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Société D'Etudes Pour La Propulsion Par Réaction
The ''Société d'Études pour la Propulsion par Réaction'' (SEPR) (in french: Jet Propulsion Research Company) was a French research and manufacturing company founded in 1944 which specialised in the development of liquid-fuelled rocket engines during the 1950s, 60s, 70s and 80s. The SEPR 841 is a liquid-fuelled rocket engine used as an auxiliary power unit for the Dassault Mirage III mixed-power high-altitude interceptor aircraft of the 1960s. The engine was one of several similar developed by SEPR. Mixed-power In the 1950s, there was much concern in Western Europe about attacks by fleets of high-flying bombers, such as the Tu-95 ''Bear''. These pre-dated the development of either practical afterburners or surface-to-air missiles and so means to improve the performance of conventional aircraft were sought. Particularly in France, and to some extent in the UK, mixed-power interceptor aircraft were studied, with a combination of jet and rocket power. The rocket would be used f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, fashion, gastronomy, and science. For its leading role in the arts and sciences, as well as its very early system of street lighting, in the 19th century it became known as "the City of Light". Like London, prior to the Second World War, it was also sometimes called the capital of the world. The City of Paris is the centre of the Île-de-France region, or Paris Region, with an estimated population of 12,262,544 in 2019, or about 19% of the population of France, making the region France's primate city. The Paris Region had a GDP of €739 billion ($743 billion) in 2019, which is the highest in Europe. According to the Economist Intelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planform (aircraft)
The wing configuration of a fixed-wing aircraft (including both gliders and powered aeroplanes) is its arrangement of lifting and related surfaces. Aircraft designs are often classified by their wing configuration. For example, the Supermarine Spitfire is a conventional low wing cantilever monoplane of straight elliptical planform with moderate aspect ratio and slight dihedral. Many variations have been tried. Sometimes the distinction between them is blurred, for example the wings of many modern combat aircraft may be described either as cropped compound deltas with (forwards or backwards) swept trailing edge, or as sharply tapered swept wings with large leading edge root extensions (or LERX). Some are therefore duplicated here under more than one heading. This is particularly so for variable geometry and combined (closed) wing types. Most of the configurations described here have flown (if only very briefly) on full-size aircraft. A few theoretical designs are also notab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbopump
A turbopump is a propellant pump with two main components: a rotodynamic pump and a driving gas turbine, usually both mounted on the same shaft, or sometimes geared together. They were initially developed in Germany in the early 1940s. The purpose of a turbopump is to produce a high-pressure fluid for feeding a combustion chamber or other use. There are two types of turbopumps: a centrifugal pump, where the pumping is done by throwing fluid outward at high speed, or an axial-flow pump, where alternating rotating and static blades progressively raise the pressure of a fluid. Axial-flow pumps have small diameters but give relatively modest pressure increases. Although multiple compression stages are needed, axial flow pumps work well with low-density fluids. Centrifugal pumps are far more powerful for high-density fluids but require large diameters for low-density fluids. History Early development High-pressure pumps for larger missiles had been discussed by rocket pioneers su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Alcohol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, volatile, colourless, flammable liquid with a distinctive alcoholic odour similar to that of ethanol (potable alcohol). A polar solvent, methanol acquired the name wood alcohol because it was once produced chiefly by the destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide. Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl benzoate, anisole, peroxyacids, as well as a host of more specialised chemicals. Occurrence Small amounts of methanol are present in normal, healthy human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylidine
Xylidine can refer to any of the six isomers of xylene amine, or any mixture of them. The chemical formula of xylidines is C8H11N or, more descriptively, (CH3)2C6H3NH2. The CAS number for the isomer mixture is . They are colorless solids or liquids, although commercial samples can appear yellow or darker. They are miscible with ethanol and diethyl ether and slightly soluble in water. Xylidines are used in production of pigments and dyestuffs, and various antioxidants, agrochemicals, pharmaceuticals, hypergolic propellants, and many other organic chemicals. In World War II, xylidine was an important antiknock agent in very high performance aviation gasolines. Its purpose was to permit high levels of boost pressure in multiple-stage turbochargers, and thus high power at high altitudes, without causing detonation that would destroy the engine. The high pressures brought high temperatures of inlet air, making engines prone to knock. This use and storage stabilization methods were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furfuryl Alcohol
Furfuryl alcohol is an organic compound containing a furan substituted with a hydroxymethyl group. It is a colorless liquid, but aged samples appear amber. It possesses a faint odor of burning and a bitter taste. It is miscible with but unstable in water. It is soluble in common organic solvents. Synthesis Furfuryl alcohol is manufactured industrially by hydrogenation of furfural, which is itself typically produced from waste bio-mass such as corncobs or sugar cane bagasse. As such furfuryl alcohol may be considered a green chemical. One-pot systems have been investigated to produce furfuryl alcohol directly from xylose using solid acid catalysts. Reactions It undergoes many reactions including Diels-Alder additions to electrophilic alkenes and alkynes. Hydroxymethylation gives 1,5-bis(hydroxymethyl)furan. Hydrolysis gives levulinic acid. Upon treatment with acids, heat and/or catalysts, furfuryl alcohol can be made to polymerize into a resin, poly(furfuryl alcohol). Hydrog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypergolic
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Common hypergolic propellants are difficult to handle due to their extreme toxicity and/or corrosiveness. In contemporary usage, the terms "hypergol" and "hypergolic propellant" usually mean the most common such propellant combination: dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). History In 1935, Hellmuth Walter discovered that hydrazine hydrate was hypergolic with high-test peroxide of 80-83%. He was probably the first to discover this phenomenon, and set to work devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Electric Lightning
The English Electric Lightning is a British fighter aircraft that served as an interceptor during the 1960s, the 1970s and into the late 1980s. It was capable of a top speed of above Mach 2. The Lightning was designed, developed, and manufactured by English Electric, which was later merged into the newly-formed British Aircraft Corporation. Later the type was marketed as the BAC Lightning. It was operated by the Royal Air Force (RAF), the Kuwait Air Force (KAF), and the Royal Saudi Air Force (RSAF). A unique feature of the Lightning's design is the vertical, staggered configuration of its two Rolls-Royce Avon turbojet engines within the fuselage. The Lightning was designed and developed as an interceptor to defend the V bomber airfields from attack by anticipated future nuclear-armed supersonic Soviet bombers such as what emerged as the Tupolev Tu-22, but it was subsequently also required to intercept other bomber aircraft such as the Tupolev Tu-16 and the Tupolev Tu-9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
