Wing

Wing

A wing is a surface used to produce lift for flight through the air or another gaseous medium. The wing shape is usually an airfoil. The word originally referred only to the foremost limbs of birds, but has been extended to include the wings of insects (see insect wing), bats, pterosaurs, and aircraft.

A wing's "aerodynamic quality" is expressed as a Lift-to-drag ratio. The lift generated by a wing at a given speed and angle of attack can be 1-2 orders of magnitude greater than the drag. This means that a significantly smaller thrust force can be applied to propel the wing through the air in order to obtain a specified lift.

Design features

Airplane wings may feature some of the following:
*A rounded leading edge cross-section
*A sharp trailing edge cross-section
*Leading-edge devices such as slats, slots, or extensions
*Trailing-edge devices such as flaps
*Ailerons (usually near the wingtips) to provide roll control
*Spoilers on the upper surface to disrupt lift and additional roll control
*Vortex generators to help prevent flow separation in transonic flow
*Wing fences to keep flow attached to the wing by stopping boundary layer separation from spreading
*Dihedral, or a positive wing angle to the horizontal. This gives inherent stability in roll. Anhedral, or a negative wing angle to the horizontal, has a destabilising effect
*Folding wings allow more aircraft to be carried in the confined space of the hangar of an aircraft carrier.

cience of wings

The science of wings is one of the principal applications of the science of aerodynamics.In order for a wing to produce lift it has to be at a positive angle to the airflow. In that case a low pressure region is generated on the upper surface of the wing which draws the air above the wing downwards towards what would otherwise be a void after the wing had passed. On the underside of the wing a high pressure region forms accelerating the air there downwards out of the path of the oncoming wing. The pressure difference between these two regions produces an upwards force on the wing, called lift.

The pressure differences, the acceleration of the air and the lift on the wing are intrinsically one mechanism. It is therefore possible to derive the value of one by calculating another. For example lift can be calculated by reference to the pressure differences or by calculating the energy used to accelerate the air. Both approaches will result in the same answer if done correctly. Debates over which mathematical approach is the more convenient can be wrongly perceived as differences of opinion about the principles of flight and often create unnecessary confusion in the mind of the layman.

For a more detailed coverage see lift (force).

A common misconception is that it is the shape of the wing that is essential to generate lift by having a longer path on the top rather than the underside. This is not the case, thin flat wings can produce lift efficiently and aircraft with cambered wings can fly inverted as long as the nose of the aircraft is pointed high enough so as to present the wing at a positive angle of attack to the airflow.

The common aerofoil shape of wings is due to a large number of factors many of them not at all related to aerodynamic issues, for example wings need strength and thus need to be thick enough to contain structural members. They also need room to contain items such as fuel, control mechanisms and retracted undercarriage. The primary aerodynamic input to the wing’s cross sectional shape is the need to keep the air flowing smoothly over the entire surface for the most efficient operation. In particular, there is a requirement to prevent the low-pressure gradient that accelerates the air down the back of the wing becoming too great and effectively “sucking” the air off the surface of the wing. If this happens the wing surface from that point backwards becomes substantially ineffective.

The shape chosen by the designer is a compromise dependent upon the intended operational ranges of airspeed, angles of attack and wing loadings. Usually aircraft wings have devices, such as flaps, which allow the pilot to modify shape and surface area of the wing to be able to change its operating characteristics in flight.

In 1948 Francis Rogallo invented the fully limp flexible wing which ushered new possibilities for aircraft. Near in time Domina Jalbert invented flexible un-sparred ram-air airfoiled thick wings. These two new branches of wings have been since extensively studied and applied in new branches of aircraft, especially altering the personal recreational aviation landscape.

The science of wings applies in other areas beyond conventional fixed-wing aircraft, including:
*Hang gliders which use wings from fully-flexible (paragliders, gliding parachutes) wings, flexible wings (framed sail wings), to rigid wings.
*Kites which use a vast variety of wings.
*Aeromodelling
*Helicopters which use a rotating wing with a variable pitch or angle to provide a directional force
*The space shuttle which uses its wings only for lift during its descent
*Some racing cars, especially Formula One cars, which use upside-down wings to give cars greater adhesion at high speeds over 100mph.
*Sailing boats which use sails as vertical wings with variable fullness and direction to move across water.

Structures with the same purpose as wings, but designed to operate in liquid media, are generally called fins or hydroplanes, with hydrodynamics as the governing science. Applications arise in craft such as hydrofoils and submarines. Sailing boats use both fins and wings.

ee also

*Flight
*Planform
*Wing configuration
*Bird flight
*Flight feather
*Insect flight
*List of soaring birds
*Flying and gliding animals

External links

* [http://www.npr.org/templates/story/story.php?storyId=3875411 Demystifying the Science of Flight] - Audio segment on NPR's Talk of the Nation Science Friday
* [http://www.grc.nasa.gov/WWW/K-12/airplane/short.html NASA's explanations and simulations]
* [http://aerodyn.org/Wings/ Advanced Topics in Aerodynamics] Wings for all speeds
* [http://www.nurseminerva.co.uk/adapt/evolutio.htm Evolution of flight] in animals


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  • Wing — Wing, n. [OE. winge, wenge; probably of Scand. origin; cf. Dan. & Sw. vinge, Icel. v[ae]ngr.] [1913 Webster] 1. One of the two anterior limbs of a bird, pterodactyl, or bat. They correspond to the arms of man, and are usually modified for flight …   The Collaborative International Dictionary of English

  • Wing — heißen die Orte: Wing (Alabama), Ort in den USA Wing (Buckinghamshire), Ort in England Ort der All Saints Church (Wing) Wing (Oakham) in Leicestershire, Mize Maze in England Wing (Rutland), Ort in England Port Wing (Wisconsin), Stadt in den USA… …   Deutsch Wikipedia

  • wing — /wing/, n. 1. either of the two forelimbs of most birds and of bats, corresponding to the human arms, that are specialized for flight. 2. either of two corresponding parts in flightless birds, which may be rudimentary, as in certain ratite birds …   Universalium

  • wing — [wiŋ] n. [ME winge, weng < ON vaengr (for IE base see WIND2): the word replaced OE fether, wing, FEATHER] 1. a) either of the two feathered forelimbs of a bird, fully developed for flying, as in most birds, or insufficiently developed for… …   English World dictionary

  • Wing On — (zh c|c=永安) is a department store in Hong Kong. It was founded in 1907, and it is the second Chinese owned department store in Hong Kong. It has five outlets providing 360,000 square feet (33,400 square metre) of shopping space.Its founders are… …   Wikipedia

  • wing — ► NOUN 1) a modified forelimb or other appendage enabling a bird, bat, insect, or other creature to fly. 2) a rigid horizontal structure projecting from both sides of an aircraft and supporting it in the air. 3) a part of a large building,… …   English terms dictionary

  • wing — (n.) late 12c., wenge, from O.N. vængr wing of a bird, aisle, etc. (Cf. Dan., Swed. vinge wing ), of unknown origin, perhaps from a P.Gmc. *we ingjaz and ultimately from PIE root *we blow (Cf. O.E. wawan to blow; see WIND (Cf. wind) (n.)).… …   Etymology dictionary

  • Wing — Wing, v. t. [imp. & p. p. {Winged}; p. pr. & vb. n. {Winging}.] 1. To furnish with wings; to enable to fly, or to move with celerity. [1913 Webster] Who heaves old ocean, and whowings the storms. Pope. [1913 Webster] Living, to wing with mirth… …   The Collaborative International Dictionary of English

  • WinG — (sprich: Win Gee) ist eine Grafik Programmierschnittstelle für Windows 3.1, die bis Windows 98 Second Edition unterstützt wurde und anschließend komplett in die Graphics Device Interface (GDI) übernommen wurde. Grund für ihre Entwicklung waren… …   Deutsch Wikipedia

  • Wing — Wing, ND U.S. city in North Dakota Population (2000): 124 Housing Units (2000): 89 Land area (2000): 0.589750 sq. miles (1.527446 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.589750 sq. miles (1.527446 sq.… …   StarDict's U.S. Gazetteer Places

  • Wing, ND — U.S. city in North Dakota Population (2000): 124 Housing Units (2000): 89 Land area (2000): 0.589750 sq. miles (1.527446 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.589750 sq. miles (1.527446 sq. km) FIPS… …   StarDict's U.S. Gazetteer Places

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