coaxial rotor systems for flight. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter
A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), 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 short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway. The Focke-Wulf Fw 61 was the first successful, practical, and fully controllable helicopter in 1936, while in 1942, the Sikorsky R-4 became the first helicopter to reach full-scale mass production, production. Starting in 1939 and through 1943, Igor Sikorsky worked on the development of the Vought-Sikorsky VS-300, VS-300, which over four iterations, became the basis for modern helicopters with a single main rotor and a single tail rotor. Although most earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volocopter
Volocopter GmbH (formerly called E-Volo GmbH) is a German aircraft manufacturer based in Bruchsal (near Karlsruhe) and founded by Alexander Zosel and Stephan Wolf. The company specializes in the design of Electric aircraft, electric multirotor helicopters in the form of personal air vehicles, designed for air taxi use.Tacke, Willi; Marino Boric; et al: ''World Directory of Light Aviation 2015-16'', page 206. Flying Pages Europe SARL, 2015. The CEO is Dirk Hoke and chairman Stefan Klocke. History The company flew the Volocopter VC1 and Volocopter VC2 technology demonstrators, followed by the two-seat Volocopter VC200 prototype. The VC1 was first flown on 21 October 2011. The two-seat project that became the Volocopter 2X started in 2013, evolved from early single-seat Volocopter VC2 prototype flown in 2011. The two seat prototype was designated as the VC-200 and the derived production model the 2X. An on-line fundraising effort in 2013 on the ''Seedmatch'' website raised Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cierva Air Horse
The Cierva W.11 Air Horse was a helicopter developed by the Cierva Autogiro Company in the United Kingdom during the mid-1940s. The largest helicopter in the world at the time of its debut, the Air Horse was unusual for using three rotors mounted on outriggers, and driven by a single engine mounted inside the fuselage. Only two aircraft were built, further development by Cierva was stopped after the crash of the first one and little work was done under Saunders Roe before the project was ended and the second aircraft was scrapped in 1951. Development The W.11 "Air Horse" heavy lift helicopter was developed by the G & J Weir, Ltd., Aircraft Department, reconstituted in 1943 as the Cierva Autogiro Company. The "W" in the designation is a continuation of the autogiro and helicopter series developed by G & J Weir, Ltd., during the period 1932–1940. The W.11 was a development of the Weir W.6 dual transverse rotor helicopter. It is the only helicopter of its type ever built and ... [...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 fly successfully, 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, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse Rotors
A transverse-rotor aircraft is an aircraft with two large Horizontal plane, horizontal helicopter rotor, rotor assemblies mounted side by side. Single-rotor helicopters (unicopters) need an additional tail rotor or NOTAR, tail exhaust to neutralize the reaction (physics), reactional angular momentum produced by the main rotor. Transverse rotor helicopters, however, use counter-rotating rotors, with each cancelling out the other's torque. Counter-rotating rotor blades also won't collide with and destroy each other if they flex into the other rotor's pathway. In addition, transverse rotor configuration has the advantage of higher payload with shorter airfoil, blades, since there are two sets working to provide lift (force), lift. Also, all of the power from the engines can be used for lift, whereas a single-rotor helicopter must divert part of its engine power to generate tail thrust. Transverse rotor design with rotatable nacelles are known as tiltrotors while designs where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tandem Rotors
A tandem-rotor aircraft is an aircraft with two large helicopter rotor assemblies mounted one in front of the other in the horizontal plane. This configuration is mainly used for large cargo helicopters. Such aircraft are often informally referred to as "Chinooks," after the CH-47 Chinook, one of the first widely adopted heavy-lift helicopters with a tandem-rotor configuration. Design Single-rotor helicopters need a mechanism to neutralize the yawing movement produced by the single large rotor. This is commonly accomplished by a tail rotor, coaxial rotors, and the NOTAR systems. Tandem-rotor helicopters, however, use counter-rotating rotors, with each cancelling out the other's torque. Therefore, all of the power from the engines can be used for lift, whereas a single-rotor helicopter uses some of the engine power to counter the torque. An alternative is to mount two rotors in a coaxial configuration. The first successful tandem-rotor helicopter was built by Nicolas Flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail Rotor
The tail rotor is a smaller rotor mounted vertically or near-vertically at the tail of a traditional single-rotor helicopter, where it rotates to generate a propeller-like horizontal thrust in the same direction as the main rotor's rotation. The tail rotor's position and distance from the helicopter's center of mass allow it to develop enough thrust leverage to counter the reactional torque exerted on the fuselage by the spinning of the main rotor. Without the tail rotor or other anti-torque mechanisms (e.g. NOTAR), the helicopter would be constantly spinning in the opposite direction of the main rotor when flying. Tail rotors are simpler than main rotors since they require only collective changes in pitch to vary thrust. The pitch of the tail rotor blades is adjustable by the pilot via the anti-torque pedals, which also provide directional control by allowing the pilot to rotate the helicopter around its vertical axis. Its drive system consists of a shaft powered from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermeshing Rotors
An intermeshing-rotor helicopter (or synchropter) is a helicopter with a set of two main rotors turning in opposite directions, with each rotor mast mounted with a slight angle to the other, in a transversely symmetrical manner, so that the blades intermesh without colliding. The arrangement allows the helicopter to function without a tail rotor, which saves power. However, neither rotor lifts directly vertically, which reduces efficiency per each rotor. Yaw is accomplished through varying torque, which is done by increasing collective pitch on one of the blade sets. Most intermeshing designs have two blades per mast, although exceptions such as the Kellett XR-10 with three blades per mast do exist. The arrangement was developed in Germany by Anton Flettner for a small anti-submarine warfare helicopter, the Flettner Fl 265 as the pioneering example, and later the Flettner Fl 282 Kolibri. During the Cold War the American Kaman Aircraft company produced the HH-43 Huskie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclorotor
A cyclorotor, cycloidal rotor, cycloidal propeller or cyclogiro, is a fluid propulsion device that converts shaft power into the acceleration of a fluid using a rotating axis perpendicular to the direction of fluid motion. It uses several blades with a spanwise axis parallel to the axis of rotation and perpendicular to the direction of fluid motion. These blades are cyclically pitched twice per revolution to produce force (thrust or lift) in any direction normal to the axis of rotation. Cyclorotors are used for propulsion, lift, and control on air and water vehicles. An aircraft using cyclorotors as the primary source of lift, propulsion, and control is known as a cyclogyro or cyclocopter. A unique aspect is that it can change the magnitude and direction of thrust without the need of tilting any aircraft structures. The patented application, used on ships with particular actuation mechanisms both mechanical or hydraulic, is a Voith Schneider Propeller. Operating principle The b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
