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Aspect Ratio (aeronautics)
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 wing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASH 31 Mi Flug 001 20090421
Ash is the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non-gaseous residues that remain after something combustion, burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash (analytical chemistry), ash is the non-gaseous, non-liquid residue after complete combustion. Ashes as the end product of incomplete combustion are mostly mineral, but usually still contain an amount of combustible organic compound, organic or other Redox, oxidizable residues. The best-known type of ash is wood ash, as a product of wood combustion in campfires, fireplaces, etc. The darker the wood ashes, the higher the content of remaining charcoal from incomplete combustion. The ashes are of different types. Some ashes contain natural compounds that make soil Soil fertility, fertile. Others have chemical compounds that can be toxic but may break up in soil from chemical changes and microorganism activity. Like soap, ash is also a disin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Drag
Parasitic drag, also known as profile drag, is a type of aerodynamic drag that acts on any object when the object is moving through a fluid. Parasitic drag is defined as the combination of '' form drag'' and '' skin friction drag''. It is named as such because it is not useful, in contrast with lift-induced drag which is created when an airfoil generates lift. All objects experience parasitic drag, regardless of whether they generate lift. Parasitic drag comprises all types of drag except lift-induced drag, and the total drag on an aircraft or other object which generates lift is the sum of parasitic drag and lift-induced drag. Form drag Form drag arises because of the shape of the object. The general size and shape of the body are the most important factors in form drag; bodies with a larger presented cross-section will have a higher drag than thinner bodies; sleek ("streamlined") objects have lower form drag. Form drag follows the drag equation, meaning that it increases wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wingspan
The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan of , the official record for a living bird. The term wingspan, more technically 'extent' , is also used for other winged animals such as pterosaurs, bats, insects, etc., and other aircraft such as ornithopters. In humans, the term wingspan also refers to the arm span, which is the distance between the length from the end of an individual's arm (measured at the fingertips) to the individual's fingertips on the other arm when raised parallel to the ground at shoulder height. Wingspan of aircraft The wingspan of an aircraft is always measured in a straight line, from wingtip to wingtip, regardless of wing shape or sweep. Implications for aircraft design and animal evolution The lift from wings is proportional to their area, so the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurasian Sparrowhawk
The Eurasian sparrowhawk (''Accipiter nisus''), also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barred underparts; females and juveniles are brown above with brown barring below. The female is up to 25% larger than the male – one of the greatest size differences between the sexes in any bird species. Though it is a predator which specialises in catching woodland birds, the Eurasian sparrowhawk can be found in any habitat and often hunts garden birds in towns and cities. Males tend to take smaller birds, including Tit (bird), tits, finches and Old World sparrow, sparrows; females catch primarily Thrush (bird), thrushes and starlings but are capable of killing birds weighing or more. The Eurasian sparrowhawk is found throughout the temperate and subtropical parts of the Old World; whilst birds from the northern parts of the range Bird mig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eagle
Eagle is the common name for the golden eagle, bald eagle, and other birds of prey in the family of the Accipitridae. Eagles belong to several groups of Genus, genera, some of which are closely related. True eagles comprise the genus ''Aquila (bird), Aquila''. Most of the 68 species of eagles are from Eurasia and Africa. Outside this area, just 14 species can be found—two in North America, nine in Central and South America, and three in Australia. Eagles are not a natural group but denote essentially any kind of bird of prey large enough to hunt sizeable (about 50 cm long or more overall) vertebrates. Etymology The word "eagle" is borrowed into English from and , both derived ultimately from ("eagle"). It is cognate with terms such as , and . It is broadly synonymous with the less common English term "erne" or "earn", deriving from , from , in which it acts as the usual word for the bird. The Old English term is turn derived from and is cognate with other synonymous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains of short-tailed albatross show they lived there up to the Pleistocene, and occasional vagrants are found. Great albatrosses are among the largest of flying birds, with wingspans reaching up to and bodies over in length. The albatrosses are usually regarded as falling into four genera, but disagreement exists over the number of species. Albatrosses are highly efficient in the air, using dynamic soaring and slope soaring to cover great distances with little exertion. They feed on squid, fish, and krill by either scavenging, surface seizing, or diving. Albatrosses are colonial, nesting for the most part on remote oceanic islands, often with several species nesting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave Drag
In aeronautics, wave drag is a component of the aerodynamic drag In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or b ... on aircraft wings and fuselage, propeller blade tips and Shell (projectile), projectiles moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects,Clancy, L.J. (1975), ''Aerodynamics'', Section 11.7 and tends to present itself as a sudden and dramatic increase in drag as the vehicle increases speed to the critical Mach number. It is the sudden and dramatic rise of wave drag that leads to the concept of a sound barrier. Overview Wave drag is a component of pressure drag due to compressibility effects. It is caused by the formation of shock waves around a body. Shock waves create a considerable amount ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium, but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic speed, supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by Wave interference, constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable-sweep Wing
A variable-sweep wing, colloquially known as a "swing wing", is an airplane wing, or set of wings, that may be modified during flight, swept back and then returned to its previous straight position. Because it allows the aircraft's shape to be changed, it is a feature of a variable-geometry aircraft. A straight wing is most efficient for low-speed flight, but for an aircraft designed for transonic or supersonic flight it is essential that the wing be swept. Most aircraft that travel at those speeds usually have wings (either swept wing or delta wing) with a fixed sweep angle. These are simple and efficient wing designs for high speed flight, but there are performance tradeoffs. One is that the stalling speed is increased, necessitating long runways (unless complex high-lift wing devices are built in). Another is that the aircraft's fuel consumption during subsonic cruise is higher than that of an unswept wing. These tradeoffs are particularly acute for naval carrier-bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airbus A350
The Airbus A350 is a flight length, long-range, wide-body twin-engine airliner developed and produced by Airbus. The initial A350 design proposed in 2004, in response to the Boeing 787 Dreamliner, would have been a development of the Airbus A330 with composite wings, advanced winglets, and new efficient engines. Due to inadequate market support, Airbus switched in 2006 to a clean-sheet "XWB" (eXtra Wide Body) design, powered by two Rolls-Royce Trent XWB high bypass turbofan engines. The prototype first flew on 14 June 2013 from Toulouse, France. Type certification from the European Aviation Safety Agency (EASA) was obtained in September 2014, followed by certification from the Federal Aviation Administration (FAA) two months later. The A350 is the first Airbus aircraft largely made of carbon-fibre-reinforced polymers. The fuselage is designed around a 3-3-3 nine-across economy cross-section, an increase from the eight-across A330/A340 2-4-2 configuration. It has a common t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing 787
The Boeing 787 Dreamliner is an American wide-body airliner developed and manufactured by Boeing Commercial Airplanes. After dropping its unconventional Sonic Cruiser project, Boeing announced the conventional 7E7 on January 29, 2003, which focused largely on efficiency. The program was launched on April 26, 2004, with an order for 50 aircraft from All Nippon Airways (ANA), targeting a 2008 introduction. On July 8, 2007, a prototype 787 without major operating systems was rolled out; subsequently the aircraft experienced multiple delays, until its maiden flight on December 15, 2009. Type certification was received in August 2011, and the first 787-8 was delivered in September 2011 and entered commercial service on October 26, 2011, with ANA. At launch, Boeing targeted the 787 with 20% less fuel burn compared to aircraft like the Boeing 767. It could carry 200 to 300 passengers on point-to-point routes up to , a shift from hub-and-spoke travel. The twinjet is powere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airbus A380
The Airbus A380 is a very large wide-body airliner, developed and produced by Airbus until 2021. It is the world's largest passenger airliner and the only full-length double-deck jet airliner. Airbus studies started in 1988, and the project was announced in 1990 to challenge the dominance of the Boeing 747 in the long-haul market. The then-designated A3XX project was presented in 1994 and Airbus launched the €–billion ($10.7–billion) A380 programme on 19 December 2000. The first prototype was unveiled in Toulouse, France on 18 January 2005, commencing its first flight on 27 April 2005. It then obtained its type certificate from the European Aviation Safety Agency (EASA) and the US Federal Aviation Administration (FAA) on 12 December 2006. Due to difficulties with the electrical wiring, the initial production was delayed by two years and the development costs almost doubled. It was first delivered to Singapore Airlines on 15 October 2007 and entered service on 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
