[关键词]
[摘要]
以甲烷为燃料,在以GE燃机6B喷嘴为基础的1/3模型燃烧室中,研究了燃烧室空气流量和当量比的变化对燃烧自激振荡的压力波动的影响,以及燃烧发出的音频信号的特征。实验结果显示:在3组不同的入口空气流量工况下,随着当量比的增加,燃烧室的稳定——自激振荡——稳定工作的变化趋势保持一致;在不同的流量下,当量比=0.61的工况产生了最强烈的自激振荡,同时振荡的压力波动幅值和频率随燃烧室入口空气流量的增加而增大;通过FFT(快速傅里叶变换)计算发现,在有明显自激振荡的工况中,动态压力与音频信号的幅值均大幅超过稳定燃烧的工况,同时音频信号的一个特征频率与动态压力信号的特征频率重合。
[Key word]
[Abstract]
This paper studied the influence of air flow rate and equivalence ratio on self-excited oscillation and sound characteristic in a 1/3 scaled model combustor based on GE6B combustor using CH4 as fuel. The experiment results show that the trend of stable -- self-excited oscillation -- stable combustion keeps with the increasing of equivalence ratio in 3 test groups of different inlet air flow rate working conditions. The strongest oscillation appears in the conditions of equivalence ratio = 0.61 in every test group. The amplitude and frequency of oscillation increase with the raise of inlet air flow rate. According to the FFT analysis, the amplitude of the dynamic pressure inside the combustor and the sound signal outside the combustor in oscillation conditions are obviously exceed which in stable combustion conditions. And in oscillation conditions there must be one characteristic frequency of sound signal in agreement with the frequency of dynamic pressure.
[中图分类号]
TK471
[基金项目]