|
Aileron Drag
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 it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft
An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, in a few cases, direct Powered lift, downward thrust from its engines. Common examples of aircraft include airplanes, rotorcraft (including helicopters), airships (including blimps), Glider (aircraft), gliders, Powered paragliding, paramotors, and hot air balloons. Part 1 (Definitions and Abbreviations) of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that aircraft "means a device that is used or intended to be used for flight in the air." The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called ''aeronautics.'' Aircrew, Crewed aircraft are flown by an onboard Aircraft pilot, pilot, whereas unmanned aerial vehicles ... [...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] |
Spoileron
In aeronautics, spoilerons (also known as spoiler ailerons or roll spoilers) are spoiler (aeronautics), spoilers that can be used asymmetrically as flight control surfaces to provide roll control. Operation Spoilerons flight dynamics (fixed-wing aircraft), roll an aircraft by reducing the lift (force), lift of the downward-going wing. Unlike ailerons, spoilers do not increase the lift and drag of the upward-going wing. A raised spoileron increases the drag on the down-going wing where it is deployed, causing the aircraft to Flight dynamics (fixed-wing aircraft), yaw in the direction of the turn. Spoilerons can be used to assist ailerons or to replace them entirely, as in the Boeing B-52 Stratofortress, B-52G which required an extra spoiler segment in place of ailerons present on other B-52 models. Purpose Spoilerons do not cause adverse yaw, unlike ailerons. They are used in situations where aileron action would produce excessive wing twist on a very flexible wing or if wide-sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeroelasticity
Aeroelasticity is the branch of physics and engineering studying the interactions between the inertial, elastic, and aerodynamic forces occurring while an elastic body is exposed to a fluid flow. The study of aeroelasticity may be broadly classified into two fields: ''static aeroelasticity'' dealing with the static or steady state response of an elastic body to a fluid flow, and ''dynamic aeroelasticity'' dealing with the body's dynamic (typically vibrational) response. Aircraft are prone to aeroelastic effects because they need to be lightweight while enduring large aerodynamic loads. Aircraft are designed to avoid the following aeroelastic problems: # divergence where the aerodynamic forces increase the twist of a wing which further increases forces; # control reversal where control activation produces an opposite aerodynamic moment that reduces, or in extreme cases reverses, the control effectiveness; and # flutter which is uncontained vibration that can lead to the destr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glider (sailplane)
A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplanes are aerodynamically streamlined and so can fly a significant distance forward for a small decrease in altitude. In North America the term 'sailplane' is also used to describe this type of aircraft. In other parts of the English-speaking world, the word 'glider' is more common. Types Gliders benefit from producing very low drag for any given amount of lift, and this is best achieved with long, thin wings, a slender fuselage and smooth surfaces with an absence of protuberances. Aircraft with these features are able to soar – climb efficiently in rising air produced by thermals or hills. In still air, sailplanes can glide long distances at high speed with a minimum loss of height in between. Sailplanes have rigid wings and either ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Havilland Tiger Moth
The de Havilland DH.82 Tiger Moth is a 1930s British biplane designed by Geoffrey de Havilland and built by the de Havilland, de Havilland Aircraft Company. It was operated by the Royal Air Force (RAF) and other operators as a primary trainer (aircraft), trainer aircraft. In addition to the type's principal use for ''ab initio'' training, the World War II, Second World War had RAF Tiger Moths operating in other capacities, including Maritime patrol aircraft, maritime surveillance and defensive anti-invasion preparations; some aircraft were even outfitted to function as armed light bombers. The Tiger Moth remained in service with the RAF until it was replaced by the de Havilland Canada DHC-1 Chipmunk, de Havilland Chipmunk during the early 1950s. Many of the military surplus aircraft subsequently entered into civilian operation. Many nations have used the Tiger Moth in both military and civilian applications, and it remains in widespread use as a recreational aircraft. It is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stall (flight)
In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack exceeds its critical value.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', p. 486. Aviation Supplies & Academics, 1997. The critical angle of attack is typically about 15°, but it may vary significantly depending on the fluid, foil – including its shape, size, and finish – and Reynolds number. Stalls in fixed-wing aircraft are often experienced as a sudden reduction in lift. It may be caused either by the pilot increasing the wing's angle of attack or by a decrease in the critical angle of attack. The former may be due to slowing down (below stall speed), the latter by accretion of ice on the wings (especially if the ice is rough). A stall does not mean that the engine(s) have stopped working, or that the aircraft has stopped moving—the effect is the same even in an unpowered glider aircraft. Vectored thrust in aircraft is used to maintain alti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Separation
In fluid dynamics, flow separation or boundary layer separation is the detachment of a boundary layer from a surface into a wake. A boundary layer exists whenever there is relative movement between a fluid and a solid surface with viscous forces present in the layer of fluid close to the surface. The flow can be externally, around a body, or internally, in an enclosed passage. Boundary layers can be either laminar or turbulent. A reasonable assessment of whether the boundary layer will be laminar or turbulent can be made by calculating the Reynolds number of the local flow conditions. Separation occurs in flow that is slowing down, with pressure increasing, after passing the thickest part of a streamline body or passing through a widening passage, for example. Flowing against an increasing pressure is known as flowing in an adverse pressure gradient. The boundary layer separates when it has travelled far enough in an adverse pressure gradient that the speed of the bounda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Profile Drag
Profile or profiles may refer to: Art, entertainment and media Music * Profile (Jan Akkerman album), ''Profile'' (Jan Akkerman album), 1973 * Profile (Githead album), ''Profile'' (Githead album), 2005 * Profile (Pat Donohue album), ''Profile'' (Pat Donohue album), 2005 * Profile (Duke Pearson album), ''Profile'' (Duke Pearson album), 1959 * ''Profiles (Nick Mason and Rick Fenn album), ''Profiles'' (Nick Mason and Rick Fenn album)'', a 1985 album by Nick Mason and Rick Fenn * Profiles (Gary McFarland album), ''Profiles'' (Gary McFarland album), a 1966 live album by Gary McFarland * Profile (Misako Odani album), ''Profile'' (Misako Odani album), 1997 * Profile (Wolfe Tones album), ''Profile'' (Wolfe Tones album) Film and television * Profile (2018 film), ''Profile'' (2018 film), a film directed by Timur Bekmambetov * Profile (1954 film), British thriller film * Profile (1955 TV series), ''Profile'' (1955 TV series) (1955–1957), a Canadian biographical television series * Profil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Principal Axes
An aircraft in flight is free to rotate in three dimensions: '' yaw'', nose left or right about an axis running up and down; ''pitch'', nose up or down about an axis running from wing to wing; and ''roll'', rotation about an axis running from nose to tail. The axes are alternatively designated as ''vertical'', ''lateral'' (or ''transverse''), and ''longitudinal'' respectively. These axes move with the vehicle and rotate relative to the Earth along with the craft. These definitions were analogously applied to spacecraft when the first crewed spacecraft were designed in the late 1950s. These rotations are produced by torques (or moments) about the principal axes. On an aircraft, these are intentionally produced by means of moving control surfaces, which vary the distribution of the net aerodynamic force about the vehicle's center of gravity. Elevators (moving flaps on the horizontal tail) produce pitch, a rudder on the vertical tail produces yaw, and ailerons (flaps on the wings t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
