速度扰动对自激振荡火焰流–热–声动态特性影响试验研究  

Experimental Study on the Effect of Velocity Fluctuation on Flow and Thermoacoustic Dynamic Characteristics of a Self-excited Instability Flame

作　　者：金明 李原森 陆羽笛 柳伟杰 葛冰[1] 臧述升[1] JIN Ming;LI Yuansen;LU Yudi;LIU Weijie;GE Bing;ZANG Shusheng(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Aero-Engine Academy of China,Aero Engine Corporation of China,Beijing 101304,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]中国航空发动机集团,中国航空发动机研究院,北京101304

出　　处：《工程热物理学报》2024年第6期1615-1624,共10页Journal of Engineering Thermophysics

摘　　要：为分析燃烧器入口速度扰动频率对自激振荡燃烧的影响,掌握速度扰动抑制自激振荡燃烧的方法。通过试验研究了速度扰动频率对自激振荡燃烧条件下流–热–声动态特性的影响规律。试验在常温常压下进行,燃烧器入口平均速度u=10.1m/s,速度扰动幅值u′/u=10%,速度扰动频率范围55~235 Hz。利用光电倍增管和脉动压力传感器测量全局火焰热释放率和脉动压力动态特性,采样率为20 kHz;采用高频PIV测量流场动态特性,采样率为1 kHz。结果表明在自激振荡燃烧条件下,流–热–声不稳定模态频率相同,多物理场耦合驱动自激振荡燃烧;在速度扰动与自激振荡燃烧耦合时,速度扰动频率近似等于自激振荡频率或倍频时,自激振荡燃烧受到抑制,而在其他速度扰动频率下,自激振荡仍占据主导。当受迫燃烧斯特劳哈尔数St_(f)远小于自激振荡燃烧斯特劳哈尔数St时,主燃级射流外剪切层大尺度旋涡仍存在,且旋涡脱落频率仍等于自激振荡频率;而St_(f)近似等于或大于St时,大尺度旋涡随着St_(f)增大而逐渐减少,且旋涡脱落频率等于速度扰动频率。In order to analyze the influence of inlet velocity perturbation frequency on self-excited instability combustion and to understand the methods of suppressing self-excited instability com-bustion by velocity perturbation,the impact of velocity perturbation frequency on the fow-thermal-acoustic dynamic characteristics under self-excited instability combustion conditions was experimen-tally investigated.The experiments were conducted at room temperature and atmospheric pressure,with an inlet bulk velocity of 10.1 m/s,a velocity perturbation amplitude of 10%,and a velocity perturbation frequency range of 55 Hz to 235 Hz.The global flame heat release rate and pressure dynamic characteristics were measured using a photomultiplier tube and dynamic pressure sensor,with a sampling rate of 20 kHz.High-frequency PIV was used to measure the flow field dynamic characteristics,with a sampling rate of 1 kHz.Under the condition of self-excited instability com-bustion,the unstable frequencies of the flow-thermal-acoustic were the same,driving the self-excited instability combustion through multi-physical field coupling.When velocity perturbation was cou-pled with self-excited instability combustion,the velocity perturbation frequency was approximately equal to the self-excited instability frequency or its multiple,which inhibited self-excited instability combustion.However,at other velocity perturbation frequencies,self-excited instability combustion still dominated.When the forced combustion Strouhal number Stt was much smaller than the self-excited instability combustion Strouhal number St,the large-scale vortex of the main stage jet shear layer still existed and the vortex shedding frequency remained equal to the self-excited instability frequency.When St_(f) was approximately equal to or greater than St,the large-scale vortex grad-ually decreased with increasing St_(f),and the vortex shedding frequency was equal to the velocity perturbation frequency.

关 键 词：自激振荡燃烧 受迫燃烧 速度扰动频率 流动不稳定性 热声不稳定性 

分 类 号：TK477[动力工程及工程热物理—动力机械及工程]