Continuously Variable Valve Timing
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Continuously Variable Valve Timing
In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with variable valve lift systems. There are many ways in which this can be achieved, ranging from mechanical devices to electro-hydraulic and camless systems. Increasingly strict emissions regulations are causing many automotive manufacturers to use VVT systems. Two-stroke engines use a power valve system to get similar results to VVT. Background theory The valves within an internal combustion engine are used to control the flow of the intake and exhaust gases into and out of the combustion chamber. The timing, duration and lift of these valve events has a significant impact on engine performance. Without variable valve timing or variable valve lift, the valve timing is the same for all engine speeds and conditions, therefore compromises are neces ...
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K20 Head
K, or k, is the eleventh letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''kay'' (pronounced ), plural ''kays''. The letter K usually represents the voiceless velar plosive. History The letter K comes from the Greek letter Κ ( kappa), which was taken from the Semitic kaph, the symbol for an open hand. This, in turn, was likely adapted by Semitic tribes who had lived in Egypt from the hieroglyph for "hand" representing /ḏ/ in the Egyptian word for hand, ⟨ ḏ-r-t⟩ (likely pronounced in Old Egyptian). The Semites evidently assigned it the sound value instead, because their word for hand started with that sound. K was brought into the Latin alphabet with the name ''ka'' /kaː/ to differentiate it from C, named ''ce'' (pronounced /keː/) and Q, named ''qu'' and pronounced /kuː/. In the earliest Latin inscriptions, the letters C, K and Q were all used ...
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Cutoff (steam Engine)
In a steam engine, cutoff is the point in the piston stroke at which the inlet valve is closed. On a steam locomotive, the cutoff is controlled by the reversing gear. The point at which the inlet valve closes and stops the entry of steam into the cylinder from the boiler plays a crucial role in the control of a steam engine. Once the valve has closed, steam trapped in the cylinder expands adiabatically. The steam pressure drops as it expands. A late cutoff delivers full steam pressure to move the piston through its entire stroke, for maximum start-up forces. But, since there will still be unexploited pressure in the cylinder at the end of the stroke, this is achieved at the expense of engine efficiency. In this situation the steam will still have considerable pressure remaining when it is exhausted resulting in the characteristic “chuff chuff” sound of a steam engine. An early cutoff has greater thermodynamic efficiency but results in a lower Mean effective pressure so less ...
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Rotational Speed
Rotational frequency (also known as rotational speed or rate of rotation) of an object Rotation around a fixed axis, rotating around an axis is the frequency of rotation of the object. Its unit is revolution per minute (rpm), cycle per second (cps), etc. The symbol for rotational frequency is \nu (the Greek alphabet, Greek lowercase letter Nu (letter), nu). Speed#Tangential speed, Tangential speed ''v'', rotational frequency \nu, and radial distance ''r'', are related by the following equation: :v = 2\pi r\nu :v = r\omega An algebraic rearrangement of this equation allows us to solve for rotational frequency: :\nu = v/2\pi r :\omega = v/r Thus, the tangential speed will be directly proportional to ''r'' when all parts of a system simultaneously have the same ''ω'', as for a wheel, disk, or rigid wand. The direct proportionality of ''v'' to ''r'' is not valid for the planets, because the planets have different rotational frequencies. Rotational frequency can measure, for e ...
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Lycoming R-7755
Lycoming may refer to the following, most of which are at least partly in Lycoming County, Pennsylvania, United States: Geography * Lycoming, New York, a hamlet * Lycoming County, Pennsylvania * Lycoming Township, Lycoming County, Pennsylvania * Lycoming Creek, a tributary of the West Branch Susquehanna River Other uses * Lycoming Engines, a manufacturer of aircraft engines, and its successor Textron Lycoming * Lycoming Mall, a shopping mall of Interstate 180 * Lycoming College, a small, private, liberal arts college in Williamsport, Pennsylvania * , a World War II attack transport See also * Old Lycoming Township, Lycoming County, Pennsylvania Old Lycoming Township is a township in Lycoming County, Pennsylvania, United States. The population was 4,973 at the 2020 census down from 4,938 in 2010. It is part of the Williamsport Metropolitan Statistical Area. History Old Lycoming Townshi ... * Lycoming Valley Railroad, a shortline railroad along the West Branch Susquehanna ...
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Langley Research Center
The Langley Research Center (LaRC or NASA Langley), located in Hampton, Virginia, United States of America, is the oldest of NASA's field centers. It directly borders Langley Air Force Base and the Back River on the Chesapeake Bay. LaRC has focused primarily on aeronautical research, but has also tested space hardware such as the Apollo Lunar Module. In addition, many of the earliest high-profile space missions were planned and designed on-site. Langley was also considered a potential site for NASA's Manned Spacecraft Center prior to the eventual selection of Houston, Texas. Established in 1917 by the National Advisory Committee for Aeronautics (NACA), the research center devotes two-thirds of its programs to aeronautics and the rest to space. LaRC researchers use more than 40 wind tunnels to study and improve aircraft and spacecraft safety, performance, and efficiency. Between 1958 and 1963, when NASA (the successor agency to NACA) started Project Mercury, LaRC served as the ...
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Radial Engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is called a "star engine" in some other languages. The radial configuration was commonly used for aircraft engines before gas turbine engines became predominant. Engine operation Since the axes of the cylinders are coplanar, the connecting rods cannot all be directly attached to the crankshaft unless mechanically complex forked connecting rods are used, none of which have been successful. Instead, the pistons are connected to the crankshaft with a master-and-articulating-rod assembly. One piston, the uppermost one in the animation, has a master rod with a direct attachment to the crankshaft. The remaining pistons pin their connecting rods' attachments to rings around the edge of the master rod. Extra "rows" of radial cylinders can be added i ...
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Bristol Jupiter
The Bristol Jupiter was a British nine-cylinder single-row piston radial engine built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developments turned it into one of the finest engines of its era. The Jupiter was widely used on many aircraft designs during the 1920s and 1930s. Thousands of Jupiters of all versions were produced, both by Bristol and abroad under licence. A turbo-supercharged version of the Jupiter known as the Orion suffered development problems and only a small number were produced. The "Orion" name was later re-used by Bristol for an unrelated turboprop engine. Design and development The Jupiter was designed during World War I by Roy Fedden of Brazil Straker and later Cosmos Engineering. The first Jupiter was completed by Brazil Straker in 1918 and featured three carburettors, each one feeding three of the engine's nine cylinders via a spiral deflector housed ins ...
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Clerget
Clerget-Blin (full name being ''Société Clerget-Blin et Cie'') was a French precision engineering company formed in 1913 by the engineer and inventor Pierre Clerget and industrialist Eugène Blin. In 1939, the company was absorbed into the ''Groupe d'étude des moteurs à huile lourde'' (GEHL; "Diesel Engine Study Group"), which was further merged into SNECMA in 1947. Products The Clerget-Blin company mainly produced aircraft engines, their successful rotary engine designs were also built in Britain by companies such as Gwynnes Limited, Ruston Proctor and Gordon Watney, to increase the output in the times of World War I.Lumsden 2003, p.133. See also *List of aircraft engine manufacturers This is a list of aircraft engine manufacturers both past and present. 0–9 * 2si – US * 3WMiguel Vidal, Ricardo. ''El Motor de Aviación de la A a la Z. ''Aeroteca, 2012. A * A.V. Roe * Abadal * ABC Motors — UK * ABECO * Aberg ... Notes Bibliography * Gunston, Bi ...
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Léon Serpollet
Léon Serpollet (4 October 1858 – 1 February 1907) was a French engineer and developer of flash steam boilers and steam automobiles. Léon Serpollet was born in Culoz, in the Ain department of France in 1859, son of the carpenter Auguste Serpollet. He went into the family business with his brother Henri (1848-1915) producing circular saws and wood working machines. It was when seeking to power their workshops that Henri came up with the idea of flash steam generation, with a patent applied for on 25 October 1879. Leon went to Paris to study engineering at the Conservatoire national des arts et métiers, and at the same time he continued to develop the flash steam concept with his brother by post. In 1886 the two brothers arrived at their best design of flash steam boiler, and then shortly afterwards they went into business building flash steam boilers, initially small scale to power lighting systems and pumps, but soon to power tricycles and steam boats, and eventually to ...
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Poppet Valve
A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically ground at a 45° bevel to seal against a corresponding valve seat ground into the rim of the chamber being sealed. The shaft travels through a valve guide to maintain its alignment. A pressure differential on either side of the valve can assist or impair its performance. In exhaust applications higher pressure against the valve helps to seal it, and in intake applications lower pressure helps open it. The poppet valve was invented in 1833 by American E.A.G. Young of the New Castle and Frenchtown Turnpike and Railroad Company, Newcastle and Frenchtown Railroad. Young had patented his idea, but the 1836 U.S. Patent Offic ...
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Trip Valve
Trip may refer to: Arts and entertainment Fictional characters * Trip (''Pokémon''), a ''Pokémon'' character * Trip (Power Rangers), in the American television series ''Time Force Power Rangers'' * Trip, in the 2013 film '' Metallica Through the Never'' * Trip Fontaine, in the novel ''The Virgin Suicides'' * Trip Tucker, in the television series ''Star Trek: Enterprise'' Film and television Films * ''The Trip'' (1967 film), an American film directed by Roger Corman * ''The Trip'' (2002 film), an American gay romance film * ''A Trip'', a 2011 Slovenian film * ''Trip'' (film), a 2021 Indian Tamil-language film * ''The Trip'' (2021 film), a Norwegian action-comedy film Television =Series= * ''The Trip'' (1999 TV series), a British documentary series * ''The Trip'' (2010 TV series), a British sitcom * ''Trip'', an upcoming comedy program on Quibi =Episodes= * "The Trip" (''The Middle'') * "The Trip" (''Seinfeld'') * "The Trip" (''Six Feet Under'') * "The Trip" (''This ...
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Centrifugal Governor
A centrifugal governor is a specific type of governor with a feedback system that controls the speed of an engine by regulating the flow of fuel or working fluid, so as to maintain a near-constant speed. It uses the principle of proportional control. Centrifugal governors, also known as "centrifugal regulators" and "fly-ball governors", were invented by Christiaan Huygens and used to regulate the distance and pressure between millstones in windmills in the 17th century. In 1788, James Watt adapted one to control his steam engine where it regulates the admission of steam into the cylinder(s), a development that proved so important he is sometimes called the inventor. Centrifugal governors' widest use was on steam engines during the Steam Age in the 19th century. They are also found on stationary internal combustion engines and variously fueled turbines, and in some modern striking clocks. A simple governor does not maintain an exact speed but a speed range, since under increasi ...
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