The gas-generator cycle is a power cycle of a pumped liquid
bipropellant rocket
A liquid-propellant rocket or liquid rocket utilizes a rocket engine that uses liquid propellants. Liquids are desirable because they have a reasonably high density and high specific impulse (''I''sp). This allows the volume of the propellant t ...
engine
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...
. Part of the unburned propellant is burned in a
gas generator
A gas generator is a device for generating gas. A gas generator may create gas by a chemical reaction or from a solid or liquid source, when storing a pressurized gas is undesirable or impractical.
The term often refers to a device that uses a ...
(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:
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Vulcain,
HM7B
The HM7B is a European cryogenic upper stage rocket engine used on the vehicles in the Ariane rocket family. It will be replaced by Vinci, which will act as the new upper stage engine on Ariane 6. Nearly 300 engines have been produced to date. ...
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Merlin
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RS-68
The Aerojet Rocketdyne RS-68 (Rocket System 68) is a liquid-fuel rocket engine that uses liquid hydrogen (LH2) and liquid oxygen (LOX) as propellants in a gas-generator power cycle. It is the largest hydrogen-fueled rocket engine ever flown.
I ...
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RS-27A
The RS-27A is a liquid-fuel rocket engine developed in 1980s by Rocketdyne for use on the first stage of the Delta II and Delta III launch vehicles. It provides of thrust burning RP-1 and LOX in a gas-generator cycle. The engine is a modified v ...
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J-2X
The J-2X is a liquid-fueled cryogenic rocket engine that was planned for use on the Ares rockets of NASA's Constellation program, and later the Space Launch System. Built in the United States by Aerojet Rocketdyne (formerly, Pratt & Whitney Rocke ...
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F-1
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RD-107
The RD-107 and its sibling, the RD-108, are a type of rocket engine initially used to launch R-7 Semyorka missiles. RD-107 engines were later used on space launch vehicles based on the R-7. , very similar RD-107A and RD-108A engines are used to la ...
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CE-20
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Rocket launch systems that use gas-generator combustion engines:
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Ariane 5
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Falcon 9
Falcon 9 is a partially reusable medium lift launch vehicle that can carry cargo and crew into Earth orbit, produced by American aerospace company SpaceX.
The rocket has two stages. The first (booster) stage carries the second stage and pay ...
,
Falcon Heavy
Falcon Heavy is a partially reusable heavy-lift launch vehicle that is produced by SpaceX, an American aerospace manufacturer. The rocket consists of two strap-on boosters made from Falcon 9 first stages, a center core also made from a Falc ...
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Delta IV
Delta IV is a group of five expendable launch systems in the Delta rocket family introduced in the early 2000s. Originally designed by Boeing's Defense, Space and Security division for the Evolved Expendable Launch Vehicle (EELV) program, t ...
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Saturn V
Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, with three stages, and powered with liquid fuel. It was flown from 196 ...
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Soyuz Soyuz is a transliteration of the Cyrillic text Союз ( Russian and Ukrainian, 'Union'). It can refer to any union, such as a trade union (''profsoyuz'') or the Union of Soviet Socialist Republics (Сою́з Сове́тских Социалис ...
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Geosynchronous Satellite Launch Vehicle III
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Long March 3B
The Long March 3B (, ''Chang Zheng 3B''), also known as the CZ-3B and LM-3B, is a Chinese orbital launch vehicle. Introduced in 1996, it is launched from Launch Area 2 and 3 at the Xichang Satellite Launch Center in Sichuan. A three-stage rock ...
,
Long March 2F
The Long March 2F ( ''Changzheng 2F''), also known as the CZ-2F, LM-2F and Shenjian (, "Divine Arrow"), is a Chinese orbital carrier rocket, part of the Long March 2 rocket family. Designed to launch crewed Shenzhou spacecraft, the Long Mar ...
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Rocket Lab Neutron
Neutron is a medium-lift two-stage launch vehicle under development by Rocket Lab. Announced on 1 March 2021, the vehicle is being designed to be capable of delivering a payload of to low Earth orbit in a partially reusable configuration, an ...
"Neutron, Rocket Lab"
/ref>
*Miura 5
Miura 5 is a two-stage European orbital recoverable launch vehicle of the Spanish company PLD Space currently under development. Miura 5 will be 24.9 m long, capable of inserting 900 kg of payload into a low Earth orbit (LEO), featuring an ...
See also
* Combustion 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 exhaus ...
* Expander cycle
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 ...
* Pressure-fed engine
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 th ...
* 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 accorda ...
* Staged combustion cycle
References
External links
Rocket power cycles
at NASA
{{Thermodynamic cycles
Combustion
Rocket engines
Spacecraft propulsion
Thermodynamic cycles