气氧/甲烷液体火箭发动机纵向不稳定燃烧机理研究  

Mechanism of longitudinal combustion instability in an O_(2)/CH_(4) liquid rocket engine

作　　者：聂万胜 郭康康 陈朋 钟战 刘瑜 苏凌宇 NIE Wansheng;GUO Kangkang;CHEN Peng;ZHONG Zhan;LIU Yu;SU Lingyu(Department of Aerospace Science and Technology,Space Engineering University,Beijing 101416,China;Faculty of Mechanical Engineering and Mechanics,Ningbo University,Ningbo 315211,China)

机构地区：[1]航天工程大学宇航科学与技术系,北京101416 [2]宁波大学机械与力学学院,浙江宁波315211

出　　处：《推进技术》2024年第7期102-112,共11页Journal of Propulsion Technology

基　　金：国家“973”计划(613193)。

摘　　要：为研究同轴剪切喷嘴液体火箭发动机的高频不稳定燃烧诱发机理,针对单喷嘴气氧/甲烷缩尺火箭发动机开展了热试车试验和基于URANS/LES的高保真数值模拟。热试车试验得到了可重复的一阶纵向高频不稳定燃烧,数值模拟再现了试验中的不稳定燃烧,数值结果与试验结果符合良好。数值结果表明:燃烧室突扩面处的周期性涡脱落是引发、维持不稳定燃烧的激励源。整个热声振荡过程中,压力与释热率保持同步振荡,不断有能量从燃烧过程进入声场以维持纵向热声振荡,形成“燃烧-声学-流动”的能量反馈回路。周期性涡脱落本质上起到了释热相位延迟的作用,成为“燃烧-声学-流动”能量反馈回路的驱动源。In order to study the high-frequency combustion instability triggering mechanism in a liquid rocket engine with coaxial shear injector,the hot-fire test and high-fidelity numerical simulation based on URA-NS/LES were carried out for a single injector O_(2)/CH_(4) sub-scale liquid rocket engine.The hot-fire tests obtained the repeated first-order longitudinal high frequency combustion instability.The numerical simulation reproduced the first-order longitudinal high frequency combustion instability of the tests,and the numerical results and the test results agree well.The numerical results show that the periodic vortex shedding at the combustor dump plane is the source for triggering and maintaining combustion instability.During the thermo-acoustic oscillation pro-cess,the pressure and heat release rate oscillate in-phase,there is constant energy from the combustion process fed to the acoustic field to maintain longitudinal thermo-acoustic oscillation,forming a‘combustion-acoustic-hy-drodynamic’energy feedback loop.Periodic vortex shedding essentially plays a role in heat release phase delay,becoming the driving source of the‘combustion-acoustic-hydrodynamic’energy feedback loop.

关 键 词：缩尺液体火箭发动机 纵向不稳定燃烧 热试车试验 数值模拟 涡脱落 

分 类 号：V434.3[航空宇航科学与技术—航空宇航推进理论与工程]