1.
Turbocharger
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Turbochargers were originally known as turbosuperchargers when all forced induction devices were classified as superchargers. Nowadays the term supercharger is usually applied only to mechanically driven forced induction devices, compared to a mechanically driven supercharger, turbochargers tend to be more efficient, but less responsive. Twincharger refers to an engine with both a supercharger and a turbocharger, turbochargers are commonly used on truck, car, train, aircraft, and construction equipment engines. They are most often used with Otto cycle and Diesel cycle internal combustion engines and they have also been found useful in automotive fuel cells. Forced induction dates from the late 19th century, when Gottlieb Daimler patented the technique of using a pump to force air into an internal combustion engine in 1885. During World War I French engineer Auguste Rateau fitted turbochargers to Renault engines powering various French fighters with some success, in 1918, General Electric engineer Sanford Alexander Moss attached a turbocharger to a V12 Liberty aircraft engine. Turbochargers were first used in aircraft engines such as the Napier Lioness in the 1920s. Ships and locomotives equipped with turbocharged diesel engines began appearing in the 1920s, turbochargers were also used in aviation, most widely used by the United States. During World War II, notable examples of U. S. aircraft with turbochargers include the B-17 Flying Fortress, B-24 Liberator, P-38 Lightning, and P-47 Thunderbolt. Turbochargers are widely used in car and commercial vehicles because they allow smaller-capacity engines to have improved fuel economy, reduced emissions, higher power, in contrast to turbochargers, superchargers are mechanically driven by the engine. Belts, chains, shafts, and gears are common methods of powering a supercharger, for example, on the single-stage single-speed supercharged Rolls-Royce Merlin engine, the supercharger uses about 150 horsepower. Yet the benefits outweigh the costs, for the 150 hp to drive the supercharger the engine generates an additional 400-horsepower, a net gain of 250 hp. This is where the principal disadvantage of a supercharger becomes apparent, another disadvantage of some superchargers is lower adiabatic efficiency as compared to turbochargers. Adiabatic efficiency is a measure of an ability to compress air without adding excess heat to that air. Even under ideal conditions, the compression process always results in elevated temperature, however. Roots superchargers impart significantly more heat to the air than turbochargers, thus, for a given volume and pressure of air, the turbocharged air is cooler, and as a result denser, containing more oxygen molecules, and therefore more potential power than the supercharged air. In practical application the disparity between the two can be dramatic, with turbochargers often producing 15% to 30% more power based solely on the differences in adiabatic efficiency. By comparison, a turbocharger does not place a direct mechanical load on the engine, although turbochargers place exhaust back pressure on engines, in contrast to supercharging, the primary disadvantage of turbocharging is what is referred to as lag or spool time
2.
Supercharger
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A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine. This gives each intake cycle of the more oxygen, letting it burn more fuel and do more work. Power for the supercharger can be provided mechanically by means of a belt, gear, shaft, when power is provided by a turbine powered by exhaust gas, a supercharger is known as a turbosupercharger – typically referred to simply as a turbocharger or just turbo. Common usage restricts the term supercharger to mechanically driven units, in 1848 or 1849 G. Jones of Birmingham, England brought out a Roots-style compressor. The worlds first functional, actually tested engine supercharger was made by Dugald Clerk, gottlieb Daimler received a German patent for supercharging an internal combustion engine in 1885. Louis Renault patented a centrifugal supercharger in France in 1902, an early supercharged race car was built by Lee Chadwick of Pottstown, Pennsylvania in 1908 which reportedly reached a speed of 100 mph. The worlds first series-produced cars with superchargers were Mercedes 6/25/40 hp, both models were introduced in 1921 and had Roots superchargers. They were distinguished as Kompressor models, the origin of the Mercedes-Benz badging which continues today, on March 24,1878 Heinrich Krigar of Germany obtained patent #4121, patenting the first ever screw-type compressor. Later that same year on August 16 he obtained patent #7116 after modifying and improving his original designs and his designs show a two-lobe rotor assembly with each rotor having the same shape as the other. Although the design resembled the Roots style compressor, the screws were clearly shown with 180 degrees of twist along their length, unfortunately, the technology of the time was not sufficient to produce such a unit, and Heinrich made no further progress with the screw compressor. Nearly half a century later, in 1935, Alf Lysholm and he also patented the method for machining the compressor rotors. There are two types of superchargers defined according to the method of gas transfer, positive displacement. Positive displacement blowers and compressors deliver an almost constant level of pressure increase at all engine speeds, dynamic compressors do not deliver pressure at low speeds, above a threshold speed, pressure increases with engine speed. Positive-displacement pumps deliver a nearly fixed volume of air per revolution at all speeds, Roots superchargers are external compression only. External compression refers to pumps that transfer air at ambient pressure into the engine, if the engine is running under boost conditions, the pressure in the intake manifold is higher than that coming from the supercharger. That causes a backflow from the engine into the supercharger until the two reach equilibrium and it is the backflow that actually compresses the incoming gas. This is an inefficient process and the factor in the lack of efficiency of Roots superchargers when used at high boost levels. The lower the boost level the smaller is this loss, and Roots blowers are very efficient at moving air at low pressure differentials, all the other types have some degree of internal compression
3.
Gas turbine
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A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a turbine. The basic operation of the gas turbine is similar to that of the power plant except that the working fluid is air instead of water. Fresh atmospheric air flows through a compressor that brings it to higher pressure, energy is then added by spraying fuel into the air and igniting it so the combustion generates a high-temperature flow. This high-temperature high-pressure gas enters a turbine, where it expands down to the exhaust pressure, the turbine shaft work is used to drive the compressor and other devices such as an electric generator that may be coupled to the shaft. The energy that is not used for shaft work comes out in the exhaust gases, the purpose of the gas turbine determines the design so that the most desirable energy form is maximized. Gas turbines are used to power aircraft, trains, ships, electrical generators,50, Heros Engine — Apparently, Heros steam engine was taken to be no more than a toy, and thus its full potential not realized for centuries. 1000, The Trotting Horse Lamp was used by the Chinese at lantern fairs as early as the Northern Song dynasty. When the lamp is lit, the heated airflow rises and drives an impeller with horse-riding figures attached on it,1629, Jets of steam rotated an impulse turbine that then drove a working stamping mill by means of a bevel gear, developed by Giovanni Branca. 1678, Ferdinand Verbiest built a model carriage relying on a jet for power. 1791, A patent was given to John Barber, an Englishman and his invention had most of the elements present in the modern day gas turbines. The turbine was designed to power a horseless carriage,1861, British patent no.1633 was granted to Marc Antoine Francois Mennons for a Caloric engine. The patent shows that it was a gas turbine and the show it applied to a locomotive. Also named in the patent was Nicolas de Telescheff, a Russian aviation pioneer,1872, A gas turbine engine was designed by Franz Stolze, but the engine never ran under its own power. 1894, Sir Charles Parsons patented the idea of propelling a ship with a turbine, and built a demonstration vessel. This principle of propulsion is still of some use,1895, Three 4-ton 100 kW Parsons radial flow generators were installed in Cambridge Power Station, and used to power the first electric street lighting scheme in the city. 1899, Charles Gordon Curtis patented the first gas engine in the USA. 1900, Sanford Alexander Moss submitted a thesis on gas turbines, in 1903, Moss became an engineer for General Electrics Steam Turbine Department in Lynn, Massachusetts
4.
Centrifugal pump
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Centrifugal pumps are a sub-class of dynamic axisymmetric work-absorbing turbomachinery. Centrifugal pumps are used to transport fluids by the conversion of kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor, the fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber, from where it exits. Common uses include water, sewage, petroleum and petrochemical pumping, the reverse function of the centrifugal pump is a water turbine converting potential energy of water pressure into mechanical rotational energy. True centrifugal pumps were not developed until the late 17th century, the curved vane was introduced by British inventor John Appold in 1851. Like most pumps, a centrifugal pump converts rotational energy, often from a motor, a portion of the energy goes into kinetic energy of the fluid. The fluid gains both velocity and pressure while passing through the impeller, the doughnut-shaped diffuser, or scroll, section of the casing decelerates the flow and further increases the pressure. A consequence of Newton’s second law of mechanics is the conservation of the momentum which is of fundamental significance to all turbomachines. Accordingly, the change of the momentum is equal to the sum of the external moments. Angular momentums ρ×Q×r×cu at inlet and outlet, an external torque M and this is an important role in old academic, this rule was helpful to detail Eq. become Eq. and wide explained how the pump works. Fig 2.3 shows triangle velocity of forward curved vanes impeller and it illustrates rather clearly energy added to the flow inversely change upon flow rate Q. Power is more commonly expressed as kilowatts or horsepower, the value for the pump efficiency, η p u m p, may be stated for the pump itself or as a combined efficiency of the pump and motor system. Vertical centrifugal pumps are also referred to as cantilever pumps and they utilize a unique shaft and bearing support configuration that allows the volute to hang in the sump while the bearings are outside the sump. This style of pump uses no stuffing box to seal the shaft, a common application for this style of pump is in a parts washer. In the mineral industry, or in the extraction of oilsand, froth is generated to separate the rich minerals or bitumen from the sand, froth contains air that tends to block conventional pumps and cause loss of prime. Over history, industry has developed different ways to deal with this problem, in the pulp and paper industry holes are drilled in the impeller. Air escapes to the back of the impeller and a special expeller discharges the air back to the suction tank, the impeller may also feature special small vanes between the primary vanes called split vanes or secondary vanes. Some pumps may feature an eye, an inducer or recirculation of pressurized froth from the pump discharge back to the suction to break the bubbles
5.
V-2 rocket
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The V-2, technical name Aggregat 4, was the worlds first long-range guided ballistic missile. The V-2 rocket also became the first artificial object to cross the boundary of space with the launch of MW18014 on 20 June 1944. Research into military use of long range rockets began when the studies of graduate student Wernher von Braun attracted the attention of the German Army, a series of prototypes culminated in the A-4, which went to war as the V-2. Beginning in September 1944, over 3,000 V-2s were launched by the German Wehrmacht against Allied targets during the war, first London and later Antwerp and Liège. As Germany collapsed, teams from the Allied forces—the United States, the United Kingdom, Wernher von Braun and over 100 key V-2 personnel surrendered to the Americans. Eventually, many of the original V-2 team ended up working at the Redstone Arsenal, the US also captured enough V-2 hardware to build approximately 80 of the missiles. The Soviets gained possession of the V-2 manufacturing facilities after the war, re-established V-2 production, in the late 1920s, a young Wernher von Braun bought a copy of Hermann Oberths book, Die Rakete zu den Planetenräumen. Starting in 1930, he attended the Technical University of Berlin, von Braun was working on his doctorate when the Nazi Party gained power in Germany. An artillery captain, Walter Dornberger, arranged an Ordnance Department research grant for von Braun, von Brauns thesis, Construction, Theoretical, and Experimental Solution to the Problem of the Liquid Propellant Rocket, was kept classified by the German Army and was not published until 1960. By the end of 1934, his group had launched two rockets that reached heights of 2.2 and 3.5 km. At the time, Germany was highly interested in American physicist Robert H. Goddards research, before 1939, German engineers and scientists occasionally contacted Goddard directly with technical questions. Von Braun used Goddards plans from various journals and incorporated them into the building of the Aggregat series of rockets, during 28–30 September 1939, Der Tag der Weisheit conference met at Peenemünde to initiate the funding of university research to solve rocket problems. By late 1941, the Army Research Center at Peenemünde possessed the essential to the success of the A-4. The four key technologies for the A-4 were large liquid-fuel rocket engines, supersonic aerodynamics, gyroscopic guidance, at the time, Adolf Hitler was not particularly impressed by the V-2, he pointed out that it was merely an artillery shell with a longer range and much higher cost. Hitler was sufficiently impressed by the enthusiasm of its developers, and needed a weapon to maintain German morale. The V-2s were constructed at the Mittelwerk site by prisoners from Mittelbau-Dora, the A-4 used a 74% ethanol/water mixture for fuel and liquid oxygen for oxidizer. The rocket reached a height of 80 km after shutting off the engine, the fuel and oxidizer pumps were driven by a steam turbine, and the steam was produced by concentrated hydrogen peroxide with sodium permanganate catalyst. Both the alcohol and oxygen tanks were an aluminium-magnesium alloy, the combustion burner reached a temperature of 2,500 to 2,700 °C
6.
Hermann Oberth
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Hermann Julius Oberth was an Austro-Hungarian-born German physicist and engineer. He is considered one of the fathers of rocketry and astronautics. Oberth was born to a Transylvanian Saxon family in Hermannstadt, Austria-Hungary, influenced by Vernes books and ideas, Oberth constructed his first model rocket as a school student at the age of 14. In his youthful experiments, he arrived independently at the concept of the multistage rocket, in 1915, Oberth was moved into a medical unit at a hospital in Sighișoara, Transylvania, in Austria-Hungary. There he found the time to conduct a series of experiments concerning weightlessness. By 1917, he showed designs of a missile using liquid propellant with a range of 180 miles to Hermann von Stein, on 6 July 1918, Oberth married Mathilde Hummel, with whom he had four children. Among these were a son who died as a soldier in World War II, in 1919, Oberth once again moved to Germany, this time to study physics, initially in Munich and later in Göttingen. In 1922, Oberths proposed doctoral dissertation on rocket science was rejected as utopian and he next had his 92-page work published privately in June 1923 as the somewhat controversial book, Die Rakete zu den Planetenräumen. By 1929, Oberth had expanded this work to a 429-page book titled Wege zur Raumschiffahrt, Oberth commented later that he made the deliberate choice not to write another doctoral dissertation. He wrote, I refrained from writing one, thinking to myself, Never mind, I will prove that I am able to become a greater scientist than some of you. Oberth criticized the German system of education, saying Our educational system is like an automobile which has strong rear lights, but looking forward, things are barely discernible. Hermann Oberth was finally awarded his licence in physics with the same paper that he had written before, by the University of Cluj, Romania, under professor Augustin Maior. Therefore, from 1924 through 1938, Oberth supported himself and his family by teaching physics and mathematics at the Stephan Ludwig Roth High School in Mediaş and this film was of enormous value in popularizing the ideas of rocketry and space exploration. One of Oberths main assignments was to build and launch a rocket as a publicity event just before the films premiere and he also designed the model of the Friede, the main rocket portrayed in the film. In the autumn of 1929, Oberth conducted a firing of his first liquid-fueled rocket motor. The engine was built by Klaus Riedel in a space provided by the Reich Institution of Chemical Technology. Indeed, Von Braun said of him, Hermann Oberth was the first, I, myself, owe to him not only the guiding-star of my life, but also my first contact with the theoretical and practical aspects of rocketry and space travel. A place of honor should be reserved in the history of science, in 1938, the Oberth family left Sibiu, Romania, for good, to first settle in Austria, then in Nazi Germany, then in the United States, and finally back to a free Germany
7.
Wernher von Braun
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He was one of the leading figures in the development of rocket technology in Nazi Germany, where he was a member of the Nazi Party and the SS. In his twenties and early thirties, von Braun worked in Germanys rocket development program, following the war, von Braun worked for the United States Army on an intermediate-range ballistic missile program before his group was assimilated into NASA. In 1975, he received the National Medal of Science and he continued insisting on the human mission to Mars throughout his life. Wernher von Braun was born on 23 March 1912 in the town of Wirsitz, in the Posen Province. He was the second of three sons and he belonged to a noble family, inheriting the German title of Freiherr. His father, conservative civil servant Magnus Freiherr von Braun, served as a Minister of Agriculture in the Reich Cabinet during the Weimar Republic, Von Braun had an older brother, Sigismund, and a younger brother, also named Magnus. After Wernher von Brauns Lutheran confirmation, his mother gave him a telescope, the family moved to Berlin in 1915 where his father worked at the Ministry of the Interior. He was taken into custody by the police until his father came to collect him. Wernher von Braun was an amateur pianist who could play Beethoven. He learned to both the cello and the piano at an early age and at one time wanted to become a composer. He took lessons from the composer Paul Hindemith, the few pieces of von Braun’s youthful compositions that exist are reminiscent of Hindemith’s style. Beginning in 1925, von Braun attended a school at Ettersburg Castle near Weimar. There he acquired a copy of By Rocket into Planetary Space by rocket pioneer Hermann Oberth, in 1928, his parents moved him to the Hermann-Lietz-Internat on the East Frisian North Sea island of Spiekeroog. Space travel had always fascinated von Braun, and from then on he applied himself to physics and mathematics to pursue his interest in rocket engineering. In 1930, he attended the Technische Hochschule Berlin, where he joined the Spaceflight Society, in spring 1932, he graduated from the Technische Hochschule Berlin, with a diploma in mechanical engineering. His early exposure to rocketry convinced him that the exploration of space would require far more applications of the current engineering technology. He also studied at ETH Zürich, although he worked mainly on military rockets in his later years there, space travel remained his primary interest. In 1930, von Braun attended a presentation given by Auguste Piccard, after the talk the young student approached the famous pioneer of high-altitude balloon flight, and stated to him, You know, I plan on traveling to the Moon at some time
8.
Ohio State University
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The Ohio State University, commonly referred to as Ohio State or OSU, is a large, primarily residential, public university in Columbus, Ohio. Founded in 1870 as a land-grant university and ninth university in Ohio with the Morrill Act of 1862, Hayes, and in 1878 the Ohio General Assembly passed a law changing the name to The Ohio State University. It has since grown into the third-largest university campus in the United States, along with its main campus in Columbus, Ohio State also operates a regional campus system with regional campuses in Lima, Mansfield, Marion, Newark, and Wooster. Ohio State athletic teams compete in Division I of the NCAA and are known as the Ohio State Buckeyes, athletes from Ohio State have won 100 Olympic medals. The university is a member of the Big Ten Conference for the majority of sports, the Ohio State mens ice hockey program competes in the Big Ten Conference, while its womens hockey program competes in the Western Collegiate Hockey Association. In addition, the OSU mens volleyball team is a member of the Midwestern Intercollegiate Volleyball Association, OSU is one of only 14 universities that plays Division I FBS football and Division I ice hockey. As of August 2015, the university had awarded a total of 714,512 degrees, alumni and former students have gone on to prominent careers in government, business, science, medicine, education, sports, and entertainment. Championed by the Republican stalwart Governor Rutherford B, Hayes, the Ohio State University was founded in 1870 as a land-grant university under the Morrill Act of 1862 as the Ohio Agricultural and Mechanical College. The school was originally within a community on the northern edge of Columbus. The university opened its doors to 24 students on September 17,1873, in 1878, the first class of six men graduated. The first woman graduated the following year, also in 1878, in light of its expanded focus, the Ohio legislature changed the name to the now-familiar The Ohio State University, with The as part of its official name. Ohio State began accepting students in the 1880s, and in 1891. It would later acquire colleges of medicine, dentistry, optometry, veterinary medicine, commerce, in 1916, Ohio State was elected into membership in the Association of American Universities. Michael V. Drake, former chancellor of the University of California, Irvine, in an attack against the campus on November 28,2016, an unrelated fluorine leak was called in for Watts Hall, resulting in the evacuation of the building to an outside courtyard. As firetrucks began to depart, Abdul Razak Ali Artan drove into the crowd, then emerged, the attack was stopped in under two minutes by OSU Police Officer Alan Horujko, who witnessed the attack after responding to the reported gas leak, and who shot and killed Artan. The universitys Buckeye Alert system was triggered and the campus was placed on lockdown, Ten were transported to local hospitals and one suspect was killed according to multiple sources. Local law enforcement and the FBI launched an investigation, according to authorities, Artan was inspired by terrorist propaganda from the Islamic State and radical Muslim cleric Anwar al-Awlaki. Ohio States 1, 764-acre main campus is about 2.5 miles north of the citys downtown, the historical center of campus is the Oval, quad of about 11 acres
9.
Impeller
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An impeller is a rotor used to increase the pressure and flow of a fluid. The velocity achieved by the impeller transfers into pressure when the movement of the fluid is confined by the pump casing. Impellers are usually short cylinders with an inlet to accept incoming fluid, vanes to push the fluid radially. The impeller made out of cast material in many cases may be called rotor, also. It is cheaper to cast the radial impeller right in the support it is fitted on, the rotor usually names both the spindle and the impeller when they are mounted by bolts. In a failing heart, mechanical circulatory devices often utilize a continuous axial-flow impeller pump design, open impeller Semi-open impeller Closed or shrouded impeller The main part of a centrifugal compressor is the impeller. An open impeller has no cover, therefore it can work at higher speeds, a compressor with a covered impeller can have more stages than one that has an open impeller. Some impellers are similar to small propellers but without the large blades, among other uses, they are used in water jets to power high speed boats. Since impellers have no large blades to turn, they can spin at much higher speeds than propellers, the water forced through the impeller is channelled by the housing, creating a water jet that propels the vessel forward. To work efficiently, there must be a fit between the impeller and the housing. The housing is fitted with a replaceable wear ring which tends to wear as sand or other particles are thrown against the housing side by the impeller. Vessels using impellers are normally steered by changing the direction of the water jet, compare to propeller and jet aircraft engines. Impellers in agitated tanks are used to mix fluids or slurry in the tank and this can be used to combine materials in the form of solids, liquids and gas. Mixing the fluids in a tank is important if there are gradients in conditions such as temperature or concentration. Another application of radial flow impellers are the mixing of very viscous fluids, axial flow impellers impose essentially bulk motion, and are used on homogenization processes, in which increased fluid volumetric flow rate is important. Impellers can be further classified principally into three sub-types Propellers Paddles Turbines All these can be discussed immediately after example, if one heats a pot of soup on the stove the pot will develop a temperature gradient. Mild agitation will increase the rate of heating by dissipating the heat through the entire pot, even more significant, agitation disturbs the soup directly in contact with the hotter pot surface. Highly turbulent flow at the surface is important to good heat transfer
10.
Aluminium
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Aluminium or aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal, Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is combined in over 270 different minerals. The chief ore of aluminium is bauxite, Aluminium is remarkable for the metals low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the industry and important in transportation and structures, such as building facades. The oxides and sulfates are the most useful compounds of aluminium, despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of these salts abundance, the potential for a role for them is of continuing interest. Aluminium is a soft, durable, lightweight, ductile. It is nonmagnetic and does not easily ignite, a fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation. The yield strength of aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel and it is easily machined, cast, drawn and extruded. Aluminium atoms are arranged in a cubic structure. Aluminium has an energy of approximately 200 mJ/m2. Aluminium is a thermal and electrical conductor, having 59% the conductivity of copper. Aluminium is capable of superconductivity, with a critical temperature of 1.2 kelvin. Aluminium is the most common material for the fabrication of superconducting qubits, the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts, particularly in the presence of dissimilar metals. In highly acidic solutions, aluminium reacts with water to form hydrogen, primarily because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium
11.
Space Shuttle
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The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U. S. National Aeronautics and Space Administration, as part of the Space Shuttle program. Its official program name was Space Transportation System, taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development, the first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. Five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, the Shuttle fleets total mission time was 1322 days,19 hours,21 minutes and 23 seconds. Shuttle components included the Orbiter Vehicle, a pair of solid rocket boosters. The Shuttle was launched vertically, like a rocket, with the two SRBs operating in parallel with the OVs three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, at the conclusion of the mission, the orbiter fired its OMS to de-orbit and re-enter the atmosphere. The orbiter then glided as a spaceplane to a landing, usually at the Shuttle Landing Facility of KSC or Rogers Dry Lake in Edwards Air Force Base. After landing at Edwards, the orbiter was back to the KSC on the Shuttle Carrier Aircraft. The first orbiter, Enterprise, was built in 1976 for use in Approach, four fully operational orbiters were initially built, Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in accidents, Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger, the Space Shuttle was retired from service upon the conclusion of Atlantiss final flight on July 21,2011. Nixons post-Apollo NASA budgeting withdrew support of all components except the Shuttle. The vehicle consisted of a spaceplane for orbit and re-entry, fueled by liquid hydrogen and liquid oxygen tanks. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service in 2011 after 135 missions, the program ended after Atlantis landed at the Kennedy Space Center on July 21,2011. Major missions included launching numerous satellites and interplanetary probes, conducting space science experiments, the first orbiter vehicle, named Enterprise, was built for the initial Approach and Landing Tests phase and lacked engines, heat shielding, and other equipment necessary for orbital flight. A total of five operational orbiters were built, and of these and it was used for orbital space missions by NASA, the US Department of Defense, the European Space Agency, Japan, and Germany. The United States funded Shuttle development and operations except for the Spacelab modules used on D1, sL-J was partially funded by Japan
12.
Space Shuttle main engine
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Built in the United States by Rocketdyne, the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,859 kN of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, concerted development of the began in the 1970s, with the first flight, STS-1. The RS-25 has undergone several upgrades over its history to improve the engines reliability, safety. The RS-25 operates at temperatures ranging from −253 °C to 3300 °C, the Space Shuttle used a cluster of three RS-25 engines mounted in the aft structure of the orbiter, with fuel being drawn from the external tank. Following each flight, the engines were removed from the orbiter, the RS-25 engine consists of various pumps, valves and other components which work in concert to produce thrust. Once in the MPS lines, the fuel and oxidizer each branch out into separate paths to each engine, in each branch, prevalves then allow the propellants to enter the engine. Once in the engine, the flow through low-pressure fuel and oxidizer turbopumps. From these HPTPs the propellants take different routes through the engine, meanwhile, fuel flows through the main fuel valve into regenerative cooling systems for the nozzle and MCC, or through the chamber coolant valve. Fuel passing through the MCC cooling system then passes back through the LPFTP turbine before being routed either to the tank pressurization system or to the hot gas manifold cooling system. Once in the injectors, the propellants are mixed and injected into the combustion chamber where they are ignited. The burning propellant mixture is ejected through the throat and bell of the engines nozzle. It boosts the liquid oxygens pressure from 0.7 to 2.9 MPa, during engine operation, the pressure boost permits the high-pressure oxidizer turbine to operate at high speeds without cavitating. The LPOTP, which measures approximately 450 by 450 mm, is connected to the vehicle propellant ducting, the HPOTP consists of two single-stage centrifugal pumps mounted on a common shaft and driven by a two-stage, hot-gas turbine. The main pump boosts the liquid oxygens pressure from 2.9 to 30 MPa while operating at approximately 28,120 rpm, the HPOTP discharge flow splits into several paths, one of which drives the LPOTP turbine. Another path is to, and through, the oxidizer valve. Another small flow path is tapped off and sent to the heat exchanger. The gas is sent to a manifold and then routed to pressurize the liquid oxygen tank, another path enters the HPOTP second-stage preburner pump to boost the liquid oxygens pressure from 30 to 51 MPa. It passes through the oxidizer preburner oxidizer valve into the oxidizer preburner, the HPOTP measures approximately 600 by 900 mm
