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Tumblewing
A tumblewing or "tumble wing" or "tumbling wing" is a glider or kite wing design which rotates about an axis transverse to the apparent wind, not necessarily horizontal. Tumble wings are frequently employed in wind turbines (such as the Savonius design), and are also used in some types of confetti. Tumble wings may be made of any material that supports some stiffness for form, such as paper, plastic, metal, composites or wood. Many leaves falling from trees become tumble wing gliders. Tumbling wings generate lift by alternately flying and stalling as the angle of incidence changes with the spinning motion (see magnus effect and flettner rotor). Its mode of flight is more akin to confetti than traditional fixed-wing aircraft; however, several model aircraft, such as flettner airplanes, have been built with tumbling wings for lift. Tumble wings are employed as the wing of kite systems, a type of rotary kite, and many such patents exist. Because it has no need for ballast, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walkalong Glider
A walkalong glider is a lightweight, slow-flying model aircraft designed to be kept aloft by controllable slope soaring in the rising air generated by the pilot who walks along with the glider as it flies, usually holding a paddle. Hands or even the forehead can also be used to create an updraft. This type of soaring differs from other types of slope soaring in that the orographic lift (or "hill") is following the plane as it flies in the air and thus no other wind is required. Types of walkalong gliders have been patented. Some walkalong glider designs have been named, such as the air surfer, the windrider, the tumblewing and the follow foil. Walkalong gliding has also been referred to as controllable slope soaring but should not be confused with dynamic soaring. Ground effect should not be confused with ridge lift when explaining how walkalong gliders stay up. Ground effect involves a horizontal surface. Ridge lift requires a sloping surface. In ground effect the air does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confetti
Confetti are small pieces or streamers of paper, mylar, or metallic material which are usually thrown at celebrations, especially parades and weddings. The origins are from the Latin ''confectum'', with ''confetti'' the plural of Italian ''confetto'', small sweet. Modern paper confetti trace back to symbolic rituals of tossing grains and sweets during special occasions, traditional for numerous cultures throughout history as an ancient custom dating back to pagan times, but adapted from sweets and grains to paper through the centuries. Confetti are manufactured in multiple colors, and commercially available confetti come in many different shapes. A distinction is made between confetti and glitter; glitter is smaller than confetti (pieces usually no larger than 1mm) and is universally shiny. Most table confetti are also shiny. While they are called metallic confetti they are actually metallized PVC. The most popular shape is the star. Seasonally, Snowflake Confetti are the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Savonius Wind Turbine
Savonius wind turbines are a type of vertical-axis wind turbine (VAWT), used for converting the force of the wind into torque on a rotating shaft. The turbine consists of a number of aerofoils, usually—but not always—vertically mounted on a rotating shaft or framework, either ground stationed or tethered in airborne systems. Origin The Savonius wind turbine was invented by the Finnish engineer Sigurd Johannes Savonius in 1922 and patented in 1926. Europeans had earlier experimented with curved blades on vertical wind turbines for many decades. The earliest mention is by the Bishop of Csanád County, Fausto Veranzio, who was also an engineer. He wrote in his 1616 book ''Machinae novae'' about several vertical axis wind turbines with curved or V-shaped blades. None of his or any other earlier examples reached the state of development achieved by Savonius. In his biography, there is mention of his intention to develop a turbine-type rotor similar to the Flettner rotor, but se ... [...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 increases.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', p. 486. Aviation Supplies & Academics, 1997. This occurs when the critical angle of attack of the foil is exceeded. The critical angle of attack is typically about 15°, but it may vary significantly depending on the fluid, foil, and Reynolds number. Stalls in fixed-wing flight are often experienced as a sudden reduction in lift as the pilot increases the wing's angle of attack and exceeds its critical angle of attack (which may be due to slowing down below stall speed in level flight). 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 altitude or controlled flight with wings stalled by replacing lost wing lift with engine or propeller t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of Incidence (aerodynamics)
On fixed-wing aircraft, the angle of incidence (sometimes referred to as the ''mounting angle'' or ''setting angle'') is the angle between the chord line of the wing where the wing is mounted to the fuselage, and a reference axis along the fuselage (often the direction of minimum drag, or where applicable, the longitudinal axis). The angle of incidence is fixed in the design of the aircraft, and with rare exceptions, cannot be varied in flight. The term can also be applied to horizontal surfaces in general (such as canards or horizontal stabilizers) for the angle they make relative the longitudinal axis of the fuselage. The figure to the right shows a side view of an airplane. The extended chord line of the wing root (red line) makes an angle with the longitudinal axis (roll axis) of the aircraft (blue line). Wings are typically mounted at a small positive angle of incidence, to allow the fuselage to have a low angle with the airflow in cruising flight. Angles of incidence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnus Effect
The Magnus effect is an observable phenomenon commonly associated with a spinning object moving through a fluid. The path of the spinning object is deflected in a manner not present when the object is not spinning. The deflection can be explained by the difference in pressure of the fluid on opposite sides of the spinning object. The Magnus effect is dependent on the speed of rotation. The most readily observable case of the Magnus effect is when a spinning sphere (or cylinder) curves away from the arc it would follow if it were not spinning. It is often used by association football and volleyball players, baseball pitchers, and cricket bowlers. Consequently, the phenomenon is important in the study of the physics of many ball sports. It is also an important factor in the study of the effects of spinning on guided missiles—and has some engineering uses, for instance in the design of rotor ships and Flettner aeroplanes. Topspin in ball games is defined as spin about a ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flettner Rotor
A Flettner rotor is a smooth cylinder with disc end plates which is spun along its long axis and, as air passes at right angles across it, the Magnus effect causes an aerodynamic force to be generated in the direction perpendicular to both the long axis and the direction of airflow.Seifert, Jost;A review of the Magnus effect in aeronautics, ''Progress in Aerospace Sciences'' Vol. 55, 2012, pp.17–45. The rotor sail is named after the German aviation engineer and inventor Anton Flettner, who started developing the rotor sail in the 1920s. In a rotor ship, the rotors stand vertically and lift is generated at right angles to the wind, to drive the ship forwards. In a rotor airplane, the rotor extends sideways in place of a wing and upwards lift is generated. Magnus effect The Magnus effect is named after Gustav Magnus, the German physicist who investigated it. It describes the force generated by fluid flow over a rotating body, at right angles to both the direction of flow and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be achieved by generating lift (force), aerodynamic lift associated with gliding flight, gliding or air propulsion, propulsive thrust, aerostatically using buoyancy, or by ballistics, ballistic movement. Many things can fly, from Flying and gliding animals, animal aviators such as birds, bats and insects, to natural gliders/parachuters such as patagium, patagial animals, anemochorous seeds and ballistospores, to human inventions like aircraft (airplanes, helicopters, airships, balloons, etc.) and rockets which may propel spacecraft and spaceplanes. The engineering aspects of flight are the purview of aerospace engineering which is subdivided into aeronautics, the study of vehicles that travel through the atmosphere, and astronautics, the stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-wing Aircraft
A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft (in which the wings form a rotor mounted on a spinning shaft or "mast"), and ornithopters (in which the wings flap in a manner similar to that of a bird). The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft and airplanes that use wing morphing are all examples of fixed-wing aircraft. Gliding fixed-wing aircraft, including free-flying gliders of various kinds and tethered kites, can use moving air to gain altitude. Powered fixed-wing aircraft (airplanes) that gain forward thrust from an engine include powered paragliders, powered hang gliders and some ground effect vehicles. Most fixed-wing aircraft are flown by a pilot on board the craft, but some ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons. The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called '' aeronautics.'' Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others. History Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flettner Airplane
A Flettner airplane is a type of rotor airplane which uses a Flettner rotor to provide lift. The rotor comprises a spinning cylinder with circular end plates and, in an aircraft, spins about a spanwise horizontal axis. When the aircraft moves forward, the Magnus effect creates lift. Anton Flettner, after whom the rotor is named, used it successfully as the sails of a rotor ship. He also suggested its use as a wing for a rotor airplane. The Butler Ames Aerocycle was built in 1910 and tested aboard a warship. There is no record of it having flown. The Plymouth A-A-2004 was built for Zaparka in 1930 by three anonymous American inventors. It was reported to have made successful flights over Long Island Sound. An inherent safety concern is that if power to the rotating drums were lost—even if thrust was maintained—the aircraft would lose its ability to generate lift as the drum slowed and it would not be able to sustain flight. See also * Cyclogyro * FanWing * Servo tab __N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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