ADN基推力器中红外吸收光谱燃烧诊断

ADN（二硝酰胺铵盐）基单组元绿色推进技术是空间推进领域的国际研究热点，目前国内外对ADN基推进剂分解和燃烧过程缺乏统一、完善的燃烧动力学机理，尤其欠缺对推力器内部燃烧过程和关键中间产物定量信息的实验研究。本文通过发展先进中红外光谱诊断技术（QCLAS），实时诊断ADN基推进剂分解、燃烧反应中的CO，N₂O多种关键组分浓度、燃气温度等关键参数。推力器稳态点火测量结果验证了ADN推进剂催化分解和燃烧两步反应阶段理论研究，脉冲点火下组分浓度变化规律呈现与脉冲序列一致特性，验证了推力器正常工作的稳定性和可靠性。基于测量结果初步评估了ADN基推力器性能，特征速度达1130m/s，达到同类型肼推力器标准，验证了该绿色推力器良好的应用前景。

Mid-infrared absorption combustion diagnostics for an ADN based thruster

ADN monopropellant green space propulsion is perceived as a focus of the space propulsion research worldwide. Experimental study is in urgent requirement for understanding the combustion process in the ADN based thruster and for quantitative evaluation and optimization of the combustion stability and the thruster performance. In this paper, experiments were conducted to measure the concentration of the key intermediate products (CO, N₂O) and the temperature of the combustion gas flow based on the mid-infrared quantum cascade laser absorption spectroscopy (QCLAS). Two main ignition modes of the 1 N ADN based thruster are studied: the steady-state firing and the pulse-mode firing over the injection pressure of 0.5~1.2MPa bar with catalytic bed length of 19 mm, corresponding to a current thruster prototype. It is found in the steady-state firing experiments that the whole process can be divided into the catalytic decomposition stage and the combustion stage, and the combustion kinetics mechanism of the monopropellant is experimentally demonstrated. Experiments for the pulse-mode firing show the variance of the measured multispecies concentration and temperature in consistence with the pulse trains, verifying the good performance of the thruster pulse-mode firing operation.