A comparison of regenerative and conventional arcjet performance

Hoskins, W. Andrew; Butler, G. W.; Kull, A.E.

doi:10.2514/6.1994-3124

Cited by 4 publications

(2 citation statements)

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“…Based on such practical considerations, substantial work toward the development of high-power hydrogen arcjets has previously been undertaken with some ground based demonstrations extending above 100 kW. [8][9][10][11][12] It should be noted, however, that many space mission scenarios do not necessarily require the performance potential associated with hydrogen and could be entirely feasible with ammonia or hydrazine thereby avoiding highly demanding cryogenic fluid management challenges. The objective of this work was to empirically examine the performance of an innovative flex-propellant electrothermal arcjet using both hydrogen and simulated ammonia over a power range of 0.5-1 MW e with the deliberate aim of advancing the technology readiness level for potential space propulsion applications.…”

Section: Introductionmentioning

confidence: 99%

High Power Flex-Propellant Arcjet Performance

Litchford

2012

43rd AIAA Plasmadynamics and Lasers Conference

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A MW-class electrothermal arcjet based on a water-cooled, wall-stabilized, constricted arc discharge configuration was subjected to extensive performance testing using hydrogen and simulated ammonia propellants with the deliberate aim of advancing technology readiness level for potential space propulsion applications. The breadboard design incorporates alternating conductor/insulator wafers to form a discharge barrel enclosure with a 2.5-cm internal bore diameter and an overall length of approximately 1 meter. Swirling propellant flow is introduced into the barrel, and a DC arc discharge mode is established between a backplate tungsten cathode button and a downstream ringanode/spin-coil assembly. The arc-heated propellant then enters a short mixing plenum and is accelerated through a converging-diverging graphite nozzle. This innovative design configuration differs substantially from conventional arcjet thrusters, in which the throat functions as constrictor and the expansion nozzle serves as the anode, and permits the attainment of an equilibrium sonic throat (

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Section: Introductionmentioning

confidence: 99%

High Power Flex-Propellant Arcjet Performance

Litchford

2012

43rd AIAA Plasmadynamics and Lasers Conference

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“…Based on such practical considerations, substantial work toward the development of high-power hydrogen arcjets has previously been undertaken with some ground based demonstrations extending above 100 kW. [9][10][11][12][13] The objective of this work was to extend the empirical power range to the megawatt level with the deliberate aim of advancing the technology readiness level for potential space propulsion applications. This was made possible through the availability of a MW-class multi-gas arc-heater device recently commissioned at NASA-MSFC and by leveraging related research efforts directed at the establishment of a hyperthermal environments simulator for nuclear rocket engine development.…”

Section: Introductionmentioning

confidence: 99%

High Power Hydrogen Arcjet Performance Characterization

Litchford

2011

42nd AIAA Plasmadynamics and Lasers Conference

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A MW-class hydrogen arcjet based on a water-cooled, wall-stabilized, constricted arc discharge configuration was subjected to extensive performance testing with the deliberate aim of advancing technology readiness level for potential space propulsion applications. The breadboard design incorporates alternating conductor/insulator wafers to form a discharge barrel enclosure with a 2.5-cm internal bore diameter and an overall length of approximately 1 meter. Swirling hydrogen flow is introduced into the barrel, and a DC arc discharge mode is established between a tungsten cathode button at the back plate and a ring-anode/spin-coil assembly at the exit where the heated flow is choked and accelerated in a graphite nozzle having a nominal throat diameter of 7 mm. During the performance tests, hydrogen flow rates were varied between 7-11 g/s with applied electrical power ranging up to 1.05 MW and specific input power ranging up to 105 MJ/kg. The minimal run duration for each test was 60 sec, which was adequate for the establishment of steady state operating conditions. Observed electric-to-thermal conversion efficiencies were in the range of 50-60 percent as determined via a simple heat balance method based on electrical power input and coolant water calorimeter measurements. These results were also found to closely match predictions based on an equilibrium sonic throat method. Moreover, a simple bi-linear fit was constructed which accurately correlated arc efficiency over the full range of applied power and hydrogen flow rates. Inferred specific impulse performance accounting for hydrogen recombination kinetics during the expansion process implied nearly frozen flow in the nozzle with inferred thrust efficiencies in the range of 44-56 percent. Successful completion of this test series represents a fundamental milestone in the progression of high power arcjet technology, and it is hoped that the results may serve as a reliable touchstone for the future development of MW-class regeneratively-cooled plasma rockets. The limited range of investigated specific input power constrains achievable performance, however, and represents a notable experimental deficiency in need of redress.It is therefore recommended that a follow-on test program be commissioned to extend the operating range to 800-1000 MJ/kg at MW-scale power levels. Nomenclature€ g 0 = gravitational acceleration at sea level € I = current € Isp = specific impulse € ˙ m = mass flow rate € p = pressure € P = electrical or jet-kinetic power € Q = thermal power € T = temperature € V = voltage € η = efficiency € φ = specific power

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