复合推进剂压力耦合试验方法及燃烧响应机理研究

Low frequency acoustic pressure oscillation that occurs in composited solid propellant rocket motors is one of the major issues during the development of large aspect ratio tactical missiles. Based on this thorny problem，the mechanism of pressure coupled response for composite solid propellants will be investigated experimentally and numerically in this work，for the purpose of exploring the driving mechanism of combustion instability. Firstly, a rotary valve test will be improved so as to measure the pressure coupled response function under the conditions of high pressure and low frequency. Based on rotary valve test, the effects of propellant formulation and working condition on pressure coupled response function will be systematically analyzed. Secondly, based on the pulsed T-burner testing method, the effects of pulse intensity and rate on combustion instability will be studied to establish the stability margin of composite solid propellant. Finally, a numerical model of pressure coupled response for composite solid propellants will be established, and the coupling mechanism between acoustic, flow filed and combustion process will be revealed. Based on above research, the combined combustion effects of composite propellants on combustion instability will be summarized to provide theoretical guidance for the improvement of solid propellants and the evaluation of combustion instability in solid rocket motors.

采用复合固体推进剂的固体火箭发动机中出现低频压力振荡现象是大长径比战术武器研制过程中遇到的重大问题，本项目针对该难题拟开展复合推进剂压力耦合试验方法及燃烧响应试验研究，同时研究压力耦合响应数值计算方法，深入分析复合推进剂压力耦合响应诱发的不稳定燃烧机理。首先，设计一种旋转阀燃烧器，使其能在高压低频下测试复合推进剂压力耦合响应函数，在此基础上，对典型复合推进剂开展压力耦合响应特性研究，探索配方及工作条件对压力耦合响应函数的影响规律；其次，基于脉冲触发T型燃烧器，研究脉冲强度及脉冲增长率对复合推进剂不稳定燃烧的诱发机理，找到复合推进剂在脉冲触发条件下的稳定性裕度；最后，建立复合推进剂压力耦合响应数值计算模型，探索振荡条件下声场、流场与推进剂燃烧过程的耦合机理。通过以上研究，归纳复合推进剂对固体火箭发动机不稳定燃烧的综合作用，为推进剂装药配方研发及固体火箭发动机不稳定燃烧预示提供理论指导。

本项目针对该难题拟开展复合推进剂压力耦合试验方法及燃烧响应试验研究，同时研究压力耦合响应数值计算方法，深入分析复合推进剂压力耦合响应诱发的不稳定燃烧机理。首先，设计了一种旋转阀燃烧器，开展了冷流及热流试验，根据试验中获取的燃烧室压强数据及有效面积变化数据，计算获取了被测推进剂在不同转速（振荡频率）条件下的压强耦合响应函数。其次，基于脉冲触发T型燃烧器，开展了脉冲激励对复合推进剂燃烧不稳定的诱导机理研究，建立脉冲幅值的零维和一维理论模型以及平均压强上升量的零维理论模型，并利用T型燃烧器脉冲实验对理论模型进行验证。最后，基于复合推进剂的BDP微尺度燃烧模型，建立复合推进剂压力耦合响应数值计算模型，探索振荡条件下声场、流场与推进剂燃烧过程的耦合机理。