Experimental Study of the Plume Characteristics of an Aged Monopropellant Hydrazine Thruster.

摘要

An experimental study of the exhaust plume of an aged (200,000 pulses), 0.44 N (0.1 lbf), hydrazine monopropellants thruster was performed with the goal of characterizing both the gas dynamic and contamination properties of the vacuum plume expansion. The thruster was operated in a high vacuum chamber over a thrust range from 0.44 to 1.10 N (0.1 to .25 lbf) with a nominal 0.14-sec-on/9.86-sec-off duty cycle using initial catalyst bed (Shell 405) temperatures of 367 K (200F), 478 K (400F), and 589 K (699F). Exhaust plume diagnostic systems employed included a mass spectrometer probe, a quartz crystal microbalance (QCM), a laser-Raman/Rayleigh scattering system, an electron beam fluorescence system, and a particle collection network. These systems determined plume species number densities and temperature, mass deposition rates, and the level of particulates in the plume; they also permitted visualization of the plume. Traditional engine performance parameters were also determined in order to relate performance and exhaust plume properties. (Author)