Arcjet rocket

About: Arcjet rocket is a research topic. Over the lifetime, 1121 publications have been published within this topic receiving 9687 citations. The topic is also known as: Arcjet.

Arcjet Nozzle Design Impacts

Abstract: The effect of nozzle configuration on the operating characteristics of a low power dc arcjet thruster was determined. A conical nozzle with a 30 deg converging angle, a 20 deg diverging angle, and an area ratio of 225 served as the baseline case. Variations on the geometry included bell-shaped contours both up and downstream, and a downstream trumpet-shaped contour. The nozzles were operated over a range of specific power near that anticipated for on-orbit operation. Mass flow rate, thrust, current, and voltage were monitored to provide accurate comparisons between nozzles. The upstream contour was found to have minimal effect on arcjet operation. It was determined that the contour of the divergent section of the nozzle, that serves as the anode, was very important in determining the location of arc attachment, and thus had a significant impact on arcjet performance. The conical nozzle was judged to have the optimal current/voltage characteristics and produced the best performance of the nozzles tested.

Discharge features in a steady-state nitrogen arcjet engine with an expansion nozzle

Abstract: Nitrogen discharges in a 10-kW-class water-cooled arcjet engine were studied by means of spectroscopic diagnostics. The atomic excitation temperature and electron density in the constrictor increased from 15,000 to 18,000 K and from 1/spl times/10/sup 15/ to 2/spl times/10/sup 16/ cm/sup /spl minus/3/, respectively, with input power levels of 7-11 kW. An increase in the mass flow rate raised the electron density because of enhanced thermal pinch effect of the arc column. In the expansion nozzle, the pressure and electron density decreased drastically downstream, and therefore the plasma was expected to be in high non-equilibrium. The N/sub 2//sup +/ vibrational temperature reached about 6,000 K at the nozzle exit, and the N/sub 2//sup +/ rotational temperature decreased gradually resulting in a range of 1,000-2,500 K. >

Performance testing of a solid propellant pulsed plasma microthruster.

Abstract: Extensive performance testing has been carried out on a solid propellant, pulsed plasma microthruster essentially identical to the four units aboard the DOD, Lincoln Experimental Satellite (LES)-6. Tests include measurements of thrust, specific impulse, thrust vector, impulse bit repeatability, intermittency and endurance. The results show good impulse bit repeatability and a well defined thrust vector. The impulse bit, with a 1.85-joule input, was found to be approximately 26 micronewton-seconds at 190 seconds specific impulse. Based upon the results of the intermittency tests, a better understanding of the intermittency mechanism has been achieved.

Electron densities and temperatures in a diamond-depositing direct-current arcjet plasma

Abstract: Langmuir probe measurements of electron density and temperature are made in the plume of a dc arcjet reactor. A dc arc is struck in an argon or argon/hydrogen mixture at 6 atm pressure and expands through a converging/diverging nozzle into the reactor with a pressure of 25 Torr. Methane and methane/nitric oxide are added in the diverging nozzle, and diamond film grows on a substrate in the gas plume. Electron temperatures of 1–2 eV are significantly hotter than the neutral gas temperature in the plume. Electron densities range from 1010 to 1013 cm−3, well above the Saha equilibrium for the gas temperature and pressure and well below the equilibrium for the electron temperature.