液氧煤油火箭发动机不稳定燃烧过程的数值分析

摘要

采用欧拉-拉格朗日方法对液氧煤油发动机燃烧室内的两相燃烧过程进行数值模拟,在验证模型可靠性基础上,分析无隔板工况下自激l阶切向高频不稳定性燃烧出现的原因.结果表明:喷嘴间雾化锥发生相互干涉使得推进剂空间分布不均,导致脉动释热,同时燃烧室内无隔板时横向压力波阻尼特性降低,使得燃烧室内出现1阶切向燃烧不稳定性;在不稳定燃烧过程中,压力振荡波形和频率与释热波动的波形和频率产生耦合,耦合程度越高,所舍释热波峰峰值数量越少,其振荡幅值也将越大.%Numerically simulated thetwo-phase reacting process in LOX/Kerosene Rocket Engine combustion chamber by using Eulerian-Lagrangian method,after verified the validity of the model,analyzed the reason why the self-triggered first-order tangential high frequency instability combustion show up when there is no baffle.The result indicates:the mutual interference of atomizing cone between injectors makes the unevenly distributed in space,that leads to pulsation heat release,meanwhile the damping characteristics is lower when there is no baffle in the chamber,leads to the first-order tangential high frequency instability combustion in the chamber;In the instability combustion,pressure oscillation waveform and frequency couple with heat release oscillation waveform and frequency,the higher the degree of coupling is,the less number of the peak heat release wave crest contain,the oscillation amplitude will be higher.