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Ramjet
A ramjet, or athodyd (aero thermodynamic duct), is a form of airbreathing jet engine that uses the forward motion of the engine to produce thrust. Since it produces no thrust when stationary (no ram air) ramjet-powered vehicles require an assisted take-off like a JATO, rocket assist to accelerate it to a speed where it begins to produce thrust. Ramjets work most efficiently at supersonic speeds around and can operate up to speeds of . Ramjets can be particularly useful in applications requiring a small and simple mechanism for high-speed use, such as missiles. The US, Canada, and UK had widespread ramjet powered missile defenses during the 1960s onward, such as the CIM-10 Bomarc and Bloodhound (missile), Bloodhound. Weapon designers are looking to use ramjet technology in artillery shells to give added range; a 120 mm mortar shell, if assisted by a ramjet, is thought to be able to attain a range of . They have also been used successfully, though not efficiently, as tip j ...
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Scramjet
A scramjet (supersonic combustion ramjet) is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully before combustion (hence ''ram''jet), but whereas a ramjet decelerates the air to subsonic velocities before combustion using shock cones, a scramjet has no shock cone and slows the airflow using shockwaves produced by its ignition source in place of a shock cone. This allows the scramjet to operate efficiently at extremely high speeds. History Before 2000 The Bell X-1 attained supersonic flight in 1947 and, by the early 1960s, rapid progress toward faster aircraft suggested that operational aircraft would be flying at "hypersonic" speeds within a few years. Except for specialized rocket research vehicles like the North American X-15 and other rocket-powered spacecraft, aircraft top speeds have remained level, generally in the range of M ...
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Airbreathing Jet Engine
An airbreathing jet engine (or ''ducted jet engine'') is a jet engine that ejects a propelling (reaction) jet of hot exhaust gases after first taking in atmospheric air, followed by compression, heating and expansion back to atmospheric pressure through a nozzle. Alternatively the reaction jet may include a cold jet of ducted bypass air which has been compressed by a fan before returning to atmospheric pressure through an additional nozzle. These engines are gas turbine engines. Engines using only ram for the compression process, and no turbomachinery, are the ramjet and pulsejet. All practical airbreathing jet engines heat the air by burning fuel. Alternatively a heat exchanger may be used ( nuclear-powered jet engine). Most modern jet engines are turbofans. They replaced turbojets as they use less fuel. Background The original air-breathing gas turbine jet engine was the turbojet. It was a concept brought to life by two engineers, Frank Whittle in England UK and Hans von Oha ...
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Bloodhound (missile)
The Bristol Bloodhound is a British ramjet powered surface-to-air missile developed during the 1950s. It served as the UK's main air defence weapon into the 1990s and was in large-scale service with the Royal Air Force (RAF) and the forces of four other countries. Part of sweeping changes to the UK's defence posture, the Bloodhound was intended to protect the RAF's V bomber bases to preserve the deterrent force, attacking bombers that made it past the Lightning interceptor force. Bloodhound Mk. I entered service in December 1958, the first British guided weapon to enter full operational service. This was part of Stage 1 upgrades to the defensive systems, in the later Stage 2, both Bloodhound and the fighters would be replaced by a longer-range missile code named Blue Envoy. When this was ultimately cancelled in 1957, parts of its design were worked into Bloodhound Mk. II, roughly doubling the range of the missile. The Mk. I began to be replaced by the Mk. II starting in 1964. ...
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CIM-10 Bomarc
The Boeing CIM-10 BOMARC (Boeing Michigan Aeronautical Research Center) (IM-99 Weapon System prior to September 1962) was a supersonic ramjet powered long-range surface-to-air missile (SAM) used during the Cold War for the air defense of North America. In addition to being the first operational long-range SAM and the first operational pulse doppler aviation radar,Tactical missile aerodynamics, Volume 141. P17. Michael J. Hemsch, American Institute of Aeronautics and Astronautics. American Institute of Aeronautics and Astronautics, 1992 it was the only SAM deployed by the United States Air Force. Stored horizontally in a launcher shelter with a movable roof, the missile was erected, fired vertically using rocket boosters to high altitude, and then tipped over into a horizontal Mach 2.5 cruise powered by ramjet engines. This lofted trajectory allowed the missile to operate at a maximum range as great as 430 mi (700 km). Controlled from the ground for most of its flig ...
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René Lorin
René Lorin (24 March 1877 – 16 January 1933) was a French aerospace engineer and inventor of the ramjet. In 1908 Lorin patented the first subsonic ramjet design. He published the principles of a ramjet in articles in the journal ''L'Aérophile'' from 1908 to 1913, expressing the idea that the exhaust from internal combustion engines could be directed into nozzles to create jet propulsion. He could not test this invention since there was no way at the time for an aircraft to go fast enough for a ramjet to function properly. When René Leduc applied for a patent on a ramjet design in 1933, he discovered Lorin's publications and tried to contact him, only to learn that he had recently died. Leduc thereafter paid homage to Lorin's work. René Lorin is a graduate of the École Centrale Paris École Centrale Paris (ECP; also known as École Centrale or Centrale) was a French grande école in engineering and science. It was also known by its official name ''École Centrale des A ...
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Tip Jet
A tip jet is a jet nozzle at the tip of some helicopter rotor blades, used to spin the rotor, much like a Catherine wheel firework. Tip jets replace the normal shaft drive and have the advantage of placing no torque on the airframe, thus not requiring the presence of a tail rotor. Some simple monocopters are composed of nothing but a single blade with a tip rocket. Tip jets can use compressed air, provided by a separate engine, to create jet thrust. Other types use a system that functions similarly to the afterburner (reheat) on a conventional jet engine, except that instead of reheating a gas jet, they serve as the primary heater, creating greater thrust than the flow of pre-compressed air alone; the best description of this is ''thrust augmentation''. Other designs includes ramjets or even a complete turbojet engine. Some, known as Rocket On Rotor systems, involve placing rockets on the tips of the rotor blades that are fueled from an onboard fuel tank. If the helicopter's ...
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Albert Fonó
Albert Fonó (born 2 July 1881 in Budapest, d. 21 November 1972 in Budapest), a successful Hungarian mechanical engineer who was one of the early pioneers of turbojet and ramjet propulsion and was first to patent a ramjet engine and a turbojet engine in 1928 (granted in 1932). Fonó graduated from the József Technical University in Budapest in 1903 and travelled widely, gaining experience working for German, Belgian, French and Swiss manufacturers, before attaining his Ph.D. His main specialty was energetics. He had 46 patents in 20 topics of research, including a steam boiler and an air compressor for mines. In 1915 he devised a solution for increasing the range of artillery, comprising a gun-launched projectile combined with a ramjet propulsion unit. This was to make it possible to obtain a long range with low initial muzzle velocities, allowing heavy shells to be fired from relatively lightweight guns. Fonó submitted his invention to the Austro-Hungarian Army but the prop ...
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Missile
In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocket is made guided). Missiles have five system components: targeting, guidance system, flight system, engine and warhead. Missiles come in types adapted for different purposes: surface-to-surface and air-to-surface missiles ( ballistic, cruise, anti-ship, anti-submarine, anti-tank, etc.), surface-to-air missiles (and anti-ballistic), air-to-air missiles, and anti-satellite weapons. Airborne explosive devices without propulsion are referred to as shells if fired by an artillery piece and bombs if dropped by an aircraft. Unguided jet- or rocket-propelled weapons are usually described as rocket artillery. Historically, the word ''missile'' referred to any projectile that is thrown, shot or propelled towards a target; this usag ...
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Artillery
Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower. Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armor. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannons, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called ''barrel artillery'', ''cannon artillery'', ''gun artillery'', or - a ...
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Comical History Of The States And Empires Of The Moon
''The Other World: Comical History of the States and Empires of the Moon'' (french: L’Autre monde ou les états et empires de la Lune) was the first of three satirical novels written by Cyrano de Bergerac. It was published posthumously in 1657 and, along with its companion work ''The States and Empires of the Sun'', is considered one of the earliest published science fiction stories. Arthur C. Clarke credited the book with the first description of rocket-powered spaceflight, and with the invention of the ramjet. Plot summary The book is narrated in the first person by a character also named Cyrano. Cyrano attempts to reach the Moon to prove there is a civilization that sees the Earth as its own moon. He launches himself into the sky from Paris by strapping bottles of dew to his body, but lands back on Earth. Believing he had traveled straight up and down, he is confused by local soldiers who tell him he is not in France; they escort him to the provincial governor who informs hi ...
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Pulsejet
300px, Diagram of a pulsejet A pulsejet engine (or pulse jet) is a type of jet engine in which combustion occurs in pulses. A pulsejet engine can be made with few or no moving parts, and is capable of running statically (i.e. it does not need to have air forced into its inlet, typically by forward motion). The best known example may be the Argus As 109-014 used to propel Nazi Germany's V-1 flying bomb. Pulsejet engines are a lightweight form of jet propulsion, but usually have a poor compression ratio, and hence give a low specific impulse. There are two main types of pulsejet engines, both of which use resonant combustion and harness the expanding combustion products to form a pulsating exhaust jet that produces thrust intermittently. The first is known as a valved or traditional pulsejet and it has a set of one-way valves through which the incoming air passes. When the air-fuel is ignited, these valves slam shut, which means that the hot gases can only leave through the engi ...
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Two-stage Rocket
A two-stage-to-orbit (TSTO) or two-stage rocket launch vehicle is a spacecraft in which two distinct stages provide propulsion consecutively in order to achieve orbital velocity. It is intermediate between a three-stage-to-orbit launcher and a hypothetical single-stage-to-orbit (SSTO) launcher. At liftoff the first stage is responsible for accelerating the vehicle. At some point the second stage detaches from the first stage and continues to orbit under its own power. An advantage of such a system over single-stage-to-orbit is that the most of the dry mass of the vehicle is not carried into orbit. This reduces the cost involved in reaching orbital velocity, as much of the structure and engine mass is ejected, and a larger percentage of the orbited mass is payload mass. An advantage over three or more stages is a reduction in complexity and fewer separation events, which reduces cost and risk of failure. Examples *Historical ** Cosmos-3M ** Delta IV (medium variant) ** Falco ...
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