常温推进剂发生器低压点火动态特性分析  

Transient characteristic analysis of low-pressure ignition for normal-temperature propellant generator

作　　者：王丹 刘臻丽 周康 陈宏玉[1] 刘占一[1] 李舒欣 WANG Dan;LIU Zhenli;ZHOU Kang;CEHN Hongyu;LIU Zhanyi;LI Shuxin(Xi'an Aerospace Propulsion Institute,Xi'an 710100,China)

机构地区：[1]西安航天动力研究所,陕西西安710100

出　　处：《火箭推进》2023年第2期35-41,共7页Journal of Rocket Propulsion

基　　金：国家青年科技基金(11702204)。

摘　　要：针对常温推进剂富氧燃气发生器低压点火室压存在低工况建压缓慢的问题,提出一种基于推进剂转化率修正系数的修正方法。该方法将抛物线函数和双曲正切函数结合,形成新的修正系数函数,以燃气发生器混合比下降至临界混合比时刻作为修正系数函数切换点。经不同点火时序低压点火试验验证,仿真模型计算获得的燃气发生器室压与试验值最大动态误差为4.6。采用混合比36为临界混合比,可以在较宽的范围内准确捕捉到推进剂开始正常燃烧的时间点。富氧燃气发生器中若提前进入过多氧化剂会导致大量积存,将与其后进入而不断累积的燃料瞬间发生剧烈化学反应导致室压出现超调峰值,在时序设计中应在保证富氧点火的前提下尽可能缩短燃料与氧化剂进入的时差。To solve the problem that the low-pressure ignition chamber pressure builds up slowly in the oxygen-enriched generator with normal-temperature propellant,a modified method based on the correction coefficient of propellant conversion rate is proposed.This method combines the parabola function and the hyperbolic tangent function to form a new correction coefficient function,and it takes the time when the mixing ratio of generator decreases to the critical mixing ratio as the switching point of the correction coefficient function.The results,verified by the low pressure ignition test with different ignition sequences,show that the maximum dynamic error of the generator chamber pressure between the simulated results and the test value is 4.6.Using the mixing ratio of 36 as the critical mixing ratio,the time point of normal combustion of propellant can be accurately captured in a wide range.If the oxidant in the oxygen-enriched generator accumulates too much in advance,a sharp chemical reaction will take place in the generator after fuel enters and it will lead to a peak overshoot in the chamber pressure.For the design of time sequence,the time lag between the fuel and the oxidizer should be shortened as far as possible on the premise of ensuring the oxygen-enriched ignition.

关 键 词：燃气发生器低压点火 动态特性分析 转化率修正 系统动力学仿真 临界混合比 

分 类 号：V434[航空宇航科学与技术—航空宇航推进理论与工程]