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Washout (aviation)
Washout is a characteristic of aircraft wing design which deliberately changes the Lift (force), lift distribution across the Wingspan, span of an aircraft’s wing. The wing is designed so that the angle of incidence (aerodynamics), angle of incidence is greater at the wing roots and decreases across the span, becoming lowest at the wing tip. This is usually to ensure that at Stall (flight), stall speed the wing root stalls before the wing tips, providing the aircraft with continued aileron control and some resistance to Spin (flight), spinning. Washout may also be used to modify the spanwise lift distribution to reduce lift-induced drag. Design considerations Washout is commonly achieved by designing the Wing#Artificial Wings, wing with a slight Wing twist, twist, reducing the angle of incidence (aerodynamics), angle of incidence from root to tip, and therefore causing a lower angle of attack at the tips than at the roots. This feature is sometimes referred to as geometrica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washout Diagram , w ...
Washout may refer to: * Washout (erosion), the erosion of a soft surface by a gush of water * Washout (aeronautics), the practice of building a wing with a twist from root to tip * Washout (comics), a mutant character in the Marvel Comics universe * "Washout", a song by The Fallout Trust * "Washout", a 1991 episode of the PBS show Shining Time Station * "Washout", a story from The Railway Series book "Thomas Goes Home" * Washed Out, the stage name of chillwave musician Ernest Greene * The well drilling process for enlarging a drill hole in an oil well * A term for a sporting event cancelled due to rain; see Rainout (sports) * An alternate name for a run-in period, a common phase in clinical research * Radiocontrast washout Contrast CT, or contrast-enhanced computed tomography (CECT), is X-ray computed tomography (CT) using radiocontrast. Radiocontrasts for X-ray CT are generally iodine-based types. This is useful to highlight structures such as blood vessels that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swept Wing
A swept wing is a wing angled either backward or occasionally forward from its root rather than perpendicular to the fuselage. Swept wings have been flown since the pioneer days of aviation. Wing sweep at high speeds was first investigated in Germany as early as 1935 by Albert Betz and Adolph Busemann, finding application just before the end of the Second World War. It has the effect of delaying the shock waves and accompanying aerodynamic drag rise caused by fluid compressibility near the speed of sound, improving performance. Swept wings are therefore almost always used on jet aircraft designed to fly at these speeds. The term "swept wing" is normally used to mean "swept back", but variants include forward sweep, variable sweep wings and oblique wings in which one side sweeps forward and the other back. The delta wing is also aerodynamically a form of swept wing. Reasons for sweep There are three main reasons for sweeping a wing: 1. to arrange the center of gravity o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adverse Yaw
Adverse yaw is the natural and undesirable tendency for an aircraft to yaw in the opposite direction of a roll. It is caused by the difference in lift and drag of each wing. The effect can be greatly minimized with ailerons deliberately designed to create drag when deflected upward and/or mechanisms which automatically apply some amount of coordinated rudder. As the major causes of adverse yaw vary with lift, any fixed-ratio mechanism will fail to fully solve the problem across all flight conditions and thus any manually operated aircraft will require some amount of rudder input from the pilot in order to maintain coordinated flight. History Adverse yaw was first experienced by the Wright brothers when they were unable to perform controlled turns in their 1901 glider which had no vertical control surface. Orville Wright later described the glider's lack of directional control. Causes Adverse yaw is a secondary effect of the inclination of the lift vectors on the wing due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Span Loading
In aeronautics, the aspect ratio of a wing is the ratio of its span to its mean chord. It is equal to the square of the wingspan divided by the wing area. Thus, a long, narrow wing has a high aspect ratio, whereas a short, wide wing has a low aspect ratio.Kermode, A.C. (1972), ''Mechanics of Flight'', Chapter 3, (p.103, eighth edition), Pitman Publishing Limited, London Aspect ratio and other features of the planform are often used to predict the aerodynamic efficiency of a wing because the lift-to-drag ratio increases with aspect ratio, improving the fuel economy in powered airplanes and the gliding angle of sailplanes. Definition The aspect ratio \text is the ratio of the square of the wingspan b to the projected wing area S, which is equal to the ratio of the wingspan b to the standard mean chord \text: \text \equiv \frac = \frac Mechanism As a useful simplification, an airplane in flight can be imagined to affect a cylinder of air with a diameter equal to the wingsp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albion H
Albion is an alternative name for Great Britain. The oldest attestation of the toponymy, toponym comes from the Greek language. It is sometimes used poetically and generally to refer to the island, but is less common than "Britain" today. The name for Scotland in most of the Celtic languages is related to Albion: ''Alba'' in Scottish Gaelic, ''Albain'' (genitive ''Alban'') in Irish language, Irish, ''Nalbin'' in Manx language, Manx and ''Alban'' in Welsh language, Welsh and Cornish language, Cornish. These names were later Latinisation of names, Latinised as ''Albania'' and Anglicisation, Anglicised as ''Albany'', which were once alternative names for Scotland. ''New Albion'' and ''Albionoria'' ("Albion of the North") were briefly suggested as name of Canada, names of Canada during the period of the Canadian Confederation. Francis Drake gave the name New Albion to what is now California when he landed there in 1579. Etymology The toponym in English is thought to derive from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grumman X-29
The Grumman X-29 is an American experimental aircraft that tested a forward-swept wing, canard control surfaces, and other novel aircraft technologies. Funded by NASA, the United States Air Force and DARPA, the X-29 was developed by Grumman, and the two built were flown by NASA and the United States Air Force. The aerodynamic instability of the X-29's airframe required the use of computerized fly-by-wire control. Composite materials were used to control the aeroelastic divergent twisting experienced by forward-swept wings, and to reduce weight. The aircraft first flew in 1984, and two X-29s were flight tested through 1991. Design and development Two X-29As were built by Grumman after the proposal had been chosen over a competing one involving a General Dynamics F-16 Fighting Falcon. The X-29 design made use of the forward fuselage and nose landing gear from two existing F-5A Freedom Fighter airframes (63-8372 became 82-0003 and 65-10573 became 82-0049). The control surface a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin (flight)
In flight dynamics a spin is a special category of stall resulting in autorotation (uncommanded roll) about the aircraft's longitudinal axis and a shallow, rotating, downward path approximately centred on a vertical axis. Spins can be entered intentionally or unintentionally, from any flight attitude if the aircraft has sufficient yaw while at the stall point. In a normal spin, the wing on the inside of the turn stalls while the outside wing remains flying. It is possible for both wings to stall, but the angle of attack of each wing, and consequently its lift and drag, are different. Either situation causes the aircraft to autorotate toward the stalled wing due to its higher drag and loss of lift. Spins are characterized by high angle of attack, an airspeed below the stall on at least one wing and a shallow descent. Recovery and avoiding a crash may require a specific and counter-intuitive set of actions. A spin differs from a spiral dive, in which neither wing is stalled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bending Moment
In solid mechanics, a bending moment is the Reaction (physics), reaction induced in a structural element when an external force or Moment of force, moment is applied to the element, causing the element to bending, bend. The most common or simplest structural element subjected to bending moments is the Beam (structure), beam. The diagram shows a beam which is simply supported (free to rotate and therefore lacking bending moments) at both ends; the ends can only react to the Shear stress, shear loads. Other beams can have both ends fixed (known as encastre beam); therefore each end support has both bending moments and shear reaction loads. Beams can also have one end fixed and one end simply supported. The simplest type of beam is the cantilever, which is fixed at one end and is free at the other end (neither simple nor fixed). In reality, beam supports are usually neither absolutely fixed nor absolutely rotating freely. The internal reaction loads in a cross section (geometry), cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing Tips
A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of shapes, including: * Squared-off * Aluminium tube bow * Rounded * Hoerner style * Winglets * Drooped tips * Raked wingtips * Tip tanks * Sails * Fences * End plates Winglets have become popular additions to high speed aircraft to increase fuel efficiency by reducing drag from wingtip vortices. In lower speed aircraft, the effect of the wingtip shape is less apparent, with only a marginal performance difference between round, square, and Hoerner style tips The slowest speed aircraft, STOL aircraft, may use wingtips to shape airflow for controllability at low airspeeds. Wing tips are also an expression of aircraft design style, so their shape may be influenced by marketing considerations as well as by aerodynamic requirements. Wing tips ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wingtip Device
Wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag (physics), drag. Although there are several types of wing tip devices which function in different manners, their intended effect is always to reduce an aircraft's drag. Such devices reduce drag by increasing the height of the lifting system, without greatly increasing the wingspan. Extending the span would reduce lift-induced drag, but would increase parasitic drag and would require boosting the strength and weight of the wing. At some point, there is no net benefit from further increased span. There may also be operational considerations that limit the allowable wingspan (e.g. available width at Gate (airport), airport gates). Physics When a conventional wing generates lift, it also experiences lift-induced drag. Higher pressure air under the wing flows to the lower pressure surface on top at the wingtip, which results in a vortex caused by the forward motion of the aircraft. Eri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stall Strips
A stall strip is a small component fixed to the leading edge of the wing of an airplane to modify its aerodynamic characteristics.Crane, Dale: ''Dictionary of Aeronautical Terms'', third edition, page 487. Aviation Supplies & Academics, 1997. These stall strips may be necessary for the airplane to comply with type certification requirements. A stall strip typically consists of a small piece of material, usually aluminium, triangular in cross section and often 6-12 inches (15–30 cm) in length. It is riveted or bonded to the wing’s leading edge. Some airplanes have one stall strip on each wing. Some airplanes have only one stall strip on one wing. Operation A stall strip initiates flow separation on a region of the upper surface of the wing during flight at high angle of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a Airfoil#Airfoil terminology, reference line on a body (often the chord (aircraft), chord line of an airfoil) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing Fence
A wing is a type of fin that produces both lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a 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 foils that move through water are found on hydrofoil power vessels and 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 limbs of birds (in addition to the architectural aisle). But in recent centuries the word's meaning has extended to include lift producing appendages of insects, bats, pterosaurs, boomerangs, some sai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
