The aim of the present paper is the investigation of a monopropellant engine based on the exothermic decomposition of nitrous oxide, as a “green” substitute of the most common but highly toxic hydrazine-based systems. First, a general procedure for the design of such a system, in terms of sizing of the catalytic chamber and of the nozzle for prescribed mission requirements, is defined. This procedure is applied for the design of an 800-mN-class thruster prototype, with catalysts based on palladium as active phase on alumina pellets support. Such prototype is experimentally tested highlighting first the nitrous oxide decomposition behavior and issues related to an optimization of system thermal insulation for reducing energy losses. Finally, the measured engine performance are presented and discussed, including a comparison with the results obtained with the same system in a cold-flow operation mode, showing the gain in terms of increased specific impulse and reduced propellant consumption due to the exploitation of the thermal energy obtained from nitrous oxide decomposition.

本文的目的是研究基于一氧化二氮放热分解的单推进剂发动机，作为最常见但剧毒的肼基系统的“绿色”替代品。首先，根据用于规定任务要求的催化室和喷嘴的尺寸，定义了用于设计这种系统的一般程序。该程序适用于800 mN级推进器原型的设计，其中基于钯的催化剂作为氧化铝颗粒载体上的活性相。对这种原型进行了实验测试，突出显示了一氧化二氮的分解行为以及与优化系统隔热以减少能量损失有关的问题。最后，介绍并讨论了测得的发动机性能，