Performance Evaluation of a Hydroxylammonium-Nitrate-Based Monopropellant Thruster with Discharge Plasma System

摘要

Hydroxylammonium nitrate (HAN)-based monopropellant thrusters have been continuously researched and developed as a replacement for conventional hydrazine thrusters. An ignition system by utilizing discharge plasma of noble gas, called discharge plasma system, has been proposed in substitution for the conventional solid catalysts and evaluated the effects on ignition characteristics of swirl strength (geometric swirl number) and mass flow rate of argon gas. However, the performance characteristics of a laboratory model HAN-based monopropellant thruster with discharge plasma system under vacuum condition are not well understood. The objectives of the study are to experimentally evaluate the effects on performance characteristics of the monopropellant mass flow rate by the measurements of thrust, pressure, and emission spectra. The paper discusses the performance characteristics in terms of conditions that the characteristic exhaust velocity efficiency, thrust efficiency, specific impulse, and power consumption. At the feed pressure of 0.6 MPa, maximum thrust of 0.50 N was achieved with power consumption of 564 W and monopropellant mass flow rate of 0.31 g/s, in conjunction with specific impulse of 109 s, C-star efficiency with argon plasma of 41%, and thrust efficiency of 47%. Additionally, the spectra of reaction products were observed by spectrometer.