新型双旋流燃烧室热声振荡的实验研究

对一新型双旋流燃烧室开展了实验测量，研究了燃烧状态参数2种变化过程对火焰热声振荡特性的影响（过程1:保持甲烷体积流量不变，当量比从0.900逐步减小至0.725再逐步增大至0.925；过程2:保持当量比为0.850不变，逐步增大预混气的体积流量）。结果表明:在该燃烧室中存在M型和V型2种火焰结构；在过程1中，随着当量比减小，火焰由不稳定的M型转变为稳定的V型，其后，随着当量比增大，又逐渐转变为M型，存在明显的滞环现象；在过程2中，仅在初始流量下存在明显的热声振荡现象，随着流量增大，火焰变得稳定；基于压力脉动信号的功率谱特性分析和相空间重构分析，发现该双旋流燃烧室内热声振荡主频率分布于400.0和256.0 Hz左右。

Experimental investigation on thermoacoustic oscillation of a new dual-swirl combustor

In this paper, a new type of dual-swirl combustor is tested. The effects of two varying processes of combustion state parameters on the thermoacoustic oscillation characteristics of flame are studied. The two processes are: keep methane volume flow rate constant and reduce the equivalence ratio from 0.900 to 0.725 and then increase it back to 0.925; keep the equivalence ratio constant as 0.850 and increase the premixed gas volume flow. The results show that there are two distinct flame patterns of M-shaped and V-shaped in this combustor. In process 1, the flame changes from unstable M-shaped flame to stable V-shaped flame with decreaseing equivalence ratio, and then changes to M-shaped flame with increaseing equivalence ratio, the combustor exists hysteresis phenomenon; In process 2, Thermoacoustic oscillation is only found at the initial flow rate, and the flame becomes stable with increaseing flow rate.Through the analysis of the power spectrum characteristics and phase space reconstruction of the pressure fluctuation signal, it is found that there are unstable frequencies around 400.0 and 256.0 Hz in this dual-swirl combustor.