1.
Henschel Hs 293
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The Henschel Hs 293 was a World War II German anti-ship guided missile, a radio controlled glide bomb with a rocket engine slung underneath it. It was designed by Herbert A. Wagner, the Hs 293 project was started in 1940, based on the Gustav Schwartz Propellerwerke pure glide bomb that was designed in 1939. The Schwartz design did not have a guidance system, instead. It was intended to be launched from a bomber at sufficient distance to keep the aircraft out of range of anti-aircraft fire. A Henschel team, under Dr. Herbert Wagner, developed it the year by adding an Walter HWK 109-507 rocket engine underneath. This allowed the bomb to be used from a lower altitude, some examples used the BMW 109-511 of 600 kg thrust. The elevator was operated with an electrically powered jackscrew as the proportional control. Remote flight control was provided through the Kehl-Straßburg link, with the Hs 293s control setup having no movable rudder on the ventral tailfin, the rocket provided for only a short burst of speed making range dependent on the height of launch. From a height of 1,400 m the Hs 293 had a range of about 12 km, the Hs 293 was intended to destroy unarmoured ships, unlike the unpowered, armour-piercing Fritz X, which used the same Kehl-Straßburg system. Five coloured flares were attached to the rear of the weapon to make it visible at a distance to the operator, during nighttime operations flashing lights instead of flares were used. The Allies put considerable effort into developing devices which jammed the radio link between Kehl transmitter and Straßburg receiver, jammers aboard U. S. Navy destroyer escorts were ineffective at first, as the frequencies selected for jamming were incorrect. On balance, the probability that a Hs 293 launched would actually strike a target was about the same at Anzio as it was during Operation Avalanche. Meanwhile, as attacks were taking place at Anzio, the United Kingdom began to deploy its Type 650 transmitter which employed a different approach, which proved quite successful. The Type 650 automatically defeated the receiver, regardless which radio frequency had been selected for an individual missile, there was also a tailless delta winged Hs 293F. In addition, there was a Hs 293H air-to-air model, over 1,000 were built, from 1942 onwards. The closest Allied weapon system in function and purpose to the Hs 293 series was the US Navys Bat unpowered, the Hs 293 also served as the basis for a number of developments, none completed. On August 25,1943, an Hs 293 was used in the first successful attack by a missile, striking the sloop HMS Bideford, however, as the warhead did not detonate. On August 27, the sinking of the British sloop HMS Egret by a squadron of 18 Dornier Do 217 carrying Hs 293s led to anti-U-boat patrols in the Bay of Biscay being temporarily suspended
2.
Liquid-propellant rocket
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A liquid-propellant rocket or liquid rocket is a rocket engine that uses liquid propellants. This permits the use of low-mass propellant tanks, resulting in a mass ratio for the rocket. An inert gas stored in a tank at a pressure is sometimes used instead of pumps in simpler small engines to force the propellants into the combustion chamber. These engines may have a mass ratio, but are usually more reliable. And are therefore used widely in satellites for orbit maintenance, some designs are throttleable for variable thrust operation and some may be restarted after a previous in-space shutdown. Liquid propellants are used in hybrid rockets, in which a liquid oxidizer is generally combined with a solid fuel. This seminal treatise on astronautics was published in 1903, but was not distributed outside Russia until years later, german V-2 inventor Wernher von Braun considered Paulet one of the fathers of aeronautics. The National Air & Space Museum in Washington, D. C. has a plaque honoring the memory of Paulet. He was the only known developer of liquid-propellant rocket engine experiments in the 19th century, however, he did not publish his work. In 1927 he wrote a letter to a newspaper in Lima, historians of early rocketry experiments, among them Max Valier, Willy Ley, and John D. Clark, have given differing amounts of credence to Paulets report. Paulet described laboratory tests of, but did not claim to have launched a liquid rocket. Wernher von Braun, in his book World History of Aeronautics states, Pedro Paulet was in Paris in those years, experimenting with his tiny two-and-a-half kilogram motor, by this act, Paulet should be considered the pioneer of the liquid fuel propulsion motor. Further, in his History of Rocketry and Space Travel, von Braun recognizes that by his efforts, Paulet helped man reach the Moon. The rocket, which was dubbed Nell, rose just 41 feet during a 2. 5-second flight that ended in a cabbage field, goddard proposed liquid propellants about fifteen years earlier and began to seriously experiment with them in 1921. In Germany, engineers and scientists became enthralled with liquid-fuel rockets and this amateur rocket group, the VfR, included Wernher von Braun, who became the head of the army research station that secretly built the V-2 rocket weapon for the Nazis. The German-Romanian Hermann Oberth published a book in 1922 suggesting the use of liquid propellants, after World War II the American government and military finally seriously considered liquid-propellant rockets as weapons and began to fund work on them. The Soviet Union did likewise, and thus began the Space Race, bipropellant liquid rockets generally use a liquid fuel, such as liquid hydrogen or a hydrocarbon fuel such as RP-1, and a liquid oxidizer, such as liquid oxygen. The engine may be a rocket engine, where the fuel and oxidizer
3.
Rocket engine
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A rocket engine is a type of jet engine that uses only stored rocket propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines, obtaining thrust in accordance with Newtons third law, most rocket engines are internal combustion engines, although non-combusting forms also exist. Vehicles propelled by rocket engines are commonly called rockets, since they need no external material to form their jet, rocket engines can perform in a vacuum and thus can be used to propel spacecraft and ballistic missiles. Compared to other types of jet engines, rocket engines have the highest thrust, are by far the lightest, the ideal exhaust is hydrogen, the lightest of all gases, but chemical rockets produce a mix of heavier species, reducing the exhaust velocity. Rocket engines become more efficient at high velocities, since they do not require an atmosphere, they are well suited for uses at very high altitude and in space. Here, rocket is used as an abbreviation for rocket engine, chemical rockets are powered by exothermic chemical reactions of the propellant. Thermal rockets use a propellant, heated by a power source such as electric or nuclear power. Solid-fuel rockets are chemical rockets which use propellant in a solid state, liquid-propellant rockets use one or more liquid propellants fed from tanks. Hybrid rockets use a propellant in the combustion chamber, to which a second liquid or gas oxidiser or propellant is added to permit combustion. Monopropellant rockets use a single propellant decomposed by a catalyst, the most common monopropellants are hydrazine and hydrogen peroxide. Rocket engines produce thrust by the expulsion of an exhaust fluid which has accelerated to a high speed through a propelling nozzle. The fluid is usually a gas created by high pressure combustion of solid or liquid propellants, consisting of fuel and oxidiser components, within a combustion chamber. The nozzle uses the energy released by expansion of the gas to accelerate the exhaust to very high speed. An alternative to combustion is the rocket, which uses water pressurised by compressed air, carbon dioxide, nitrogen, or manual pumping. Chemical rocket propellants are most commonly used, which undergo exothermic chemical reactions which produce hot gas which is used by a rocket for propulsive purposes. Alternatively, a chemically inert reaction mass can be heated using a power source via a heat exchanger. Solid rocket propellants are prepared as a mixture of fuel and oxidising components called grain, liquid-fuelled rockets force separate fuel and oxidiser components into the combustion chamber, where they mix and burn. Hybrid rocket engines use a combination of solid and liquid or gaseous propellants, both liquid and hybrid rockets use injectors to introduce the propellant into the chamber
4.
Anti-ship missile
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Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea skimming variety, and many use a combination of inertial guidance and active radar homing. A good number of other anti-ship missiles use infrared homing to follow the heat that is emitted by a ship, the first anti-ship missiles, which were developed and built by Nazi Germany, used radio command guidance. A variant of the HS293 had a TV transmitter on board, the bomber carrying it could then fly outside the range of naval AA guns and use TV guidance to lead the missile to its target by radio control. The term surface-to-surface missile is used when appropriate, the longer-range anti-ship missiles are often called anti-ship cruise missiles. A typical abbreviation for the phrase anti-ship missile is ASM, but AShM can also be used to avoid confusion with air-to-surface missiles, anti-submarine missiles, Anti-ship missiles were among the first instances of short-range guided missiles during World War II in 1943–44. These all used radio command-guidance from the bombardiers of the warplanes that launched them, some of these hit and either sank or damaged a number of ships, including warships offshore of amphibious landings on western Italy. These radio-controlled missiles were used successfully until the Allied navies developed missile countermeasures—principally radio jamming, the Allies also developed some of their own similar radio-guided AShMs, starting with the U. S. During the Cold War, the Soviet Union turned to a sea-denial strategy concentrating on submarines, naval mines, one of the first products of the decision was the SS-N-2 Styx missile. Further products were to follow, and they were loaded onto the Soviet Air Forces Tu-95 Bear and Tu-22 Blinder bombers. In 1967, the Israeli Navys destroyer Eilat was the first ship to be sunk by a ship-launched missile – a number of Styx missiles launched by Egyptian Komar-class missile boats off the Sinai Peninsula. In the Indo-Pakistani War of 1971 the Indian Navy conducted two raids using OSA 1-class missile boats employing the Styx on the Pakistani Naval base at Karachi and these raids resulted in the destruction or crippling of approximately two thirds of the Pakistani Navy. Major losses included two destroyers, an oiler, an ammunition ship, approximately a dozen merchant ships. Major shore based facilities, including fuel storage tanks and naval installations were also destroyed, the Osas returned to base without loss. The Battle of Latakia in 1973 was the scene of the worlds first combat between missile boats, in this battle, the Israeli Navy destroyed Syrian warships without suffering any damage, using electronic countermeasures and ruses for defense. Anti-ship missiles were used in the 1982 Falklands War, the British warship HMS Sheffield, a 4,820 ton Type 42 Destroyer, was struck by a single air-launched Exocet AShM, she later sank as a result of the damage that she sustained. The container ship Atlantic Conveyor was also sunk by an Exocet, in 1987, a US Navy guided-missile frigate, the USS Stark, was hit by an Exocet anti-ship missile fired by an Iraqi Mirage F-1 fighter plane. Stark was damaged, but she was able to steam to a port for temporary repairs
5.
Missile
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In modern language, a missile is a self-propelled precision-guided munition system, as opposed to an unguided self-propelled munition, referred to as a rocket. Missiles have four components, targeting and/or missile guidance, flight system, engine. Missiles come in types adapted for different purposes, surface-to-surface and air-to-surface missiles, surface-to-air missiles, air-to-air missiles, all known existing missiles are designed to be propelled during powered flight by chemical reactions inside a rocket engine, jet engine, or other type of engine. Non-self-propelled airborne explosive devices are referred to as shells and usually have a shorter range than missiles. In ordinary British-English usage predating guided weapons, a missile is any thrown object, the word missile comes from the Latin verb mittere, meaning to send. In military usage, munitions projected towards a target are broadly categorised as follows, a powered, unguided munition is known as a rocket. Unpowered munitions not fired from a gun are called bombs whether guided or not, munitions that are fired from a gun are known as projectiles whether guided or not. If explosive, they are more specifically as shells or mortar bombs. Powered munitions that travel through water are called torpedoes, hand grenades are not usually classed as missiles. The first missiles to be used operationally were a series of missiles developed by Nazi Germany in World War II, most famous of these are the V-1 flying bomb and V-2 rocket, both of which used a simple mechanical autopilot to keep the missile flying along a pre-chosen route. Less well known were a series of anti-shipping and anti-aircraft missiles, however, these early systems in World War II were only built in small numbers. Guided missiles have a number of different system components, Targeting and/or missile guidance Flight system Engine Warhead Missiles may be targeted in a number of ways. The most common method is to use some form of radiation, such as infrared, lasers or radio waves and this radiation may emanate from the target, it may be provided by the missile itself, or it may be provided by a friendly third party. The first two are known as fire-and-forget as they need no further support or control from the launch vehicle/platform in order to function. Another method is to use a TV guidance—using either visible light or infrared—in order to see the target, the picture may be used either by a human operator who steers the missile onto its target or by a computer doing much the same job. One of the more bizarre guidance methods instead used a pigeon to steer the missile to its target, many missiles use a combination of two or more of the above methods to improve accuracy and the chances of a successful engagement. Another method is to target the missile by knowing the location of the target and using a system such as INS. This guidance system guides the missile by knowing the current position and the position of the target
6.
Glide bomb
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A glide bomb or stand-off bomb is a standoff weapon with flight control surfaces to give it a flatter, gliding flight path than that of a conventional bomb without such surfaces. This allows it to be released at a distance from the rather than right over it. The term glide bombing does not refer to the use of glide bombs, guidance signals were to be transmitted through a thin copper wire, and guide flares were to be carried to help control. Siemens-Schuckertwerke was already occupied with remote controlled boats, and had experience in this area. The last test flight was performed on February 8,1918 and it was planned to use the Siemens-Schuckert R. VIII bomber as a carrier craft, but the Armistice stopped the project. During World War II the first operational glide bombs were developed by the Germans as an anti-shipping weapon. Ships are typically difficult to attack, a direct hit or an extremely near miss is needed to do any serious damage. At first dive bombers were used with success in this role. By 1941 accurate bombing was as difficult as ever, with the problem of evading anti-aircraft fire. The German solution was the development of a number of glide bombs employing radio control guidance and this weapon was designed specifically to pierce the deck armor of heavy cruisers and battleships. The bomb aimer dropped the bomb from high altitude while the aircraft was approaching the ship. This proved to be difficult to do, because as the bomb dropped toward the target it fell further behind the launch aircraft and this problem was solved by having the launch aircraft slow down and enter a climb to avoid overtaking the bomb as it fell. Nevertheless, the Fritz X proved useful with crews trained on its use, in test drops from 8,000 m, experienced bomb aimers could place half the bombs within a 15 m radius and 90% within 30 m. Design work started as early as 1939, and a version of the guidance package mounted to standard 500 kg bombs was tested in September 1940. It was found that the bomb was unable to penetrate a ships armor, following the capitulation of Italy in 1943, Germany damaged the Italian battleship Italia and sank the Roma with Fritz-X bombs. Attacks were also made on the USS Savannah, causing much damage, HMS Warspite was hit by three Fritz-X, and although casualties were few, the ship had to be towed to Malta for repairs and was out of action for six months. The cruiser USS Philadelphia was very slightly damaged by several near misses from Fritz-X bombs, the light cruiser HMS Uganda was also hit and put out of action for almost the entire war as a result. A more widely employed weapon was the Henschel Hs 293, which included wings and this weapon was designed for use against thinly armored but highly defended targets such as convoy merchantmen or their escorting warships
7.
Walter HWK 109-500
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The Walter HWK 109-500 was a liquid fuelled rocket motor developed by Walter in Germany during the Second World War. Modular monopropellant Starthilfe motor in a pod, able to produce 500 kg thrust for thirty seconds, after the fuel was expended, the pod was jettisoned and it returned to earth by parachute, with the parachute packed externally, onto the blunt forward end of the pod. It entered service in 1942, and some 6,000 were built, the Mill, Gloucestershire, History Press,2013. Type, liquid propellant rocket Length, Diameter, Dry weight,125 kg Compressor, Maximum thrust,500 kg Power-to-weight ratio, Christopher, the Mill, Gloucestershire, History Press,2013. Walterewrke. co. uk page on the HWK 109-500 Starthilfe rocket motor Video of HWK 109-500 Starthilfe-boosted Blohm & Voss Bv 138 flying boat takeoff
8.
JATO
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JATO, is a type of assisted take-off for helping overloaded aircraft into the air by providing additional thrust in the form of small rockets. The term JATO is used interchangeably with the term RATO, for rocket-assisted take-off, early experiments using rockets to boost gliders into the air were conducted in Germany in the 1920s, and later both the Royal Air Force and the Luftwaffe introduced such systems in World War II. After firing, the rocket was released from the back of the plane to fall into the water, the task done, the pilot would fly to friendly territory if possible or parachute from the plane, hopefully to be picked up by one of the escort vessels. Over two years the system was only employed nine times to attack German aircraft with eight kills recorded for the loss of a single pilot. The use of reaction-assisted takeoff methods became especially important late in the war when the lengths of usable runways were severely curtailed due to the results of Allied bombing. A parachute pack at the front of the motors exterior housing was used to slow its fall after being released from the plane. Two prototypes of the Heimatschützer versions of the Me 262 were built and test flown, in late 1941 von Kármán and his team attached several 50-pound thrust, solid fuel Aerojet JATOs to a light Ercoupe plane, and Army Captain Homer Boushey took off on test runs. On the last run they removed the propeller, attached six JATO units under the wings, and Boushey was thrust into the air for a short flight, both armed services used solid fuel JATO during the war. As the take-off thrust of jet engines has grown, JATO has fallen from favor and it is still used, however, when heavily-laden aircraft need to take off from short runways or when operating in Hot and high conditions. The US Air Force used a modified Republic F-84, designated EF-84G, the Soviet VVS used a modified MiG-19 fighter, designated SM-30, launched from a special launcher, and using a nearly identical solid-fueled rocket booster design to that of the EF-84G. The F-100 and F-104 were also used for zero-length launch experiments, the JATO Junior was an attempt by Aerojet Engineering to introduce smaller JATO units to small commercial aircraft, but was blocked by the U. S. Navy Bureau of Aeronautics. The Boeing 727 had provision for Aerojet JATO assist for use in hot, the JATO Rocket Car is an urban legend that relates the story of a car equipped with JATO units that is later found smashed into a mountainside. This story is given as an example of a Darwin Award, it appears to be apocryphal. The legend has been examined several times on the Discovery Channel show MythBusters, for the first attempt, in a 2003 pilot episode, the crew replicated the scene and the thrust of the JATO with some commercially available amateur rocket motors. The car did go very fast, outrunning the chase helicopter, but nowhere near the 300 mph reported in the original story, and failed to become airborne. The myth was revisited in 2007, using a different configuration of rockets in an attempt to make the car fly, the myth was again revisited in 2013 in the 1st Episode of Mythbusters Series 12 - as a celebration for the 10th year on air. A JATO-equipped 1958 Dodge Coronet car on the El Mirage dry lake was used for a TV advertisement to demonstrate the power of their total contact brakes and this was broadcast during The Lawrence Welk Show in the late 1950s. Notes Video of the Heinkel He 111 fitted with Walters rocket boosters Birth of JATO, popular Science, July 1946, pp. 74–75
9.
Turbopump
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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. The purpose of a turbopump is to produce a fluid for feeding a combustion chamber or other use. 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, turbopumps operate in much the same way as turbocharger units for vehicles, higher fuel pressures allow fuel to be supplied to higher-pressure combustion chambers for higher-performance engines. High-pressure pumps for larger missiles had been discussed by rocket pioneers such as Hermann Oberth, in mid-1935 Wernher von Braun initiated a fuel pump project at the southwest German firm Klein, Schanzlin & Becker that was experienced in building large fire-fighting pumps. The first engine fired successfully in September, and on August 16,1942, the first successful V-2 launch was on October 3,1942. The principal engineer for development at Aerojet was George Bosco. During the second half of 1947, Bosco and his group learned about the work of others. Aerojet representatives visited Ohio State University where Florant was working on hydrogen pumps, and consulted Dietrich Singelmann, Bosco subsequently used Singelmanns data in designing Aerojets first hydrogen pump. By mid-1948, Aerojet had selected centrifugal pumps for liquid hydrogen and liquid oxygen. They obtained some German radial-vane pumps from the Navy and tested them during the half of the year. By the end of 1948, Aerojet had designed, built, initially, it used ball bearings that were run clean and dry, because the low temperature made conventional lubrication impractical. The pump was first operated at low speeds to allow its parts to cool down to operating temperature, when temperature gauges showed that liquid hydrogen had reached the pump, an attempt was made to accelerate from 5000 to 35000 revolutions per minute. The pump failed and examination of the pieces pointed to a failure of the bearing, after some testing, super-precision bearings, lubricated by oil that was atomized and directed by a stream of gaseous nitrogen, were used. On the next run, the bearings worked satisfactorily but the stresses were too great for the brazed impeller, a new one was made by milling from a solid block of aluminum. The next two runs with the new pump were a disappointment, the instruments showed no significant flow or pressure rise. The problem was traced to the diffuser of the pump. This was corrected by adding vent holes in the pump housing, with this fix, two additional runs were made in March 1949 and both were successful
10.
Combustion chamber
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A combustion chamber is that part of an internal combustion engine in which the fuel/air mix is burned. ICEs typically comprise reciprocating piston engines, rotary engines, gas turbines, the combustion process increases the internal energy of a gas, which translates into an increase in temperature, pressure, or volume depending on the configuration. In an enclosure, for example the cylinder of an engine, the volume is controlled. In a continuous system, for example a jet engine combustor, the pressure is controlled. This increase in pressure or volume can be used to do work, for example, if the gas velocity changes, thrust is produced, such as in the nozzle of a rocket engine. At top dead centre the pistons of an engine are flush with the top of the cylinder block. The combustion chamber may be a recess either in the cylinder head, a design with the combustion chamber in the piston is called a Heron head, where the head is machined flat but the pistons are dished. The Heron head has proved even more efficient than the hemispherical head. Intake valves permit the inflow of a fuel air mix, and this is best achieved with a compact rather than elongated chamber. Swirl & Squish The intake valve/port is usually placed to give the mixture a pronounced swirl above the piston, improving mixing. The shape of the top also affects the amount of swirl. Another design feature to promote turbulence for good fuel/air mixing is squish, where swirl is particularly important, combustion chambers in the piston may be favoured. Flame front Ignition typically occurs around 15 degrees before top dead centre, the spark plug must be sited so that the flame front can progress throughout the combustion chamber. Harry Ricardo was prominent in developing combustion chambers for diesel engines, the combustion chamber in gas turbines and jet engines is called the combustor. Different types of combustors exist, mainly, Can type, Can combustors are self-contained cylindrical combustion chambers, each can has its own fuel injector, liner, interconnectors, casing. Each can get an air source from individual opening, cannular type, Like the can type combustor, can annular combustors have discrete combustion zones contained in separate liners with their own fuel injectors. Unlike the can combustor, all the combustion zones share a common air casing, Annular type, Annular combustors do away with the separate combustion zones and simply have a continuous liner and casing in a ring. The term combustion chamber is used to refer to an additional space between the firebox and boiler in a steam locomotive
11.
Carbon steel
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The term carbon steel may also be used in reference to steel which is not stainless steel, in this use carbon steel may include alloy steels. As the carbon percentage content rises, steel has the ability to become harder and stronger through heat treating, however, regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the carbon content lowers the melting point. Mild steel, also known as steel and Low carbon steel. It is now the most common form of steel because its price is relatively low while it provides material properties that are acceptable for many applications, mild steel contains approximately 0. 05–0. 25% carbon making it malleable and ductile. Mild steel has a low tensile strength, but it is cheap and easy to form. It is often used large quantities of steel are needed. The density of steel is approximately 7.85 g/cm3. Low-carbon steels suffer from yield-point runout where the material has two yield points, the first yield point is higher than the second and the yield drops dramatically after the upper yield point. If a low-carbon steel is only stressed to some point between the upper and lower yield point then the surface develop Lüder bands, low-carbon steels contain less carbon than other steels and are easier to cold-form, making them easier to handle. Carbon steels which can successfully undergo heat-treatment have a content in the range of 0. 30–1. 70% by weight. Trace impurities of other elements can have a significant effect on the quality of the resulting steel. Trace amounts of sulfur in particular make the steel red-short, that is, brittle, low-alloy carbon steel, such as A36 grade, contains about 0. 05% sulfur and melts around 1, 426–1,538 °C. Manganese is often added to improve the hardenability of low-carbon steels and these additions turn the material into a low-alloy steel by some definitions, but AISIs definition of carbon steel allows up to 1. 65% manganese by weight. Carbon steel is broken down into four classes based on content,0.05 to 0. 25% carbon content. Balances ductility and strength and has good resistance, used for large parts, forging. Very strong, used for springs, swords, and high-strength wires, steels that can be tempered to great hardness. Used for special purposes like knives, axles or punches, most steels with more than 2. 5% carbon content are made using powder metallurgy
12.
Refractory metal
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Refractory metals are a class of metals that are extraordinarily resistant to heat and wear. The expression is used in the context of materials science, metallurgy. The definition of which belong to this group differs. The most common definition includes five elements, two of the period and three of the sixth period. They all share some properties, including a point above 2000 °C. They are chemically inert and have a high density. Their high melting points make powder metallurgy the method of choice for fabricating components from these metals, some of their applications include tools to work metals at high temperatures, wire filaments, casting molds, and chemical reaction vessels in corrosive environments. Partly due to the melting point, refractory metals are stable against creep deformation to very high temperatures. Most definitions of the refractory metals list the extraordinarily high melting point as a key requirement for inclusion. By one definition, a point above 4,000 °F is necessary to qualify. The melting point of the metals are the highest for all elements except carbon. This high melting point defines most of their applications, all the metals are body-centered cubic except rhenium which is hexagonal close-packed. Most physical properties of the elements in this group vary significantly because they are members of different groups, creep resistance is a key property of the refractory metals. This resistance against deformation at high temperatures makes the refractory metals suitable against strong forces at high temperature, for example in jet engines, the refractory metals show a wide variety of chemical properties because they are members of three distinct groups in the periodic table. They are easily oxidized, but this reaction is slowed down in the metal by the formation of stable oxide layers on the surface. Especially the oxide of rhenium is more volatile than the metal and they all are relatively stable against acids. Refractory metals are used in lighting, tools, lubricants, nuclear control rods, as catalysts. Because of their melting point, refractory metal components are never fabricated by casting
13.
Calcium permanganate
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Calcium permanganate is an oxidizing agent and chemical compound with the chemical formula Ca2. It consists of the calcium and two permanganate ions. It is noncombustible, but, being a strong oxidizing agent, if the combustible material is finely divided, the resulting mixture may be explosive. Contact with liquid combustible materials may result in spontaneous ignition, contact with sulfuric acid may cause fires or explosions. Mixtures with acetic acid or acetic anhydride can explode if not kept cold, explosions can occur when mixtures of calcium permanganate and sulfuric acid come into contact with benzene, carbon disulfide, diethyl ether, ethyl alcohol, petroleum, or other organic matter. It is prepared from the reaction of potassium permanganate with calcium chloride or from the reaction of aluminum permanganate with calcium oxide and it is believed to help whiten teeth. Potassium permanganate Sodium permanganate Ammonium permanganate
14.
Bar (unit)
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The bar is a metric unit of pressure, but is not approved as part of the International System of Units. It is defined as equal to 100000 Pa, which is slightly less than the current average atmospheric pressure on Earth at sea level. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, use of the bar is deprecated by some professional bodies in some fields. The International Astronomical Union also lists it under Non-SI units and symbols whose continued use is deprecated, as of 2004, the bar is legally recognized in countries of the European Union. Units derived from the bar include the megabar, kilobar, decibar, centibar, the notation bar, though deprecated by various bodies, represents gauge pressure, i. e. pressure in bars above ambient or atmospheric pressure. The bar is defined using the SI derived unit, pascal,1 bar ≡100000 Pa. Thus,1 bar is equal to,100 kPa 1×105 N/m21000000 Ba, notes,1 millibar =1 one-thousandth bar, or 1×10−3 bar 1 millibar =1 hectopascal. The word bar has its origin in the Greek word βάρος, the units official symbol is bar, the earlier symbol b is now deprecated and conflicts with the use of b denoting the unit barn, but it is still encountered, especially as mb to denote the millibar. Between 1793 and 1795, the bar was used for a unit of weight in an early version of the metric system. Atmospheric air pressure is given in millibars where standard sea level pressure is defined as 1013 mbar,101.3,1.013 bar. Despite the millibar not being an SI unit, meteorologists and weather reporters worldwide have long measured air pressure in millibars as the values are convenient, for example, the weather office of Environment Canada uses kilopascals and hectopascals on their weather maps. In contrast, Americans are familiar with the use of the millibar in US reports of hurricanes, in fresh water, there is an approximate numerical equivalence between the change in pressure in decibars and the change in depth from the water surface in metres. Specifically, an increase of 1 decibar occurs for every 1.019716 m increase in depth, in sea water with respect to the gravity variation, the latitude and the geopotential anomaly the pressure can be converted into meters depth according to an empirical formula. As a result, decibars are commonly used in oceanography, many engineers worldwide use the bar as a unit of pressure because, in much of their work, using pascals would involve using very large numbers. In the automotive field, turbocharger boost is often described in bars outside the USA), unicode has characters for mb and bar, but they exist only for compatibility with legacy Asian encodings and are not intended to be used in new documents. The kilobar, equivalent to 100 MPa, is used in geological systems. Bar and bara are sometimes used to indicate absolute pressures and bar and this usage is deprecated and fuller descriptions such as gauge pressure of 2 bar or 2 bar gauge are recommended.0 Unported License but not under the GFDL. Non-SI units accepted for use with the SI
15.
Pounds per square inch
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The pound per square inch or, more accurately, pound-force per square inch is a unit of pressure or of stress based on avoirdupois units. Now converting the psi to standard atmospheres,1 atm =101325 Pa =101325 Pa 6894.757293168 Pa / psi ≈14.70 psi Therefore,1 atmosphere is approximately 14.7 pounds per square inch. Pounds per square inch absolute is used to make it clear that the pressure is relative to a rather than the ambient atmospheric pressure. Since atmospheric pressure at sea level is around 14.7 psi, the converse is pounds per square inch gauge or pounds per square inch gage, indicating that the pressure is relative to atmospheric pressure. For example, a bicycle tire pumped up to 65 psi above atmospheric pressure. When gauge pressure is referenced to something other than ambient atmospheric pressure, the kilopound per square inch is a scaled unit derived from psi, equivalent to a thousand psi. Ksi are not widely used for gas pressures and they are mostly used in materials science, where the tensile strength of a material is measured as a large number of psi. The conversion in SI Units is 1 ksi =6.895 MPa, the megapound per square inch is another multiple equal to a million psi. It is used in mechanics for the modulus of the materials. The conversion in SI Units is 1 Mpsi =6.895 GPa, inch of water,0.036 psid Blood pressure – clinically normal human blood pressure,2.32 psig/1.55 psig Natural gas residential piped in for consumer appliance, 4–6 psig. Boost pressure provided by a turbocharger, 6–15 psig NFL football,12. 5–13.5 psig Atmospheric pressure at sea level,14
16.
Aluminium alloy
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Aluminium alloys are alloys in which aluminium is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, there are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. About 85% of aluminium is used for products, for example rolled plate, foils. Cast aluminium alloys yield cost-effective products due to the low melting point, the most important cast aluminium alloy system is Al–Si, where the high levels of silicon contribute to give good casting characteristics. Aluminium alloys are used in engineering structures and components where light weight or corrosion resistance is required. Alloys composed mostly of aluminium have been important in aerospace manufacturing since the introduction of metal-skinned aircraft. Aluminium-magnesium alloys are both lighter than aluminium alloys and much less flammable than alloys that contain a very high percentage of magnesium. Aluminium alloy surfaces will develop a white, protective layer of aluminium oxide if left unprotected by anodizing and/or correct painting procedures, referred to as dissimilar-metal corrosion, this process can occur as exfoliation or as intergranular corrosion. Aluminium alloys can be heat treated. This causes internal element separation, and the metal then corrodes from the inside out, Aluminium alloy compositions are registered with The Aluminum Association. Aluminium alloys with a range of properties are used in engineering structures. Alloy systems are classified by a system or by names indicating their main alloying constituents. Selecting the right alloy for a given application entails considerations of its strength, density, ductility, formability, workability, weldability. A brief historical overview of alloys and manufacturing technologies is given in Ref. Aluminium alloys are used extensively in aircraft due to their high strength-to-weight ratio. On the other hand, pure aluminium metal is too soft for such uses. Aluminium alloys typically have an elastic modulus of about 70 GPa, therefore, for a given load, a component or unit made of an aluminium alloy will experience a greater deformation in the elastic regime than a steel part of identical size and shape. Though there are aluminium alloys with somewhat-higher tensile strengths than the commonly used kinds of steel, with completely new metal products, the design choices are often governed by the choice of manufacturing technology. Extrusions are particularly important in regard, owing to the ease with which aluminium alloys, particularly the Al–Mg–Si series
17.
Fritz X
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Fritz X was the most common name for a German guided anti-ship glide bomb used during World War II. Fritz X was the worlds first precision guided weapon deployed in combat, Fritz X was a nickname used both by Allied and Luftwaffe personnel. Alternative names include Ruhrstahl SD1400 X, Kramer X-1, PC 1400X or FX1400, along with the USAAFs similar Azon weapon of the same period in World War II, it is one of the precursors of todays anti-ship missiles and precision-guided weapons. The Fritz X was a development of the PC1400 armour-piercing high-explosive bomb. It was a weapon intended to be used against heavily protected targets such as heavy cruisers. The Luftwaffe recognized the difficulty of hitting moving ships during the Spanish Civil War, engineer Max Kramer, who worked at the DVL, had been experimenting since 1938 with remote-controlled free-falling 250 kg bombs, and in 1939 fitted radio-controlled spoilers. In 1940, Ruhrstahl was invited to join the development, since they already had experience in the development and production of unguided bombs. Fritz X was guided by a Kehl-Strasbourg radio control link, which sent signals to the spoilers in the thick vertical and horizontal tail fin surfaces. This control system was used for the unarmored, rocket-boosted Henschel Hs 293 anti-ship ordnance. Minimum launch height was 4,000 m and a range of 5 km was necessary. As it was an MCLOS-guidance ordnance design, the operator had to keep the bomb in sight at all times and the aircraft had to hold course. Approximately 1400 examples, including models, were produced. The yaw control spoilers housed in the vertical surfaces were also under control through the radio link. Fritz-X was steered by the bombardier in the aircraft over a radio link between the aircrafts Kehl transmitter and the weapons Straßburg receiver. The disadvantage with this — in comparison to fully autonomous-guidance glide bombs like the operational U. S, unlike the Hs 293, which was deployed against merchant ships and light escorting warships, Fritz X was intended to be used against armoured ships such as heavy cruisers and battleships. The minimum release height was 4,000 metres and a height of 5,500 metres was preferred assuming adequate visibility. The Fritz X had to be released at least 5 kilometres from the target, the plane had to decelerate upon bomb release so momentum would carry the bomb in front of the aircraft where the bombardier could see and guide it. This deceleration was achieved by making a steep climb and then levelling out, the bombardier could make a maximum correction of 500 metres in range and 350 metres in bearing
18.
Capital ship
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The capital ships of a navy are its most important warships, they are generally the larger ships when compared to other warships in their respective fleet. A capital ship is generally a leading or a ship in a naval fleet. William S. Lind, in the book America Can Win, defines a capital ship as follows, These characteristics define a capital ship, if the ships are beaten. But if the rest of the navy is beaten, the ships can still operate. Another characteristic that defines capital ships is that their opponent is each other. The Mahanian doctrine was applied by the Imperial Japanese Navy, leading to its preventive move to attack Pearl Harbor. Four-deckers suffered in rough seas, and the lowest deck could seldom fire except in calm conditions, third rate,64 to 80 guns. Fourth rate,46 to 60 guns, frigates were ships of the fifth rate, sixth rates comprised small frigates and corvettes. Towards the end of the Napoleonic Wars and into the late 19th century, some larger and this applied mainly to ships resulting from the dreadnought revolution, dreadnought battleships and battlecruisers. In the 20th century, especially in World Wars I and II, typical capital ships would be battleships, all of the above ships were close to 20,000 tons displacement or heavier, with large caliber guns and heavy armor protection. Heavy cruisers, despite being important ships, were not considered capital ships, an exception to the above in World War II was the Deutschland-class cruiser. The Alaska-class cruisers, despite being oversized heavy cruisers and not true battleships/battlecruisers, were considered by some to be capital ships. In regard to design, however, the Kirov is simply a supersized guided-missile cruiser with nuclear propulsion. It took until late 1942 for aircraft carriers to be considered capital ships. The U. S. Navy was forced to rely primarily on its aircraft carriers after the attack on Pearl Harbor sank or damaged eight of its Pacific-fleet battleships. In the 21st century, the carrier is the last remaining capital ship, with capability defined in decks available and aircraft per deck, rather than in guns. Despite their significance to modern fleets, the U. S. Navy has never named aircraft carriers after U. S. states as was the practice when battleships were considered capital ships. Instead, U. S. state names are applied to nuclear submarines while Aircraft Carriers are named after famous Navy personel and presidents, such as Chester W. Nimitz
19.
Kerosene
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Kerosene, also known as paraffin, lamp oil and coal oil, is a combustible hydrocarbon liquid which is derived from petroleum, widely used as a fuel in industry as well as households. Its name derives from Greek, κηρός meaning wax, and was registered as a trademark by Abraham Gesner in 1854 before evolving into a genericized trademark and it is sometimes spelled kerosine in scientific and industrial usage. Liquid paraffin is a more viscous and highly refined product which is used as a laxative, paraffin wax is a waxy solid extracted from petroleum. Kerosene is widely used to power jet engines of aircraft and some rocket engines, in parts of Asia, where the price of kerosene is subsidized, it fuels outboard motors on small fishing boats. World total kerosene consumption for all purposes is equivalent to about 1.2 million barrels per day, to prevent confusion between kerosene and the much more flammable and volatile gasoline, some jurisdictions regulate markings or colorings for containers used to store or dispense kerosene. For example, in the United States, the Commonwealth of Pennsylvania requires that portable containers used at retail service stations be colored blue and it is miscible in petroleum solvents but immiscible in water. The American Society for Testing and Materials standard specification D-3699-78 recognizes two grades of kerosene, grades 1-K and 2-K, regardless of crude oil source or processing history, kerosenes major components are branched and straight chain alkanes and naphthenes, which normally account for at least 70% by volume. Aromatic hydrocarbons in this range, such as alkylbenzenes and alkylnaphthalenes. Olefins are usually not present at more than 5% by volume, the flash point of kerosene is between 37 and 65 °C, and its autoignition temperature is 220 °C. The pour point of kerosene depends on grade, with aviation fuel standardized at −47 °C. 1-K grade kerosene freezes around -40 °C, heat of combustion of kerosene is similar to that of diesel fuel, its lower heating value is 43.1 MJ/kg, and its higher heating value is 46.2 MJ/kg. In the United Kingdom, two grades of heating oil are defined, BS2869 Class C1 is the lightest grade used for lanterns, camping stoves, wick heaters, and mixed with gasoline in some vintage combustion engines as a substitute for tractor vaporising oil. BS2869 Class C2 is a heavier distillate, which is used as heating oil. Premium kerosene is sold in 5 or 20 liter containers from hardware, camping. Standard kerosene is usually dispensed in bulk by a tanker and is undyed, National and international standards define the properties of several grades of kerosene used for jet fuel. Flash point and freezing point properties are of particular interest for operation and safety, the process of distilling crude oil/petroleum into kerosene, as well as other hydrocarbon compounds, was first written about in the 9th century by the Persian scholar Rāzi. In his Kitab al-Asrar, the physician and chemist Razi described two methods for the production of kerosene, termed naft abyad, using an apparatus called an alembic, one method used clay as an absorbent, whereas the other method used ammonium chloride. The distillation process was repeated until all most of the volatile hydrocarbon fractions had been removed, Kerosene was also produced during the same period from oil shale and bitumen by heating the rock to extract the oil, which was then distilled
20.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
21.
Aircraft engine
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An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines, in commercial aviation, the major players in the manufacturing of turbofan engines are Pratt & Whitney, General Electric, Rolls-Royce, and CFM International. In general aviation, the dominant manufacturer of engines has been Pratt & Whitney. General Electric announced in 2015 entrance into the market,1848, John Stringfellow made a steam engine for a 10-foot wingspan model aircraft which achieved the first powered flight, albeit with negligible payload. 1903, Charlie Taylor built an inline aeroengine for the Wright Flyer,1903, Manly-Balzer engine sets standards for later radial engines. 1906, Léon Levavasseur produces a successful water-cooled V8 engine for aircraft use,1908, René Lorin patents a design for the ramjet engine. 1908, Louis Seguin designed the Gnome Omega, the worlds first rotary engine to be produced in quantity. In 1909 a Gnome powered Farman III aircraft won the prize for the greatest non-stop distance flown at the Reims Grande Semaine dAviation setting a record for endurance of 180 kilometres. 1910, Coandă-1910, a ducted fan aircraft exhibited at Paris Aero Salon. The aircraft never flew, but a patent was filed for routing exhaust gases into the duct to augment thrust,1930, Frank Whittle submitted his first patent for turbojet engine. June 1939, Heinkel He 176 is the first successful aircraft to fly powered solely by a rocket engine. August 1939, Heinkel HeS3 turbojet propels the pioneering German Heinkel He 178 aircraft,1940, Jendrassik Cs-1, the worlds first run of a turboprop engine. It is not put into service,1943 Daimler-Benz DB670, first turbofan runs 1944, Messerschmitt Me 163B Komet, the worlds first rocket-propelled combat aircraft deployed. 1945, First turboprop powered aircraft flies, a Gloster Meteor with two Rolls-Royce Trent engines,1947, Bell X-1 rocket propelled aircraft exceeds the speed of sound. 1948,100 shp 782, the first turboshaft engine to be applied to aircraft use,1949, Leduc 010, the worlds first ramjet-powered aircraft flight. 1950, Rolls-Royce Conway, the worlds first production turbofan, enters service,1968, General Electric TF39 high bypass turbofan enters service delivering greater thrust and much better efficiency. 2002, HyShot scramjet flew in dive,2004, NASA X-43, the first scramjet to maintain altitude. This is typically to differentiate them from radial engines, a straight engine typically has an even number of cylinders, but there are instances of three- and five-cylinder engines
22.
Walter HWK 509
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The Walter HWK 109-509 was a German liquid-fuel bipropellant rocket engine that powered the Messerschmitt Me 163 Komet and Bachem Ba 349 aircraft. It was produced by Hellmuth Walter Kommanditgesellschaft commencing in 1943, early versions of the Me 163 had been powered by an earlier design running on a cold engine fueled with Z-Stoff. This fuel tended to clog the jets in the chamber, causing fluctuations in power. The RLM demanded that a version be developed with a throttle, during this period Walter has also been working with a new fuel known as C-Stoff that gave off significant heat and was thus known as the hot engine. C-Stoff was a mix of 30% hydrazine hydrate + 57% methanol + 13% water with an amount of potassium-copper-cyanide. The oxidizer, known as T-Stoff, consisted of a hydrogen peroxide-based formulation, the two reacted violently on contact. To address the issue, the new engine included turbopumps with two settings. The pumps were driven by a turbine, powered by steam created by decomposing the T-Stoff with a wire mesh catalyst. Combined with a throttle, this provided four power settings from idle to full power for climbing. In practice it was found that throttling the engine dramatically decreased its fuel economy to the point that it did not extend the endurance of the aircraft as expected and this version was put into the Me 163B in spite of this problem. The ultimate solution to the problem was the B and C series of the engine. This chamber provided that power at peak efficiency, so it did not suffer from the problems found while throttling on the original models, the throttle on the original combustion chamber was removed, and throttling was instead provided by turning the main engine on and off. This new version dramatically improved cruise endurance, with flight times improving from eight to twelve minutes. It was also mechanically simpler as the turbopumps were no longer throttled, the engine was an integral design with all components of the drive, with the exception of fuel tanks, locked in a cubical frame — this frame was discarded for the 109-509C dual-chamber design. 509 A-0, Pre-production model, manufactured from May 1943, the thrust of this engine was regulated between 300 kp and 1500 kp.509 A-1, The first series production engine was used in the Messerschmitt Me 163 B from August 1944. The thrust here was adjustable between 100 kp and 1600 kp.509 A-2, Version for the Messerschmitt Me 163B-1a, the thrust was adjustable between 200 kp and a maximum of 1700 kp.509 B-1, Increased performance version of the 509 A-1. This auxiliary chamber proved necessary due to the actual T-Stoff oxidizer consumption of the unit, at nearly 5 kg/s. The main combustion chamber gave between 400 kp and 2000 kp, the Marschofen auxiliary chamber 400 kp, to be used in the Me 263
