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General Electric GE36
The General Electric GE36 was an experimental aircraft engine, a hybrid between a turbofan and a turboprop, known as an unducted fan (UDF) or propfan. The GE36 was developed by GE Aviation, General Electric Aircraft Engines, with its CFM International equal partner Snecma taking a 35 percent share of development. Development was cancelled in 1989. Development General Electric (GE) started performing studies and component test work on the concept that would become the UDF in 1981, based on the initial results of early National Aeronautics and Space Administration (NASA) propfan technology studies that the aerospace agency first released to engine makers in 1980. GE then followed up with full-scale development testing of the GE36 starting in 1982. NASA gave GE a $20.4 million contract in February 1984 to study the concept after the company showed the agency its work in December 1983, as NASA's own propfan research efforts were advancing at a slower pace and were dependent on additio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WikiProject Aircraft
A WikiProject, or Wikiproject, is a Wikimedia movement affinity group for contributors with shared goals. WikiProjects are prevalent within the largest wiki, Wikipedia, and exist to varying degrees within sister projects such as Wiktionary, Wikiquote, Wikidata, and Wikisource. They also exist in different languages, and translation of articles is a form of their collaboration. During the COVID-19 pandemic, CBS News noted the role of Wikipedia's WikiProject Medicine in maintaining the accuracy of articles related to the disease. Another WikiProject that has drawn attention is WikiProject Women Scientists, which was profiled by '' Smithsonian'' for its efforts to improve coverage of women scientists which the profile noted had "helped increase the number of female scientists on Wikipedia from around 1,600 to over 5,000". On Wikipedia Some Wikipedia WikiProjects are substantial enough to engage in cooperative activities with outside organizations relevant to the field at issue. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testbed Aircraft
A testbed aircraft is an aeroplane, helicopter or other kind of aircraft intended for flight research or testing the aircraft concepts or on-board equipment. These could be specially designed or modified from serial production aircraft. Use of testbed aircraft For example, in development of new aircraft engines, these are fitted to a testbed aircraft for flight testing, before certification. For this adaptation it is required, among other changes, that new instrumentation wiring and equipment, fuel system and piping, as well as structural modifications of wing. The Folland Fo.108 (nicknamed the "Folland Frightful") was a dedicated engine testbed aircraft of the 1940s. The aircraft had a mid fuselage cabin for test instrumentation and observers. Twelve were built and provided to British aero-engine companies. A large number of aircraft-testbeds have been produced and tested since 1941 in the USSR and Russia by the Gromov Flight Research Institute. AlliedSignal, Honeywell Aerosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gearbox
Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differential, and final drive shafts. In the United States the term is sometimes used in casual speech to refer more specifically to the gearbox alone, and detailed usage differs. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and where different rotational speeds and torques are adapted. Often, a transmission has multiple gear ratios (or simply "gears") with the ability to switch between them as the speed varies. This switching may be done manually (by the operator) or automatically (by a control unit). Directional (forward and reverse) control may also be provided. Single-ratio transmissions also exist, which simply chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cincinnati, Ohio
Cincinnati ( ) is a city in the U.S. state of Ohio and the county seat of Hamilton County. Settled in 1788, the city is located at the northern side of the confluence of the Licking and Ohio rivers, the latter of which marks the state line with Kentucky. The city is the economic and cultural hub of the Cincinnati metropolitan area. With an estimated population of 2,256,884, it is Ohio's largest metropolitan area and the nation's 30th-largest, and with a city population of 309,317, Cincinnati is the third-largest city in Ohio and 64th in the United States. Throughout much of the 19th century, it was among the top 10 U.S. cities by population, surpassed only by New Orleans and the older, established settlements of the United States eastern seaboard, as well as being the sixth-most populous city from 1840 until 1860. As a rivertown crossroads at the junction of the North, South, East, and West, Cincinnati developed with fewer immigrants and less influence from Europe than Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farnborough Air Show
The Farnborough Airshow, officially the Farnborough International Airshow, is a trade exhibition for the aerospace and defence industries, where civilian and military aircraft are demonstrated to potential customers and investors. Since its first show in 1948, Farnborough has seen the debut of many famous planes, including the Vickers VC10, Concorde, the Eurofighter, the Airbus A380, and the Lockheed Martin F-35 Lightning II. At the 1958 show, the RAF's Black Arrows executed a 22-plane formation loop, setting a world record. The international trade show is put together every two years by FIL Farnborough International Ltd. and runs for five days. Until 2020, the show ran for a full week with trade visitors attending on the first five days and the weekend reserved for the general public. Programming takes place at the Farnborough Airport, which lies roughly 50 kilometres south-west of London. Status The Farnborough International Airshow is the second-largest show of its kind afte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transonic flow is seen at flight speeds close to the speed of sound (343 m/s at sea level), typically between Mach 0.8 and 1.2. The issue of transonic speed (or transonic region) first appeared during World War II. Pilots found as they approached the sound barrier the airflow caused aircraft to become unsteady. Experts found that shock waves can cause large-scale separation downstream, increasing drag and adding asymmetry and unsteadiness to the flow around the vehicle. Research has been done into weakening shock waves in transonic flight through the use of anti-shock bodies and supercritical airfoils. Most modern jet powered aircraft are engineered to operate at transonic air speeds. Transonic airspeeds see a rapid increase in drag from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Tunnel
Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft will fly. NASA uses wind tunnels to test scale models of aircraft and spacecraft. Some wind tunnels are large enough to contain full-size versions of vehicles. The wind tunnel moves air around an object, making it seem as if the object is flying. Most of the time, large powerful fans suck air through the tube. The object being tested is held securely inside the tunnel so that it remains stationary. The object can be an aerodynamic test object such as a cylinder or an airfoil, an individual component, a small model of the vehicle, or a full-sized vehicle. The air moving around the stationary object shows what would happen if the object was moving through the air. The motion of the air can be studied in different ways; smoke or dye can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contra-rotating
Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. Examples include some aircraft propellers, resulting in the maximum power of a single piston or turboprop engine to drive two propellers in opposite rotation. Contra-rotating propellers are also common in some marine transmission systems, in particular for large speed boats with planing hulls. Two propellers are arranged one behind the other, and power is transferred from the engine via planetary gear transmission. The configuration can also be used in helicopter designs termed coaxial rotors, where similar issues and principles of torque apply. Contra-rotating propellers should not be confused with counter-rotating propellers, a term which describes non-coaxial propellers on separate shafts; one turning clockwise and the other counter-clockwise. Tandem-rotor helicopters such as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach Number
Mach number (M or Ma) (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Moravian physicist and philosopher Ernst Mach. : \mathrm = \frac, where: : is the local Mach number, : is the local flow velocity with respect to the boundaries (either internal, such as an object immersed in the flow, or external, like a channel), and : is the speed of sound in the medium, which in air varies with the square root of the thermodynamic temperature. By definition, at Mach1, the local flow velocity is equal to the speed of sound. At Mach0.65, is 65% of the speed of sound (subsonic), and, at Mach1.35, is 35% faster than the speed of sound (supersonic). Pilots of high-altitude aerospace vehicles use flight Mach number to express a vehicle's true airspeed, but the flow field around a vehicle varies in three dimensions, with corresponding variations in local Mach number. The local spe ... [...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 (ship), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbofans
The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a portmanteau of "turbine" and "fan": the ''turbo'' portion refers to a gas turbine engine which achieves mechanical energy from combustion, and the ''fan'', a ducted fan that uses the mechanical energy from the gas turbine to force air rearwards. Thus, whereas all the air taken in by a turbojet passes through the combustion chamber and turbines, in a turbofan some of that air bypasses these components. A turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of these contributing to the thrust. The ratio of the mass-flow of air bypassing the engine core to the mass-flow of air passing through the core is referred to as the bypass ratio. The engine produces thrust through a combination of these two portions working together; engines that use more jet thrust relative to fan thrust are known as ''low-bypass turbofans'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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