膏体推进剂火箭发动机点火特性

为研究膏体推进剂火箭发动机点火工作特性,推导了膏体推进剂燃面变化模型和各阶段燃面方程,编制了发动机点火特性参数计算程序,计算了不同输运管道孔径以及膏体推进剂初始堆积量下瞬态燃烧室压力。设计了膏体推进剂火箭发动机热试车试验系统,成功进行了点火试验,分析了膏体推进剂火箭发动机点火工作过程中四个阶段的特性。结果表明:燃烧室平均压强的计算结果与试验数据吻合较好,计算误差小于5.7%,该计算程序适用于膏体推进剂火箭发动机点火特性参数计算;膏体推进剂初始堆积量增加一倍,初始压力峰值平均增加42.8%;输运管道孔径减小60%,初始燃烧时间平均减小66.5%,余药燃烧时间平均下降26.1%。发动机点火试验时,减小膏体推进剂初始堆积量,可降低燃烧室初始压力峰、增大稳定燃烧时间,另外减小输运管道孔径,可明显增大发动机稳定燃烧时间。

Ignition Characteristics of Pasty Propellant Rocket Engine

In order to study the ignition operating characteristics of the pasty propellant rocket engine, the burning surface change model of pasty propellant was built, and regression equations of pasty propellant were deduced in each stage. The calculating procedure was programmed and the transient pressure of combustion chamber under different transport pipeline diameter and pasty propellant initial accumulation was calculated. Also, the ignition tests were carried out successfully based on a pasty propellant rocket launch test system, and the ignition characteristics of the rocket engine in each working stage were analyzed. Results show that the data calculated by the procedure are in good agreement with the experimental and the maximum absolute error are 5.7%. When the pasty propellant initial accumulation doubled, the initial pressure peak increases by 42.8%. Under the same condition, as the diameter of the pipeline decreases by 60%, the initial combustion time and residual combustion time decrease by an average of 66.5% and 26.1%. The initial pressure peak can be decreased and stable burning time can be increased by reducing the initial packing quantity of pasty propellant, in addition, the stable burning time can be increased apparently by reducing the diameter of transport pipeline.