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Folding Propeller
A folding propeller is a type of propeller whose blades automatically fold out when the engine is turning, and then fold back (or "feather") when the engine stops. Folding propellers are found on sailing yachts, on model airplanes, and increasingly on self-launching gliders and small motor gliders, such as the Aériane Swift PAS. Their purpose of folding propellers is to reduce drag when sailing or soaring, respectively. Folding propellers are spun outwards by centrifugal force when the engine is turning, but when the engine stops, the pressure of airflow or waterflow forces the blades back. Typically, the blades are geared together so that they open and close in unison. Folding propellers used mainly to be two-bladed, but 3-bladed and 4-bladed versions are now available. The arguments for and against folding propellers are: Self-actuating variable pitch propellers A self-feathering propeller is not more efficient than a fixed bladed prop, as neither type can adopt an opti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folding Propeller - Gori Two Bladed
Fold, folding or foldable may refer to: Arts, entertainment, and media * ''Fold'' (album), the debut release by Australian rock band Epicure * Fold (poker), in the game of poker, to discard one's hand and forfeit interest in the current pot *Above the fold and below the fold, the positioning of news items on a newspaper's front page according to perceived importance *Paper folding, or ''origami'', the art of folding paper Science, technology, and mathematics Biology *Protein folding, the physical process by which a polypeptide folds into its characteristic and functional three-dimensional structure **Folding@home, a powerful distributed-computing project for simulating protein folding * Fold coverage, quality of a DNA sequence *Skin fold, an area of skin that folds Computing *Fold (higher-order function), a type of programming operation on data structures * fold (Unix), a computer program used to wrap lines to fit in a specified width *Folding (DSP implementation), a transformat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailing Yacht
A sailing yacht (US ship prefixes SY or S/Y), is a leisure craft that uses sails as its primary means of propulsion. A yacht may be a sail or power vessel used for pleasure, cruising, or racing. There is no standard definition, so the term applies here to sailing vessels that have a cabin with amenities that accommodate overnight use. To be termed a "yacht", as opposed to a "boat", such a vessel is likely to be at least in length and have been judged to have good aesthetic qualities. Sailboats that do not accommodate overnight use or are smaller than are not universally called yachts. Sailing yachts in excess of are generally considered to be superyachts. Sailing yachts are actively used in sport and are among categories recognized by the governing body of sailing sports, World Sailing. Etymology The term ''yacht'' originates from the Dutch word ''jacht'' (pl. ''jachten'', which means "hunt"), and originally referred to light, fast sailing vessels that the Dutch Republic na ... [...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 the least 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] |
Motor Glider
A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing Aircraft#Heavier-than-air – aerodynes, aerodyne equipped with a means of propulsion (MoP), capable of sustained Lift (soaring), soaring flight without thrust from the means of propulsion. History In 1935, an occasional or auxiliary motor that could be retracted was suggested by Sir John Carden. This was incorporated into the Carden-Baynes Auxiliary that first flew on 8 August of the same year. A later version of the Budig glider was powered. Types Most motor gliders are equipped with a Propeller (aircraft), propeller, which may be fixed, feathered (e.g. AMS-Flight Carat), or retractable. However jet engine-powered motorgliders are now available from some manufacturers, some of which are intended for use only as "sustainer" engines, i.e. for sustaining gliding flight rather than as self-launching aircraft. Fixed or feath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aériane Swift
The Aériane Swift is a lightweight (48 kg) foot-launched tailless sailplane whose rigid wings have a span of 40 feet. The Swift has been succeeded by the "Swift'Lite". Although designed in California, Swift aircraft are now manufactured by Aériane, a European firm based in Gembloux, Belgium. Aériane first manufactured the Swift under licence, but the firm is now the sole manufacturer. Design & development The Swift (an acronym for 'Swept Wing with Inboard Flap for Trim') was originally conceived as a rigid hang glider with sailplane-like performance. Bright Star Gliders had developed the 1989 U.S. National Hang Gliding Championship winning Odyssey prototype. Meanwhile Professor Ilan Kroo and a group of graduate students at Stanford University had developed the Stanford SWIFT design project. When Brian Porter of Bright Star met Stanford student Steve Morris, the projects merged. Bright Star constructed the revised SWIFT and its first flight took place in December 1989.I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centripetal Force
A centripetal force (from Latin ''centrum'', "center" and ''petere'', "to seek") is a force that makes a body follow a curved path. Its direction is always orthogonal to the motion of the body and towards the fixed point of the instantaneous center of curvature of the path. Isaac Newton described it as "a force by which bodies are drawn or impelled, or in any way tend, towards a point as to a centre". In Newtonian mechanics, gravity provides the centripetal force causing astronomical orbits. One common example involving centripetal force is the case in which a body moves with uniform speed along a circular path. The centripetal force is directed at right angles to the motion and also along the radius towards the centre of the circular path. The mathematical description was derived in 1659 by the Dutch physicist Christiaan Huygens. Formula The magnitude of the centripetal force on an object of mass ''m'' moving at tangential speed ''v'' along a path with radius of curvatu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brunton Autoprop
{{disambiguation, geo ...
Brunton may refer to: Places * Brunton, Northumberland, England (near Alnwick) * Low Brunton, Northumberland, England (near Hexham) *Brunton, Wiltshire, England *Brunton Memorial Ground, Radlett, Hertfordshire, England * Brunton, Fife, Scotland; a location in the U.K. Other uses * Brunton (surname) *Brunton, Inc., manufacturers of the Brunton compass See also * Colmar Brunton, a market research company *Brunton compass A Brunton compass, properly known as the Brunton Pocket Transit, is a precision compass made by Brunton, Inc. of Riverton, Wyoming. The instrument was patented in 1894 by Canadian-born geologist David W. Brunton. Unlike most modern compasses, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V-Prop
The V-Prop is an automatic self-powering electronic variable-pitch propeller developed by Silence Aircraft, the manufacturers of the Silence Twister single-seat elliptical-winged kitplane. Design and development The V-Prop was fitted to the prototype Twister and to some of the Twisters built in the EU. Designed by brothers Thomas and Mattheus Strieker, this microprocessor-controlled automatic propeller has a vaned spinner ahead of the main spinner. The main spinner is fixed to the output shaft in the normal fashion; but the vaned spinner is free to contra-rotate, and in doing so both generates its own power and derives rpm data that it uses to determine the ideal blade angle. The unit then automatically adjusts the blades between the coarse and fine positions. On the ground, the electronic control system can be tailored to suit each aircraft by varying some soldered connections, which give some 16 options.Silence Aircraft, (2005) ''Manual for the Silent R 1,61m V 3 and V2, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable-pitch Propeller (marine)
In marine propulsion, a variable-pitch propeller is a type of propeller with blades that can be rotated around their long axis to change the blade pitch. Reversible propellers—those where the pitch can be set to negative values—can also create reverse thrust for braking or going backwards without the need to change the direction of shaft revolution. A controllable pitch propeller (CPP) can be efficient for the full range of rotational speeds and load conditions, since its pitch will be varied to absorb the maximum power that the engine is capable of producing. When fully loaded, a vessel will need more propulsion power than when empty. By varying the propeller blades to the optimal pitch, higher efficiency can be obtained, thus saving fuel. A vessel with a VPP can accelerate faster from a standstill and can decelerate much more effectively, making stopping quicker and safer. A CPP can also improve vessel maneuverability by directing a stronger flow of water onto the ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
