Combustion of nitrate ester plasticized polyether propellants  

硝酸酯增塑聚醚(NEPE)推进剂燃烧的数值与试验研究

作　　者：Xiao-ting YAN Zhi-xun XIA Li-ya HUANG Xu-dong NA 

机构地区：[1]College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2020年第10期834-847,共14页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：Project supported by the National Natural Science Foundation of China(No.11572349);the Natural Science Foundation of Hunan Province(No.2018JJ3606),China。

摘　　要：Nitrate ester plasticized polyether(NEPE)is a kind of high-energy solid propellant that has both good mechanical properties and high specific impulse.However,its unique composition makes its combustion mechanism different from both double-base propellants and composite propellants.In order to study the combustion mechanism of NEPE propellants,we improved the free radical cracking model of previous research to make it capable of predicting the burning rate of NEPE propellants.To study the combustion characteristics and provide data support for the model,an experimental system was built and four kinds of NEPE propellants with different compositions and grain size distributions were tested.The results show that our modified model can reflect the combustion characteristics of NEPE propellants with an acceptable accuracy.The difference between the model and the experimental data is mainly caused by uncertain environmental factors and the ignorance of interactions between components.Both the experimental data and the results predicted by the model show that increasing the backpressure helps to increase the burning rate of NEPE propellants.Furthermore,the grain size of the oxidizer inside the NEPE propellant has a more severe impact on the burning rate but a lighter impact on the burning rate pressure exponent in comparison with the grain size of aluminum.For aluminum-free NEPE propellants,the reaction in the gas phase is dominant in the combustion process while adding aluminum into the propellant makes the solid phase dominant in the final stage.The combustion of fine aluminum particles near the burning surface generates heat feedback to the burning surface which evidently influences the surface temperature.However,the agglomeration of coarse aluminum particles has little effect on the burning surface temperature.目的:因NEPE推进剂具有独特的燃烧性能和燃烧机理,现有模型无法直接用于其燃烧相关研究。本文希望对现有模型进行改进,并基于自由基裂解模型建立一个计算NEPE推进剂燃速的模型,然后对NEPE推进剂燃烧进行观察和测量,研究其燃烧特性,以期为所建模型提供数据支持。创新点:1.基于自由基裂解模型,计算每种成分同时存在多种粒径分布的NEPE推进剂的燃速;2.建立试验系统,观察NEPE推进剂燃烧火焰形态。方法:1.通过理论推导,构建燃速与推进剂成分的粒径和含量以及燃烧室压强之间的关系,得到燃速计算公式(公式(1)–(10));2.利用建立的模型,计算四种不同粒径分布的NEPE推进剂在不同压强下的燃速,并与试验结果进行比较,验证模型的可行性(图7);3.建立试验系统,测量NEPE推进剂的燃速和燃面温度,并观察其燃烧火焰(图5和6),分析不同成分对燃烧的影响。结论:1.基于自由基裂解模型建立的燃烧模型可用于预测NEPE推进剂的燃速;2.铝颗粒的添加对NEPE推进剂的燃烧火焰形态和气相反应都有较大影响;3.氧化剂(高氯酸铵和奥克托今)颗粒的粒径对燃速的影响比铝颗粒的粒径对燃速的影响大,但对燃速压强指数的影响相对较小。

关 键 词：Nitrate ester plasticized polyether(NEPE)propellant COMBUSTION Free radical model Burning rate 

分 类 号：V41[航空宇航科学与技术—航空宇航推进理论与工程]