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Anti-shock Body
Anti-shock body is the name given by Richard T. Whitcomb to a pod positioned on the upper surface of a wing. Its purpose is to reduce wave drag while travelling at transonic speeds ( Mach 0.8–1.0), which includes the typical cruising range of conventional jet airliners. 'The Cambridge Aerospace Dictionary' defines shock body (also known as Whitcomb body, Küchemann carrot or speed bump) as a streamlined volume added to improve area rule distribution. The anti-shock, or shock body, was one of a number of ways of implementing what was then the recently developed area rule. Another was fuselage shaping. Theory The theory behind the anti-shock body was independently developed during the early 1950s by two aerodynamists, Richard Whitcomb at NASA and Dietrich Küchemann at the British Royal Aircraft Establishment.Barnard and Philpott 2010, p. 254. The anti-shock body is closely associated with the area rule, a recent innovation of the era to minimise wave drag by having a cross-secti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard T
Richard is a male given name. It originates, via Old French, from Old Frankish and is a compound of the words descending from Proto-Germanic ''*rīk-'' 'ruler, leader, king' and ''*hardu-'' 'strong, brave, hardy', and it therefore means 'strong in rule'. Nicknames include " Richie", " Dick", " Dickon", " Dickie", "Rich", " Rick", "Rico", " Ricky", and more. Richard is a common English, German and French male name. It's also used in many more languages, particularly Germanic, such as Norwegian, Danish, Swedish, Icelandic, and Dutch, as well as other languages including Irish, Scottish, Welsh and Finnish. Richard is cognate with variants of the name in other European languages, such as the Swedish "Rickard", the Catalan "Ricard" and the Italian "Riccardo", among others (see comprehensive variant list below). People named Richard Multiple people with the same name * Richard Andersen (other) * Richard Anderson (other) * Richard Cartwright (disambiguati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave Drag
In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (resting) value at some frequency. When the entire waveform moves in one direction, it is said to be a ''traveling wave''; by contrast, a pair of superimposed periodic waves traveling in opposite directions makes a '' standing wave''. In a standing wave, the amplitude of vibration has nulls at some positions where the wave amplitude appears smaller or even zero. Waves are often described by a ''wave equation'' (standing wave field of two opposite waves) or a one-way wave equation for single wave propagation in a defined direction. Two types of waves are most commonly studied in classical physics. In a ''mechanical wave'', stress and strain fields oscillate about a mechanical equilibrium. A mechanical wave is a local deformation (strain) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transonic flow is seen at flight speeds close to the speed of sound (343 m/s at sea level), typically between Mach 0.8 and 1.2. The issue of transonic speed (or transonic region) first appeared during World War II. Pilots found as they approached the sound barrier the airflow caused aircraft to become unsteady. Experts found that shock waves can cause large-scale separation downstream, increasing drag and adding asymmetry and unsteadiness to the flow around the vehicle. Research has been done into weakening shock waves in transonic flight through the use of anti-shock bodies and supercritical airfoils. Most modern jet powered aircraft are engineered to operate at transonic air speeds. Transonic airspeeds see a rapid increase in drag fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach Number
Mach number (M or Ma) (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Moravian physicist and philosopher Ernst Mach. : \mathrm = \frac, where: : is the local Mach number, : is the local flow velocity with respect to the boundaries (either internal, such as an object immersed in the flow, or external, like a channel), and : is the speed of sound in the medium, which in air varies with the square root of the thermodynamic temperature. By definition, at Mach1, the local flow velocity is equal to the speed of sound. At Mach0.65, is 65% of the speed of sound (subsonic), and, at Mach1.35, is 35% faster than the speed of sound (supersonic). Pilots of high-altitude aerospace vehicles use flight Mach number to express a vehicle's true airspeed, but the flow field around a vehicle varies in three dimensions, with corresponding variations in local Mach number. The loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Airliner
A jet airliner or jetliner is an airliner powered by jet engines (passenger jet aircraft). Airliners usually have two or four jet engines; three-engined designs were popular in the 1970s but are less common today. Airliners are commonly classified as either the large wide-body aircraft, medium narrow-body aircraft and smaller regional jet. Most airliners today are powered by jet engines, because they are capable of safely operating at high speeds and generate sufficient thrust to power large-capacity aircraft. The first jetliners, introduced in the 1950s, used the simpler turbojet engine; these were quickly supplanted by designs using turbofans, which are quieter and more fuel-efficient. History Early history The first airliners with turbojet propulsion were experimental conversions of the Avro Lancastrian piston-engined airliner, which were flown with several types of early jet engine, including the de Havilland Ghost and the Rolls-Royce Nene. They retained the two inboa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Rule
The Whitcomb area rule, named after NACA engineer Richard Whitcomb and also called the transonic area rule, is a design procedure used to reduce an aircraft's drag at transonic speeds which occur between about Mach 0.75 and 1.2. For supersonic speeds a different procedure called the supersonic area rule, developed by NACA aerodynamicist Robert Jones, is used. Transonic is one of the most important speed ranges for commercial and military fixed-wing aircraft today, with transonic acceleration an important performance requirement for combat aircraft and which is improved by reductions in transonic drag. Description At high-subsonic flight speeds, the local speed of the airflow can reach the speed of sound where the flow accelerates around the aircraft body and wings. The speed at which this development occurs varies from aircraft to aircraft and is known as the critical Mach number. The resulting shock waves formed at these zones of sonic flow cause a sudden increase in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program, aeronautics research, and outer space, space research. NASA was National Aeronautics and Space Act, established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo program, Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion (spacecraft), Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew Program, Commercial Crew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dietrich Küchemann
Dietrich Küchemann CBE FRS FRAeS (11 September 1911 – 23 February 1976) was a German aerodynamicist who made several important contributions to the advancement of high-speed flight. He spent most of his career in the UK, where he is best known for his work on Concorde. Biography Küchemann was born in Göttingen where he studied at its University of Göttingen, home of the largest German institute of aerodynamics. He was originally going to move on to pure physics research under Max Born, a friend of his father's, but lost this chance when Born and several other Jewish members of the University staff were expelled from the country by the Nazi regime. Instead Küchemann went on to join Ludwig Prandtl in aerodynamics research. He published his doctoral thesis in 1936. With the war looming, Küchemann volunteered for service in 1938, and as expected was given a non-combatant role in Signals. He held the rank of Unteroffizier from 1942 to 1945, but he saw no active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Aircraft Establishment
The Royal Aircraft Establishment (RAE) was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence (MoD), before finally losing its identity in mergers with other institutions. The first site was at Farnborough Airfield ("RAE Farnborough") in Hampshire to which was added a second site RAE Bedford (Bedfordshire) in 1946. In 1988 it was renamed the Royal Aerospace Establishment (RAE) before merging with other research entities to become part of the new Defence Research Agency in 1991. History In 1904–1906 the Army Balloon Factory, which was part of the Army School of Ballooning, under the command of Colonel James Templer, relocated from Aldershot to the edge of Farnborough Common in order to have enough space to inflate the new "dirigible balloon" or airship which was then under construction.Walker, P; Early Aviation at Farnborough, Volume I: Balloons, Kites and Airships, Macdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross Section (geometry)
In geometry and science, a cross section is the non-empty intersection of a solid body in three-dimensional space with a plane, or the analog in higher-dimensional spaces. Cutting an object into slices creates many parallel cross-sections. The boundary of a cross-section in three-dimensional space that is parallel to two of the axes, that is, parallel to the plane determined by these axes, is sometimes referred to as a contour line; for example, if a plane cuts through mountains of a raised-relief map parallel to the ground, the result is a contour line in two-dimensional space showing points on the surface of the mountains of equal elevation. In technical drawing a cross-section, being a projection of an object onto a plane that intersects it, is a common tool used to depict the internal arrangement of a 3-dimensional object in two dimensions. It is traditionally crosshatched with the style of crosshatching often indicating the types of materials being used. With com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercritical Airfoil
A supercritical airfoil (supercritical aerofoil in British English) is an airfoil designed primarily to delay the onset of wave drag in the transonic speed range. Supercritical airfoils are characterized by their flattened upper surface, highly cambered ("downward-curved") aft section, and larger leading-edge radius compared with NACA 6-series laminar airfoil shapes. Standard wing shapes are designed to create lower pressure over the top of the wing. Both the thickness distribution and the camber of the wing determine how much the air accelerates around the wing. As the speed of the aircraft approaches the speed of sound, the air accelerating around the wing reaches Mach 1 and shockwaves begin to form. The formation of these shockwaves causes wave drag. Supercritical airfoils are designed to minimize this effect by flattening the upper surface of the wing. The origins of the supercritical airfoil can be traced back to the German aerodynamicist K. A. Kawalki, who designed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convair 990
The Convair 990 Coronado is an American narrow-body four-engined jet airliner produced between 1961 and 1963 by the Convair division of American company General Dynamics. It was a stretched version of its earlier Convair 880 produced in response to a request from American Airlines: the 990 was lengthened by , which increased the number of passengers from between 88 and 110 in the 880 to between 96 and 121. This was still fewer passengers than the contemporary Boeing 707 (110 to 189) or Douglas DC-8 (105 to 173), although the 990 was faster than either in cruise. Design and development American Airlines asked Convair to design an aircraft for coast-to-coast flights, able to fly nonstop from New York City to Los Angeles against the wind. They wanted a larger passenger capacity than the 880, which was the smallest of the first-generation U.S. jet airliners. It was known as the Convair 600 and was redesignated the Convair 990 in the month of its first flight. The 990 began fligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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