基于变分模态分解的燃烧室热声振荡衰减系数辨识  

Identification of attenuation coefficient for thermoacoustic oscillation in combustion chamber based on variational mode decomposition

作　　者：樊志伟 钟战 李庚 聂万胜 何博 FAN Zhiwei;ZHONG Zhan;LI Geng;NIE Wansheng;HE Bo(Department of Aerospace Science and Technology,Aerospace Engineering University,Beijing 101400,China)

机构地区：[1]航天工程大学宇航科学与技术系,北京101400

出　　处：《火箭推进》2023年第5期23-31,共9页Journal of Rocket Propulsion

基　　金：国家自然科学青年基金(12102482)。

摘　　要：利用发动机燃烧室稳定燃烧阶段的压力振荡信号,提取热声谐振模态频率及其幅值,并建立不同复杂程度热声振荡理论模型辨识获取各模态衰减系数,是当前试验评估燃烧室燃烧稳定性裕度的一种重要手段。建立了二阶随机振子热声振荡理论模型,采用基于最大峭度准则的变分模态分解算法提取压力振荡信号的热声谐振模态,开展了模态提取算法和时/频域辨识方法验证,并将其应用于某针栓式气氧/乙醇模型发动机燃烧稳定性裕度评估分析。结果表明:与传统的带通滤波算法相比,峭度最大变分模态算法有效提高了热声谐振模态的提取精度和使用便捷性。Based on the pressure oscillation signal of the stable combustion stage of the liquid rocket engine combustion chamber,extracting the thermoacoustic resonant mode frequency and its amplitude,and establishing the theoretical model of thermoacoustic oscillation of different complexity to identify and obtain the attenuation coefficients of each mode,is an important means to evaluate the combustion stability margin of the combustion chamber in current experiments.A theoretical model of thermoacoustic oscillation with a second-order stochastic oscillator is established,and the thermoacoustic resonant mode of the pressure oscillation signal is extracted by the steep maximum variational mode decomposition algorithm,and then the mode extraction algorithm and the time/frequency domain identification method are verified.In addition,it is applied to the combustion stability margin evaluation and analysis of a needle-bolt gas oxygen/ethanol model engine.The results show that compared with the traditional bandpass filtering algorithm,the steep maximum variational mode algorithm effectively improves the extraction accuracy and convenience of thermoacoustic resonant mode.

关 键 词：燃烧稳定性 衰减系数 系统辨识 谐振频率 滤波宽度 变分模态分解 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]