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Tap-off Cycle
The combustion tap-off cycle is a power cycle of a bipropellant rocket engine. The cycle takes a small portion of hot exhaust gas from the rocket engine's combustion chamber and routes it through turbopump turbines to pump fuel before being exhausted (similar to the gas-generator cycle). Since fuel is exhausted, the tap-off cycle is considered an open-cycle engine. The cycle is comparable to a gas-generator cycle engine with turbines driven by main combustion chamber exhaust rather than a separate gas generator or preburner. The J-2S rocket engine, a cancelled engine developed by NASA, used the combustion tap-off cycle and was first successfully tested in 1969. By 2013, Blue Origin, with their New Shepard launch vehicle, had successfully flight-tested the BE-3 engine using a tap-off cycle. According to Blue Origin, the cycle is particularly suited to human spaceflight due to its simplicity, with only one combustion chamber and a less stressful engine shutdown process. However, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combustion Tap-off Rocket Cycle
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion does not always result in fire, because a flame is only visible when substances undergoing combustion vaporize, but when it does, a flame is a characteristic indicator of the reaction. While the activation energy must be overcome to initiate combustion (e.g., using a lit match to light a fire), the heat from a flame may provide enough energy to make the reaction self-sustaining. Combustion is often a complicated sequence of elementary reaction, elementary Radical (chemistry), radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that incandescence, incandescent light in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaver 1
Reaver or Reavers may refer to: Fictional characters * Reavers (comics), cyborgs in Marvel Comics * Reaver (''Firefly''), in the 2002 TV series, and the related movie ''Serenity'' * villains in the 2017 film ''Logan'' * monster hunters in the 2019 TV series ''The Witcher'' * an enemy in The Runelords book series by David Farland * a pirate lord in the video games ''Fable II'' (2008) and ''Fable III'' (2010) * a class specialization in the video game ''Dark Age of Camelot'' * a class specialization in the video game '' Dragon Age: Inquisition'' * a unit in the video game ''StarCraft'' Other uses *''The Reavers'', a 2007 comic novel by George MacDonald Fraser *Reaver, a tool used to exploit a vulnerability in Wi-Fi Protected Setup Wi-Fi Protected Setup (WPS; originally, Wi-Fi Simple Config) is a network security standard to create a secure wireless home network. Created by Cisco and introduced in 2006, the point of the protocol is to allow home users who know little of w ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Engines By Cycle
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to Acceleration, accelerate without using the surrounding Atmosphere of Earth, air. A rocket engine produces thrust by Reaction (physics), reaction to exhaust expelled at high speed. Rocket engines work entirely from rocket propellant, propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with Airbreathing jet engine, airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, airfoils, Reaction control system, auxiliary reaction engines, gimballed thrust, Reaction wheel, momentum wheels, Thrust vectoring, deflection o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Engines
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 ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combustion
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion does not always result in fire, because a flame is only visible when substances undergoing combustion vaporize, but when it does, a flame is a characteristic indicator of the reaction. While the activation energy must be overcome to initiate combustion (e.g., using a lit match to light a fire), the heat from a flame may provide enough energy to make the reaction self-sustaining. Combustion is often a complicated sequence of elementary radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that incandescent light in the form of either glowing or a flame is produced. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas-generator Cycle
The gas-generator cycle is a power cycle of a pumped liquid bipropellant rocket engine. Part of the unburned propellant is burned in a gas generator (or preburner) and the resulting hot gas is used to power the propellant pumps before being exhausted overboard, and lost. Because of this loss, this type of engine is termed open cycle. Usage Gas-generator combustion engines include the following: * Vulcain, HM7B *Merlin *RS-68 *RS-27A *J-2X * F-1 *RD-107 * CE-20 * Rocket launch systems that use gas-generator combustion engines: *Ariane 5 *Falcon 9, Falcon Heavy *Delta IV *Saturn V *Soyuz * Geosynchronous Satellite Launch Vehicle III *Long March 3B, Long March 2F *Rocket Lab Neutron *Miura 5 See also * Combustion tap-off cycle * Expander cycle * Pressure-fed engine * 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, producin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staged Combustion Cycle (rocket)
The staged combustion cycle (sometimes known as topping cycle, preburner cycle, or closed cycle) is a Liquid-propellant rocket#Engine cycles, power cycle of a bipropellant rocket Rocket engine, engine. In the staged combustion cycle, propellant flows through multiple Rocket engine#Combustion chamber, combustion chambers, and is thus combustion, combusted in stages. The main advantage relative to other rocket engine power cycles is high fuel efficiency, measured through specific impulse, while its main disadvantage is reliability engineering, engineering complexity. Typically, propellant flows through two kinds of combustion chambers; the first called preburner and the second called main combustion chamber. In the preburner, a small portion of propellant, usually fuel-rich, is partly combusted, and the increasing volume flow is used to drive the turbopumps that feed the engine with propellant. The gas is then injected into the main combustion chamber and combusted completely with ... [...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] |
Pressure-fed Engine (rocket)
The pressure-fed engine is a class of rocket engine designs. A separate gas supply, usually helium, pressurizes the propellant tanks to force fuel and oxidizer to the combustion chamber. To maintain adequate flow, the tank pressures must exceed the combustion chamber pressure. Pressure fed engines have simple plumbing and have no need for complex and occasionally unreliable turbopumps. A typical startup procedure begins with opening a valve, often a one-shot pyrotechnic device, to allow the pressurizing gas to flow through check valves into the propellant tanks. Then the propellant valves in the engine itself are opened. If the fuel and oxidizer are hypergolic, they burn on contact; non-hypergolic fuels require an igniter. Multiple burns can be conducted by merely opening and closing the propellant valves as needed, if the pressurization system also has activating valves. They can be operated electrically, or by gas pressure controlled by smaller electrically operated valves. Care ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expander Cycle (rocket)
The expander cycle is a power cycle of a bipropellant rocket engine. In this cycle, the fuel is used to cool the engine's combustion chamber, picking up heat and changing phase. The now heated and gaseous fuel then powers the turbine that drives the engine's fuel and oxidizer pumps before being injected into the combustion chamber and burned. Because of the necessary phase change, the expander cycle is thrust limited by the square–cube law. When a bell-shaped nozzle is scaled, the nozzle surface area with which to heat the fuel increases as the square of the radius, but the volume of fuel to be heated increases as the cube of the radius. Thus beyond approximately 300 kN (70,000 lbf) of thrust, there is no longer enough nozzle area to heat enough fuel to drive the turbines and hence the fuel pumps. Higher thrust levels can be achieved using a bypass expander cycle where a portion of the fuel bypasses the turbine and or thrust chamber cooling passages and goes directly to the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASASpaceFlight
''NASASpaceflight.com'' is a private news website and forum which launched in 2005, covering crewed and uncrewed spaceflight and aerospace engineering news. Its original reporting has been referenced by various news outlets on spaceflight-specific news, such as MSNBC, USA Today and ''The New York Times'' among others. NASASpaceflight also produces videos and live streams of rocket launches online, with a special focus on developments at SpaceX's Starbase facility, for which they were recognized with an award by SpaceNews. NSF is owned and operated by managing editor Chris Bergin and content is produced by a team of spaceflight reporters, journalists, contributors, editors, photographers, and videographers across the United States and other countries. NASASpaceflight and NASASpaceflight.com are not affliated with NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefly Alpha
Firefly Alpha (Firefly α) is a two-stage orbital expendable launch vehicle developed by the American company Firefly Aerospace to compete in the commercial small satellite launch market. Alpha is intended to provide launch options for both full vehicle and rideshare customers. The first launch attempt was on 3 September 2021 but the vehicle did not reach orbit when one of the first stage engines failed during ascent. A second orbital test flight took place on 1 October 2022 and successfully reached orbit. Alpha deployed 7 satellites, however, due to the lower than intended deployment orbit, most of the satellites re-entered before reaching their intended design life a week after launch. History The initial 2014-vintage design of Alpha was two-stage-to-orbit vehicle with the first stage powered by an FRE-2 methalox engine, which consisted of twelve nozzles arranged in an aerospike configuration. The engine used methane and liquid oxygen as propellants, and completed a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
