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Trailing Edge
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. Essential flight control surfaces are attached here to control the direction of the departing air flow, and exert a controlling force on the aircraft. Such control surfaces include ailerons on the wings for roll control, elevators on the tailplane controlling pitch, and the rudder on the fin controlling yaw. Elevators and ailerons may be combined as elevons on tailless aircraft. The shape of the trailing edge is of prime importance in the aerodynamic function of any aerodynamic surface. George Batchelor has written about: :“ ... the remarkable controlling influence exerted by the sharp trailing edge of an aerofoil on the circulation.”Batchelor, G. K. (1967), ''An Introduction to Fluid Dynamics'', p.438, Cambridge University Press. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trailing Edge
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. Essential flight control surfaces are attached here to control the direction of the departing air flow, and exert a controlling force on the aircraft. Such control surfaces include ailerons on the wings for roll control, elevators on the tailplane controlling pitch, and the rudder on the fin controlling yaw. Elevators and ailerons may be combined as elevons on tailless aircraft. The shape of the trailing edge is of prime importance in the aerodynamic function of any aerodynamic surface. George Batchelor has written about: :“ ... the remarkable controlling influence exerted by the sharp trailing edge of an aerofoil on the circulation.”Batchelor, G. K. (1967), ''An Introduction to Fluid Dynamics'', p.438, Cambridge University Press. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tailless Aircraft
In aeronautics, a tailless aircraft is an aircraft with no other horizontal aerodynamic surface besides its main wing. It may still have a fuselage, vertical tail fin (vertical stabilizer), and/or vertical rudder. Theoretical advantages of the tailless configuration include low parasitic drag as on the Horten H.IV soaring glider and good stealth characteristics as on the Northrop B-2 Spirit bomber. Disadvantages include a potential sensitivity to trim. Tailless aircraft have been flown since the pioneer days; the first stable aeroplane to fly was the tailless Dunne D.5, in 1910. The most successful tailless configuration has been the tailless delta, especially for combat aircraft, though the most familiar tailless delta is the Concorde airliner. NASA has used the 'tailless' description for the novel X-36 research aircraft which has a canard foreplane but no vertical fin. Aircraft configuration A tailless aircraft has no other horizontal surface besides its main wing. The aer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-sectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flap (aircraft)
A flap is a high-lift device used to reduce the 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 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 of the outboard half, maintaining aileron effectiveness and reduci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-servo Tab
__NOTOC__ A servo tab is a small hinged device installed on an aircraft control surface to assist the movement of the control surfaces. Introduced by the German firm Flettner, servo tabs were formerly known as Flettner tabs. Servo tabs are not true servomechanisms, as they do not employ negative feedback to keep the control surfaces in a desired position; they only provide a mechanical advantage to the pilot. Servo tabs A servo tab, or balance tab, moves in the direction opposite to the desired movement of the control surface. It deflects airflow, generating force on the whole control surface in the desired direction. The tab has a leverage advantage, being located well aft of the control surface hinge line, and thus its airflow deflection moves the control surface in the opposite direction, overcoming the resistance generated by the airflow deflection of the control surface. This has the effect of reducing the control force required from the pilot to move the controls. In som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Servo Tab
__NOTOC__ A servo tab is a small hinged device installed on an aircraft control surface to assist the movement of the control surfaces. Introduced by the German firm Flettner, servo tabs were formerly known as Flettner tabs. Servo tabs are not true servomechanisms, as they do not employ negative feedback to keep the control surfaces in a desired position; they only provide a mechanical advantage to the pilot. Servo tabs A servo tab, or balance tab, moves in the direction opposite to the desired movement of the control surface. It deflects airflow, generating force on the whole control surface in the desired direction. The tab has a leverage advantage, being located well aft of the control surface hinge line, and thus its airflow deflection moves the control surface in the opposite direction, overcoming the resistance generated by the airflow deflection of the control surface. This has the effect of reducing the control force required from the pilot to move the controls. In som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trim Tabs
Trim tabs are small surfaces connected to the trailing edge of a larger control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the boat or aircraft in a particular desired attitude without the need for the operator to constantly apply a control force. This is done by adjusting the angle of the tab relative to the larger surface. Changing the setting of a trim tab adjusts the neutral or resting position of a control surface (such as an elevator or rudder). As the desired position of a control surface changes (corresponding mainly to different speeds), an adjustable trim tab will allow the operator to reduce the manual force required to maintain that position—to zero, if used correctly. Thus the trim tab acts as a servo tab. Because the center of pressure of the trim tab is farther away from the axis of rotation of the control surface than the center of pressure of the control surface, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circulation (fluid Dynamics)
In physics, circulation is the line integral of a vector field around a closed curve. In fluid dynamics, the field is the fluid velocity field. In electrodynamics, it can be the electric or the magnetic field. Circulation was first used independently by Frederick Lanchester, Martin Kutta and Nikolay Zhukovsky. It is usually denoted Γ (Greek uppercase gamma). Definition and properties If V is a vector field and dl is a vector representing the differential length of a small element of a defined curve, the contribution of that differential length to circulation is dΓ: :\mathrm\Gamma=\mathbf\cdot \mathrm\mathbf=, \mathbf, , \mathrm\mathbf, \cos \theta. Here, ''θ'' is the angle between the vectors V and dl. The circulation Γ of a vector field V around a closed curve ''C'' is the line integral: :\Gamma=\oint_\mathbf\cdot \mathrm d \mathbf. In a conservative vector field this integral evaluates to zero for every closed curve. That means that a line integral between any two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Batchelor
George Keith Batchelor FRS (8 March 1920 – 30 March 2000) was an Australian applied mathematician and fluid dynamicist. He was for many years a Professor of Applied Mathematics in the University of Cambridge, and was founding head of the Department of Applied Mathematics and Theoretical Physics (DAMTP). In 1956 he founded the influential ''Journal of Fluid Mechanics'' which he edited for some forty years. Prior to Cambridge he studied at Melbourne High School and University of Melbourne. As an applied mathematician (and for some years at Cambridge a co-worker with Sir Geoffrey Taylor in the field of turbulent flow), he was a keen advocate of the need for physical understanding and sound experimental basis. His ''An Introduction to Fluid Dynamics'' (CUP, 1967) is still considered a classic of the subject, and has been re-issued in the ''Cambridge Mathematical Library'' series, following strong current demand. Unusual for an 'elementary' textbook of that era, it presented a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevons
Elevons or tailerons are aircraft control surfaces that combine the functions of the elevator (used for pitch control) and the aileron (used for roll control), hence the name. They are frequently used on tailless aircraft such as flying wings. An elevon that is not part of the main wing, but instead is a separate tail surface, is a stabilator (but stabilators are also used for pitch control only, with no roll function, as on the Piper Cherokee series of aircraft). Elevons are installed on each side of the aircraft at the trailing edge of the wing. When moved in the same direction (up or down) they will cause a pitching force (nose up or nose down) to be applied to the airframe. When moved differentially, (one up, one down) they will cause a rolling force to be applied. These forces may be applied simultaneously by appropriate positioning of the elevons e.g. one wing's elevons completely down and the other wing's elevons partly down. An aircraft with elevons is controlled as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull (watercraft), hull or fuselage, thus imparting a turning or yaw (rotation), yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize Drag (physics), hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
