Electric-pump-fed engine

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Electric-feed rocket cycle. The oxidizer and fuel are fed to the pump which increases the pressure before injecting it into the combustion chamber. The pumps are actuated by an electric motor powered by batteries. An inverter converts the batteries' DC electricity to the AC needed by the motor. The fuel is also circulated around the outside of the combustion chamber and nozzle to prevent it from overheating. Electric feed rocket cycle.svg
Electric-feed rocket cycle. The oxidizer and fuel are fed to the pump which increases the pressure before injecting it into the combustion chamber. The pumps are actuated by an electric motor powered by batteries. An inverter converts the batteries' DC electricity to the AC needed by the motor. The fuel is also circulated around the outside of the combustion chamber and nozzle to prevent it from overheating.

The electric-pump-fed engine is a bipropellant rocket engine in which the fuel pumps are electrically powered, and so all of the input propellant is directly burned in the main combustion chamber, and none is diverted to drive the pumps. This differs from traditional rocket engine designs, in which the pumps are driven by a portion of the input propellants.

An electric cycle engine uses electric pumps to pressurize the propellants from a low-pressure fuel tank to high-pressure combustion chamber levels, generally from 0.2 to 0.3 MPa (29 to 44 psi) to 10 to 20 MPa (1,500 to 2,900 psi). The pumps are powered by an electric motor, with electricity from a battery bank.

Electrical pumps had been used in the secondary propulsion system of the Agena upper stage vehicle. [1]

As of December 2020, the only rocket engines to use electric propellant pump systems are the Rutherford engine, [2] ten of which power the Electron rocket, [2] and the Delphin engine, five of which power the first stage of Astra Space's Rocket 3. [3] On 21 January 2018, Electron was the first electric pump-fed rocket to reach orbit. [4]

In comparison to turbo-pumped rocket cycles such as staged combustion and gas generator, an electric cycle engine has potentially worse performance due to the added mass of batteries, but may have lower development and manufacturing costs due its mechanical simplicity, its lack of high temperature turbomachinery, and its easier controllability. [5]

See also

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RS-25 Space Shuttle and SLS main engine

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Rocketdyne J-2 Rocket engine

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Staged combustion cycle Rocket engine operation method

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Gas-generator cycle Rocket engine operation method

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RD-0124

The RD-0124 is a rocket engine burning liquid oxygen and kerosene in a staged combustion cycle. RD-0124 engines are used on the Soyuz-2.1b and Soyuz-2-1v. A slight variation of the engine, the RD-0124A, is used on the Angara rocket family URM-2 upper stage. RD-0124 is developed by Chemical Automatics Design Bureau in Voronezh.

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A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel and oxidizer; that is, both its fuel and oxidizer are gases which have been liquefied and are stored at very low temperatures. These highly efficient engines were first flown on the US Atlas-Centaur and were one of the main factors of NASA's success in reaching the Moon by the Saturn V rocket.

Fastrac was a turbo pump-fed, liquid rocket engine. The engine was designed by NASA as part of the low cost X-34 Reusable Launch Vehicle (RLV) and as part of the Low Cost Booster Technology project. This engine was later known as the MC-1 engine when it was merged into the X-34 project.

Rocket propellant Chemical or mixture used as fuel for a rocket engine

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XLR81

The Bell Aerosystems Company XLR81 was an American liquid-propellant rocket engine, which was used on the Agena upper stage. It burned UDMH and RFNA fed by a turbopump in a fuel rich gas generator cycle. The turbopump had a single turbine with a gearbox to transmit power to the oxidizer and fuel pumps. The thrust chamber was all-aluminum, and regeneratively cooled by oxidizer flowing through gun-drilled passages in the combustion chamber and throat walls. The nozzle was a titanium radiatively cooled extension. The engine was mounted on an hydraulic actuated gimbal which enabled thrust vectoring to control pitch and yaw. Engine thrust and mixture ratio were controlled by cavitating flow venturis on the gas generator flow circuit. Engine start was achieved by solid propellant start cartridge.

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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. 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.

Rutherford (rocket engine)

Rutherford is a liquid-propellant rocket engine designed by aerospace company Rocket Lab and manufactured in Long Beach, California. The engine is used on the company's own rocket, Electron. It uses LOX and RP-1 as its propellants and is the first flight-ready engine to use the electric-pump feed cycle. The rocket uses a similar engine arrangement to the Falcon 9; a two-stage rocket using a cluster of nine identical engines on the first stage, and one vacuum-optimized version with a longer nozzle on the second stage. This arrangement is also known as an octaweb. The sea-level version produces 24.9 kN (5,600 lbf) of thrust and has a specific impulse of 311 s (3.05 km/s), while the vacuum optimized-version produces 25.8 kN (5,800 lbf) of thrust and has a specific impulse of 343 s (3.36 km/s).

References

  1. George Paul Sutton (2006). History of Liquid Propellant Rocket Engines. AIAA. p. 126. ISBN   9781563476495.
  2. 1 2 "Propulsion". Rocket Lab. Archived from the original on 19 September 2016. Retrieved 19 September 2016.
  3. "Astra scrubs DARPA launch challenge attempt". 2 March 2020. Retrieved 17 December 2020.
  4. Ryan, Holly (21 January 2018). "Blast off! Rocket Lab successfully reaches orbit". The New Zealand Herald . Retrieved 21 January 2018.
  5. Rachov, Pablo (2010). "Electric feed systems for liquid propellant rocket engines" (PDF). Archived from the original (PDF) on 21 January 2018. Retrieved 3 February 2018.