Design and performance characterization of a sub-Newton N₂O monopropellant thruster

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• 作者：Guobiao Cai^a ; Wei Sun^a ; ^{buaasw@163.com} ; Jie Fang^a ; Mao Li^a ; Yu Cong^b ; Zhe Yang^c
• 关键词：Nitrous oxide ; Monopropellant ; Micro-propulsion ; Self-pressurization ; Preheating
• 刊名：Aerospace Science and Technology
• 出版年：2012
• 出版时间：December, 2012
• 年：2012
• 卷：23
• 期：1
• 页码：439-451
• 全文大小：3058 K

文摘

This paper describes the research at Beihang University for developing a sub-Newton thruster based on catalytic decomposition of nitrous oxide (N₂O) for fine attitude control of small spacecrafts. The characteristics of the N₂O self-pressurization feeding process as well as the preheating process of a sub-Newton N₂O thruster were studied. Experimental and simulated results indicated that the tank pressure decreases during the N₂O self-pressurization process. The influence on the preheating process of the surface emissivity, the preheating power, the thickness of combustor chamber and the insulation material, were compared. N₂O catalytic decomposition experiments were carried out to evaluate the reaction performance of Iridium impregnated modified alumina catalyst, such as activation temperature and reaction temperature. Successful activation and self-sustaining reaction were achieved at 523 K. It was found that the integral structure of the reactor and the loading factor of the catalyst-bed can influence the reaction effect. Based on further experiments looking for proper catalyst-bed, a thruster with a catalyst-bed was designed and fabricated. The vacuum performance of the thruster at different N₂O flow rates was evaluated using a vacuum experimental system, which consists of a vacuum chamber and a sub-Newton-thrust measuring stand. Static vacuum thrusts ranging from around 140 mN to 970 mN were achieved with the flow rates altering from around 0.1 g/s to 0.6 g/s. The highest specific impulse reached 1640 N?s/kg.