膏体燃气发生器启动特性研究

Study on Starts of Pasty Propellant Gas Generator

关键词:  膏体燃气发生器  膏体火箭发动机  多次启动  内弹道  燃烧震荡

Key words:  Pasty propellant gas generator  Pasty propellant rocket  Multiple starts  Internal trajectory  Combustion oscillation

摘要:

设计了一套膏体燃气发生器，进行了膏体燃气发生器启动试验，包括膏体燃气发生器流量实验，单次和重复启动试验，以研究基于气源供给方式的流量可调膏体燃气发生器启动特性，探索使用黑火药点火和热流挂管余热重复启动方案的可行性及其对内弹道特性的影响。结果表明膏体燃气发生器单次和重复启动效果良好，单次启动试验验证了燃烧室压力受供给流量控制，可实现推力可调，燃烧室工作压力分别为1.2MPa和1.9MPa，重复启动试验验证了重复启动方案的可行性，重复启动间隔8s；由于膏体推进剂剪切稀化的特性导致膏体燃气发生器内弹道曲线呈缓慢向上爬升趋势，点火初期燃速与燃烧室压力匹配过程会出现振荡燃烧现象；膏体推进剂中的气泡以及工作过程中反向传热均对内弹道特性产生影响；膏体燃气发生器燃面位置和燃面大小的控制仍为膏体燃气发生器启动过程中的一系列难点。

Abstract:

A pasty propellant gas generator was designed and a relatively complete start-up test was finished with it， including the determination of average flow rate of the gas generator， single and repeated start test. The purpose was to study the start-up characteristics of the flow adjustable paste gas generator based on gas pressure driven. The feasibility of using black powder ignition and repeating start-up with heat pipe， and its influence on the interior ballistic characteristics were explored. The results show that the paste gas generator has a good single and repeated start-up effect. The single start test verifies that the combustion chamber pressure was controlled by the propellant flow rate， and the thrust could be adjusted by it， and the working pressure of the combustion chamber is 1.2MPa and 1.9MPa. The repeated start test verified the feasibility of the scheme， and the shutdown time was 8s. It was found that the characteristics of shear-thinning of pasty propellant results in a slow upward trend in the internal ballistic curve. At the beginning of the start-up， combustion oscillation was found in combustion chamber during the matching process of burning rate and combustion chamber pressure. The bubble in the pasty propellant caused a certain pressure fluctuation on the internal trajectory and the pasty propellant rheological characteristics were affected by the heat transfer. The control of the position and size of the burning surface area is still a series of difficulties of the pasty propellant gas generator starts.