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Steam Rocket
A steam rocket (also known as a hot water rocket) is a thermal rocket that uses water held in a pressure vessel at a high temperature, such that its saturated vapor pressure is significantly greater than ambient pressure. The water is allowed to escape as steam through a rocket nozzle to produce thrust. Steam rockets are usually pressure fed, but more complex designs using solar energy or nuclear energy have been proposed. They are probably best known for their use in rocket-powered cars and motorcycles, and they are the type used in aeolipile. Principle of operation Water, while under pressure, is heated up to a high temperature (approx. 250–500 °C). As the hot water goes through the nozzle (usually a de Laval nozzle) and the pressure reduces, the water flashes to steam pressing on the nozzle, and leaving at high speed. By the recoil the rocket accelerates in the opposite direction to the steam. The nozzle of hot water rockets must be able to withstand high pressure, hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Rocket
A thermal rocket is a rocket engine that uses a propellant that is externally heated before being passed through a nozzle to produce thrust, as opposed to being internally heated by a redox (combustion) reaction as in a chemical rocket. Thermal rockets can theoretically give high performance, depending on the fuel used and design specifications, and a great deal of research has gone into a variety of types. However, aside from the simple cold gas thruster and steam rocket, none have proceeded past the testing stage. Theory For a rocket engine, the efficiency of propellant use (the amount of impulse produced per mass of propellant) is measured by the specific impulse (I_), which is proportional to the effective exhaust velocity. For thermal rocket systems, the specific impulse increases as the square root of the temperature, and inversely as the square root of the molecular mass of the exhaust. In the simple case where a thermal source heats an ideal Monatomic gas reaction mass, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skycycle X-2
The Skycycle X-2 was a steam-powered rocket owned by Evel Knievel and flown during his Snake River Canyon jump in Idaho in 1974. An earlier prototype was designed, named the Skycycle X-1, by Doug Malewicki and retired U.S. Navy engineer Robert Truax. It was tested in November 1973 and dove in the Snake River. The Skycycle X-2 was designed by Truax, and ridden by Knievel in his attempt to jump the Snake River approximately west of Shoshone Falls near the city of Twin Falls, Idaho, on September 8, 1974. The parachute deployed during the launch, causing the stunt to fail. A later analysis showed that a design flaw in a mechanical parachute retention cover, which did not properly take base drag into account, caused the premature parachute deployment. Following the failed jump, Truax blamed Knievel for the failure and vice versa. Later, Truax accepted full responsibility for the failure. The jump Although the parachute deployed early, the aerial photographs show the X-2 cleared t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steampunk
Steampunk is a subgenre of science fiction that incorporates retrofuturistic technology and aesthetics inspired by 19th-century industrial steam-powered machinery. Steampunk works are often set in an alternative history of the Victorian era or the American "Wild West", where steam power remains in mainstream use, or in a fantasy world that similarly employs steam power. Steampunk most recognizably features anachronistic technologies or retrofuturistic inventions as people in the 19th century might have envisioned them — distinguishing it from Neo-Victorianism — and is likewise rooted in the era's perspective on fashion, culture, architectural style, and art. Such technologies may include fictional machines like those found in the works of H. G. Wells and Jules Verne. Other examples of steampunk contain alternative-history-style presentations of such technology as steam cannons, lighter-than-air airships, analog computers, or such digital mechanical computers as Charles B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science Fiction
Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel universes, extraterrestrial life, sentient artificial intelligence, cybernetics, certain forms of immortality (like mind uploading), and the singularity. Science fiction predicted several existing inventions, such as the atomic bomb, robots, and borazon, whose names entirely match their fictional predecessors. In addition, science fiction might serve as an outlet to facilitate future scientific and technological innovations. Science fiction can trace its roots to ancient mythology. It is also related to fantasy, horror, and superhero fiction and contains many subgenres. Its exact definition has long been disputed among authors, critics, scholars, and readers. Science fiction, in literature, film, television, and other media, has beco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Engine
A jet engine is a type of reaction engine discharging a fast-moving jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include rocket, Pump-jet, water jet, and hybrid propulsion, the term typically refers to an internal combustion airbreathing jet engine such as a turbojet, turbofan, ramjet, or pulse jet engine, pulse jet. In general, jet engines are internal combustion engines. Airbreathing jet engines typically feature a Axial compressor, rotating air compressor powered by a turbine, with the leftover power providing thrust through the propelling nozzle—this process is known as the Brayton cycle, Brayton thermodynamic cycle. Jet aircraft use such engines for long-distance travel. Early jet aircraft used turbojet engines that were relatively inefficient for subsonic flight. Most modern subsonic jet aircraft use more complex High-bypass turbofan, high-bypass turbofan engines. They give higher speed and greater fuel eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Engine
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordance with Newton's third law. Most rocket engines use the combustion of reactive chemicals to supply the necessary energy, but non-combusting forms such as cold gas thrusters and nuclear thermal rockets also exist. Vehicles propelled by rocket engines are commonly called rockets. Rocket vehicles carry their own oxidiser, unlike most combustion engines, so rocket engines can be used in a vacuum to propel spacecraft and ballistic missiles. Compared to other types of jet engine, rocket engines are the lightest and have the highest thrust, but are the least propellant-efficient (they have the lowest specific impulse). The ideal exhaust is hydrogen, the lightest of all elements, but chemical rockets produce a mix of heavier species, reducing the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Rocket
A water rocket is a type of model rocket using water as its reaction mass. The water is forced out by a pressurized gas, typically compressed air. Like all rocket engines, it operates on the principle of Newton's third law of motion. Water rocket hobbyists typically use one or more plastic soft drink bottle as the rocket's pressure vessel. A variety of designs are possible including multi-stage rockets. Water rockets are also custom-built from composite materials to achieve world record altitudes. Operation The bottle is partly filled with water and sealed. The bottle is then pressurized with a gas, usually air compressed from a bicycle pump, air compressor, or cylinder up to 125 psi, but sometimes CO2 or nitrogen from a cylinder are used. Water and gas are used in combination, with the gas providing a means to store energy, as it is compressible, and the water increasing the propellant mass fraction and providing greater force when ejected from the rocket's nozzle. Someti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Salt-water Rocket
A nuclear salt-water rocket (NSWR) is a theoretical type of nuclear thermal rocket which was designed by Robert Zubrin. In place of traditional chemical propellant, such as that in a chemical rocket, the rocket would be fueled by salts of plutonium or 20 percent enriched uranium. The solution would be contained in a bundle of pipes coated in boron carbide (for its properties of neutron absorption). Through a combination of the coating and space between the pipes, the contents would not reach critical mass until the solution is pumped into a reaction chamber, thus reaching a critical mass, and being expelled through a nozzle to generate thrust. Proposed design Chemical rockets use heat energy produced by a chemical reaction to heat the gas products. The hot products exit through a propulsion nozzle at a very high speed, creating thrust. In a nuclear thermal rocket (NTR), thrust is created by heating a fluid by using a nuclear fission reactor. The lower the molecular weight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-Stoff
T-Stoff (; 'substance T') was a stabilised high test peroxide used in Germany during World War II. T-Stoff was specified to contain 80% (occasionally 85%) hydrogen peroxide (H2O2), remainder water, with traces (<0.1%) of stabilisers. Stabilisers used included 0.0025% , a mixture of phosphoric acid, and 8-oxyquinoline, and sodium stannate. Uses The decomposition of T-Stoff into hot steam and oxygen caused by the addition of the catalyst |
Walter HWK 109-507
The HWK 109-507 was a liquid-propellant rocket engine developed by Germany during World War II. It was used to propel the Hs 293 anti-ship guided missile. It was produced by Hellmuth Walter Kommanditgesellschaft (HWK). Like other Walter engines it used hydrogen peroxide as a propellant. Missile The Hs293 has been variously described as a missile or as a boosted glide bomb. It consisted of an SC500 bomb casing, fitted with wings, engine and radio control. Control equipment was housed in a rearward extension of the bomb casing but the motor was mounted in a separate housing beneath. It had originally been developed as an unpowered glide bomb, "Gustav Schwartz Propellerwerke", and the engine was added later. After flight tests, a visible tracking flare was also added, in a further rearward extension. As the engine was mounted below the missile fuselage, the exhaust nozzle pointed downwards at 30°, so as to align the line of thrust with the centre of gravity of the missile. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter HWK 109-500
The Walter HWK 109-500 was a liquid-fuelled rocket engine developed by Walter in Germany during the Second World War. Description The 109-500 is a self-contained, modular monopropellant ''Starthilfe'' (take-off assist) engine in a pod, able to produce 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. The T-Stoff monopropellant, stored in the large spherical tank within the ''Starthilfe'' module's forward end, needed to react with a catalyst to provide the boosting thrust for an aircraft on takeoff - this Z-Stoff sodium or calcium-based, alkaline permanganate-compound (in an aqueous solution) catalyst was provided in a small tank above the reaction chamber just forward of the exhaust nozzle, with compressed air from a network of five pressure tanks driving the monopropellant and catalyst together through the reaction chamber, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Payload Fraction
In aerospace engineering, payload fraction is a common term used to characterize the efficiency of a particular design. Payload fraction is calculated by dividing the weight of the payload by the takeoff weight of aircraft. Fuel represents a considerable amount of the overall takeoff weight, and for shorter trips it is quite common to load less fuel in order to carry a lighter load. For this reason the useful load fraction calculates a similar number, but based on the combined weight of the payload and fuel together. Propeller-driven airliners had useful load fractions on the order of 25–35%. Modern jet airliners have considerably higher useful load fractions, on the order of 45–55%. For spacecraft the payload fraction is often less than 1%, while the useful load fraction is perhaps 90%. In this case the useful load fraction is not a useful term, because spacecraft typically cannot reach orbit without a full fuel load. For this reason the related term propellant mass fractio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
