基于高速摄像和激光吸收光谱的固体推进剂交变应变燃烧研究

Combustion Characteristics of AP-HTPB Propellant Under Oscillating Strains with High-Speed Imaging and Laser Absorption Spectroscopy

针对固体推进剂燃烧特性容易受到机械应变的作用,设计开发了一套附带光学视窗的固体推进剂燃烧测量系统,并基于高速摄像以及激光吸收光谱方法,研究了机械应变对AP-HTPB固体推进剂燃速、CO_(2)浓度以及燃烧温度的影响.结果表明:对于静态应变条件,在-10%~10%的机械应变范围内,推进剂燃速、温度和CO_(2)浓度随应变量的增加而增加.其中,燃速变化范围为1.72~2.1 mm/s,推进剂燃烧温度变化范围为1490~1680 K,CO_(2)空间积分浓度变化范围为0.138~0.165 cm.对于交变应变条件,推进剂燃速变化呈现分阶段特征,即在燃烧前中期(0~1500 ms),平均燃速为1.926 ms左右,而在燃烧后半段(1500~2200 ms),测量燃速达到5 ms左右,造成该现象的原因可能是燃烧后期推进剂在交变应变的作用下发生了整体解体.另一方面,在燃烧前半段,推进剂燃烧温度和CO_(2)浓度呈现周期性变化,且变化频率与交变应变相同.

In this study,an optical test chamber was developed to investigate the combustion behavior of solid propellant under mechanical strain.High-speed imaging and laser absorption spectroscopy(LAS)was adopted to analyze the burning rate,CO_(2) concentration and combustion temperature of AP-HTPB propellant in response to varying strains.Under static strain,a proportional increase in burning rate,CO_(2) concentration and temperature was observed within a strain range of-10%to 10%.The variation range for burning rate,CO_(2) concentration and temperature was 1.72—2.1 mm/s,0.138—0.165 cm,and 1490—1680 K,respectively.When subjected to oscil-lating strain,the propellant combustion displayed a two-stage pattern.The average burning rate was approximately 1.926 mm/s in the initial stage(0—1500 ms),which then surged to around 5 mm/s in the subsequentstage(1500—2200 ms),likely due to propellant decomposition.Additionally,both CO_(2) concentration and com-bustion temperature exhibited periodic fluctuations at the same frequency of the oscillating strain.