wing

wing: see airfoil; airplane; flight.

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wing

In zoology, one of the paired structures certain animals use for flying. Bat and bird wings are modifications of the vertebrate forelimb. In birds, the fingers are reduced and the forearm is lengthened. The primary flight feathers propel the bird forward, and the secondaries (on the upper wing) provide lift. Bat wings consist of a membrane stretched over slender, elongated arm and hand bones. Insect wings are folds of integument (“skin”). Most insects have two pairs of wings; dipterans (flies) have only one developed pair, and beetles have two but use only one for flying. The two wings on a side usually move together, but dragonfly wings work independently.

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WinG

(WINdows Games) A programming interface (API) that lets Windows application developers access the video frame buffer directly. It allows game programs to be written to run as fast in Windows as they do under DOS.

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wing

1. either of the modified forelimbs of a bird that are covered with large feathers and specialized for flight in most species

2. one of the organs of flight of an insect, consisting of a membranous outgrowth from the thorax containing a network of veins

3. either of the organs of flight in certain other animals, esp the forelimb of a bat

4. 

a. a half of the main supporting surface on an aircraft, confined to one side of it

b. the full span of the main supporting surface on both sides of an aircraft

c. an aircraft designed as one complete wing

d. a position in flight formation, just to the rear and to one side of an aircraft

5. 

a. an organ or apparatus resembling a wing

b. Anatomy any bodily structure resembling a wing

6. Botany

a. either of the lateral petals of a sweetpea or related flower

b. any of various outgrowths of a plant part, esp the process on a wind-dispersed fruit or seed

7. Brit the part of a car body that surrounds the wheels

8. any affiliate of or subsidiary to a parent organization

9. a faction or group within a political party or other organization

10. the space offstage to the right or left of the acting area in a theatre

11. a surface fitted to a racing car to produce aerodynamic download to hold it on the road at high speed

12. an insignia in the form of stylized wings worn by a qualified aircraft pilot

13. any of various flattened organs or extensions in lower animals, esp when used in locomotion

14. the side of a hold alongside a ship's hull

15. a jetty or dam for narrowing a channel of water

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wing [wiŋ]

(aerospace engineering)

A major airfoil.

An airfoil on the side of an airplane's fuselage or cockpit, paired off by one on the other side, the two providing the principal lift for the airplane.

(geology)

vesicle

(zoology)

Any of the paired appendages serving as organs of flight on many animals.

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Wing

A lifting surface of a heavier-than-air object, either bird or airplane. Lift is created by a pressure difference between the upper and lower surfaces of the wing, the average pressure on the upper surface being lower. The average velocity on the upper surface is larger than on the lower surface, resulting in the lifting pressure difference in accordance with Bernoulli's theorem. The velocity difference is caused by having a greater curvature on the wing upper surface, or a positive wing angle of attack (that is, leading edge up), or both. The amount of lift is proportional to the angle of attack, the wing area, the air density, and the square of the velocity. See Aerodynamic force, Subsonic flight

The important physical characteristics of a wing are wing area, measured in the plan or top view, the span or distance from the left wing tip to the right wing tip, the aspect ratio, the taper ratio, and the thickness ratios of the airfoils. The aspect ratio is the ratio of the span to the average chord. The chord of a wing is the distance from the leading edge to the trailing edge. In all but the simplest airplanes, the chord varies along the span, being largest at the root. The taper ratio is the ratio of the tip chord to the root chord. Airfoils are the cross-sectional shapes of wings as defined by the intersections with planes parallel to the oncoming airstream and perpendicular to the plane of the wing surface. The thickness ratio is the ratio of the maximum thickness of an airfoil to the chord and often varies between the root and tip. If an airfoil has greater curvature on the upper surface than on the lower surface, the mean line midway between the upper and lower surfaces is curved. The amount of this curvature is called camber. All of these wing characteristics affect flight efficiency and must be carefully chosen. See Aircraft design

There is a particular angle of attack of a wing that provides the necessary lift with the least drag. Wing area selection attempts to have the airplane fly at this angle of attack at the desired speed and within the range of desirable altitudes. Of course, takeoff and landing fields are important in area selection. A larger wing area permits slower flight, which is associated with shorter takeoff acceleration distances and shorter stopping distances after landing.

Wings must be designed to stall safely. Above the maximum angle of attack at which the flow will remain smoothly attached to the wing surface, there is a sharp loss of lift and a large increase in drag. This is known as the stall, a condition that is normally avoided. Wings are designed to stall near the root first so that the tendency to roll sharply is minimized and the ailerons on the outer wing remain effective. This is done by varying the airfoil sections and thickness ratios across the span in a careful manner.

The flight of airplanes is controlled primarily by varying the magnitude and direction of the wing lift and by varying the thrust or power contributed by the engines. An important aspect of flight is the speed, which is controlled by adjusting the wing angle of attack with respect to the oncoming airstream. The angle of attack is adjusted by varying the angle of the elevator, a control surface usually located on the horizontal tail. After adjusting the flight speed by using the elevators, the angle of the flight path, zero for level flight, is controlled by setting the engine thrust.

The direction of flight is basically controlled by the angle of bank of the wing. When the wing is level and the resultant force, or lift, is vertical, the airplane flies in a straight line. Ailerons are trailing-edge flaps on the outer part of the wing that deflect in opposite directions on the left and right sides of the airplane. When the airplane banks or rolls because of the deflection of ailerons, the lift force is tilted toward the side since it remains perpendicular to the banked wing. This provides a sidewise force which accelerates the airplane in a direction perpendicular to the flight path and thereby curves the flight path. Application of the rudder keeps the airplane pointed into the wind during the turn, although the vertical tail will do much of that job even without rudder deflection

High-speed aircraft also use spoilers, essentially plates ahead of the flaps, to lose lift on only one side to roll the airplane. These spoilers are also used symmetrically to slow down an airplane and increase the rate of descent. Spoilers are also used after touchdown to quickly reduce lift and dump the weight on the braked wheels, thereby greatly improving the stopping effectiveness.

Wings also carry moving elements that serve lift-increase functions. Trailing-edge flaps (see illustration) inboard of the ailerons increase the lift that can be carried before the stall. Thus the minimum flight speed can be decreased. Leading-edge flaps and slats (see illustration) are used to increase the angle of attack for stall and further reduce the minimum flight speed. The primary purpose of increasing the lift capability and obtaining the lowest flight speed is to reduce the required field lengths for takeoff and landing or to reduce the necessary wing area. See Flight controls

Wings also serve as fuel tanks, a function that sometimes sets the minimum wing area—especially on small aircraft such as executive jets. Wing thickness ratio is important in determining the volume available for fuel within the wing. Wings often house all or part of the landing gear. Engines are mounted on the wing of many aircraft. See Aircraft engine, Airplane, Landing gear