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Variable Camber Wing
Variable camber is a feature of some of aircraft wings that changes the camber (or curvature) of the main aerofoil during flight. In one system, the leading and/or trailing edge sections of the whole wing pivot to increase the effective camber of the wing. This may be used to increase the maximum lift coefficient in order to shorten the take-off run, or to enhance manoeuvrability in the air. An early example was flown on the Westland N.16 of 1917.Lukins, A.H.; ''The book of Westland aircraft'', Aircraft (Technical) Publications Ltd, (1943 or 1944). Although flaps on the trailing or leading edge of a wing do vary the overall camber and are sometimes described as camber–changing flaps, they do not vary the main lifting surface in the same way that a variable-camber wing does. Various other mechanisms have been tried. These include a device that controls the location and shape of the entire upper surface of the airfoil, a retractable bridge that connects two separate high aspec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-wing Aircraft
A fixed-wing aircraft is a heavier-than-air aircraft, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft (in which a rotor mounted on a spinning shaft generates lift), and ornithopters (in which the wings oscillate to generate lift). The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft, and airplanes that use wing morphing are all classified as fixed wing. Gliding fixed-wing aircraft, including free-flying gliders and tethered kites, can use moving air to gain altitude. Powered fixed-wing aircraft (airplanes) that gain forward thrust from an engine include powered paragliders, powered hang gliders and ground effect vehicles. Most fixed-wing aircraft are operated by a pilot, but some are unmanned or controlled remotely or are completely autonomous (no remote pilot). History Kites Kites were used approximately 2,800 years ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing
A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-drag ratio, which compares the benefit of lift with the air resistance of a given wing shape, as it flies. Aerodynamics is the study of wing performance in air. Equivalent Foil (fluid mechanics), foils that move through water are found on Hydrofoil, hydrofoil power vessels and Sailing hydrofoil, foiling sailboats that lift out of the water at speed and on submarines that use diving planes to point the boat upwards or downwards, while running submerged. Hydrodynamics is the study of foil performance in water. Etymology and usage The word "wing" from the Old Norse ''vængr'' for many centuries referred mainly to the foremost limb (anatomy), limbs of birds (in addition to the architectural aisle). But in recent centuries the word's meaning ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camber (aerodynamics)
In aeronautics and aeronautical engineering, camber is the asymmetry between the two acting surfaces of an airfoil, with the top surface of a wing (or correspondingly the front surface of a propeller blade) commonly being more convex (positive camber). An airfoil that is not cambered is called a ''symmetric airfoil''. The benefits of cambering were discovered and first utilized by George Cayley in the early 19th century. Overview Camber is usually designed into an airfoil to raise its maximum lift coefficient CLmax. This minimizes the Stall (flight), stalling speed of aircraft using the airfoil. An aircraft with wings using a cambered airfoil will have a lower stalling speed than an aircraft with a similar wing loading and wings using a symmetric airfoil. One recent cambered design is called the supercritical airfoil. It is used for near-supersonic flight and produces a higher lift-to-drag ratio at near supersonic flight than traditional airfoils. Supercritical airfoils employ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerofoil
An airfoil (American English) or aerofoil (British English) is a streamlined body that is capable of generating significantly more lift than drag. Wings, sails and propeller blades are examples of airfoils. Foils of similar function designed with water as the working fluid are called hydrofoils. When oriented at a suitable angle, a solid body moving through a fluid deflects the oncoming fluid (for fixed-wing aircraft, a downward force), resulting in a force on the airfoil in the direction opposite to the deflection. This force is known as aerodynamic force and can be resolved into two components: lift (perpendicular to the remote freestream velocity) and drag ( parallel to the freestream velocity). The lift on an airfoil is primarily the result of its angle of attack. Most foil shapes require a positive angle of attack to generate lift, but cambered airfoils can generate lift at zero angle of attack. Airfoils can be designed for use at different speeds by modifying their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lift Coefficient
In fluid dynamics, the lift coefficient () is a dimensionless quantity that relates the lift generated by a lifting body to the fluid density around the body, the fluid velocity and an associated reference area. A lifting body is a foil or a complete foil-bearing body such as a fixed-wing aircraft. is a function of the angle of the body to the flow, its Reynolds number and its Mach number. The section lift coefficient refers to the dynamic lift characteristics of a two-dimensional foil section, with the reference area replaced by the foil chord. Abbott, Ira H., and Doenhoff, Albert E. von: ''Theory of Wing Sections''. Section 1.2 Definitions The lift coefficient ''C''L is defined by :C_\mathrm L \equiv \frac = = , where L\, is the lift force, S\, is the relevant surface area and q\, is the fluid dynamic pressure, in turn linked to the fluid density \rho\,, and to the flow speed u\,. The choice of the reference surface should be specified since it is arbitrary. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westland N
Westland or Westlands may refer to: Places *Westlands, Nairobi, an affluent neighbourhood in the city of Nairobi, Kenya * Westlands, Staffordshire, a suburban area and ward in Newcastle-under-Lyme *Westland, a peninsula of the Shetland Mainland near Vaila, Scotland Netherlands *Westland (municipality), Netherlands * Westland (region), Netherlands New Zealand *Westland District, a political subdivision on the West Coast of New Zealand's South Island *Westland Tai Poutini National Park, a national park **Informally, the name often used for the entire West Coast region, of which the Westland District is a part ** Westland (New Zealand electorate) a former parliamentary electorate in the above area **Westland Province, a province of New Zealand from 1873–76 United States * Westland, Indiana *Westland, Michigan * Westland, Oregon; see McKay Reservoir * Westland, Pennsylvania * Westland, Virginia *Westland Mall (Hialeah), a shopping mall in Hialeah, Florida *Westland Mansio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flap (aircraft)
A flap is a high-lift device used to reduce the stall (flight), stalling speed of an aircraft wing at a given weight. Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. Flaps are used to reduce the take-off distance and the landing distance. Flaps also cause an increase in Drag (physics), drag so they are retracted when not needed. The flaps installed on most aircraft are partial-span flaps; spanwise from near the wing root to the inboard end of the ailerons. When partial-span flaps are extended they alter the spanwise lift distribution on the wing by causing the inboard half of the wing to supply an increased proportion of the lift, and the outboard half to supply a reduced proportion of the lift. Reducing the proportion of the lift supplied by the outboard half of the wing is accompanied by a reduction in the angle of attack on the outboard half. This is beneficial because it increases the margin above the Stall (fluid dynamics), stall of the outbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable-sweep Wing
A variable-sweep wing, colloquially known as a "swing wing", is an airplane wing, or set of wings, that may be modified during flight, swept back and then returned to its previous straight position. Because it allows the aircraft's shape to be changed, it is a feature of a variable-geometry aircraft. A straight wing is most efficient for low-speed flight, but for an aircraft designed for transonic or supersonic flight it is essential that the wing be swept. Most aircraft that travel at those speeds usually have wings (either swept wing or delta wing) with a fixed sweep angle. These are simple and efficient wing designs for high speed flight, but there are performance tradeoffs. One is that the stalling speed is increased, necessitating long runways (unless complex high-lift wing devices are built in). Another is that the aircraft's fuel consumption during subsonic cruise is higher than that of an unswept wing. These tradeoffs are particularly acute for naval carrier-bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable-incidence Wing
A variable-incidence wing has an adjustable angle of incidence relative to its fuselage. This allows the wing to operate at a high angle of attack for take-off and landing while allowing the fuselage to remain close to horizontal. The pivot mechanism adds extra weight over a conventional wing and increases costs, but in some applications the benefits can outweigh the costs. Several examples have flown, with one, the F-8 Crusader carrier-borne jet fighter, entering production. History Some early aeroplanes had wings which could be varied in incidence for control and trim, in place of conventional elevator control surfaces. Wing warping varied the incidence of the outer wing and was used by several pioneers, including initially the Wright brothers. Early examples of rigid variable-incidence wings were not particularly successful. They include the Mulliner Knyplane in 1911, the Ratmanoff monoplane in 1913 and the Paul Schmidt biplane, also in 1913. A patent for a rigid variab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing X-53 Active Aeroelastic Wing
The X-53 Active Aeroelastic Wing (AAW) development program is a completed American research project that was undertaken jointly by the Air Force Research Laboratory (AFRL), Boeing Phantom Works and NASA's Dryden Flight Research Center, where the technology was flight tested on a modified McDonnell Douglas F/A-18 Hornet. Active Aeroelastic Wing Technology is a technology that integrates wing aerodynamics, controls, and structure to harness and control wing aeroelastic twist at high speeds and dynamic pressures. By using multiple leading and trailing edge controls like "aerodynamic tabs", subtle amounts of aeroelastic twist can be controlled to provide large amounts of wing control power, while minimizing maneuver air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. This program was the first full-scale proof of AAW technology. Development Development of the initial concept was done with wind-tunnel testing in the mid 1980s under Air Force c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Compliant Wing
An adaptive compliant wing is a wing which is flexible enough for aspects of its shape to be changed in flight. Flexible wings have a number of benefits. Conventional flight control mechanisms operate using hinges, resulting in disruptions to the airflow, vortices, and in some cases, separation of the airflow. These effects contribute to the drag of the aircraft, resulting in less efficiency and higher fuel costs. Flexible aerofoils can manipulate aerodynamic forces with less disruptions to the flow, resulting in less aerodynamic drag and improved fuel economy. Shape adaptation Changing the shape of an aerodynamic surface has a direct effect on its aerodynamic properties. According to the flow condition and to the initial shape of the part, each shape variation (curvature, incidence, twist...) can have a different impact on the resulting forces and moments. This characteristic is actively pursued in adaptive wings which – by nature of their distributed compliance – can att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
