摘要
针对不稳定热释放与声场耦合而产生的热声振荡现象,严重影响燃烧系统的稳定性和振动噪声水平的问题,本文提出一种有效的热声耦合振荡抑制策略。本文基于能量原理和声压连续条件建立了周期分布局域共振薄膜结构-管腔-火焰耦合模型,研究了薄膜结构对管腔热声耦合系统热、声模态稳定性的抑制作用,并揭示了周期结构声学带隙对系统模态稳定性的影响规律。结果表明:薄膜结构可实现管腔耦合系统的多模态不稳定性抑制,尤其对声模态特征有显著的干涉作用。此外,可以发现热声耦合系统特征根分布受声学带隙影响较大,部分模态急剧向低频偏移,且所研究频段范围内模态稳定性均得到了改善,充分说明了本文所提出周期性局域共振薄膜在热声耦合不稳定性抑制方面的有效性。
Thermoacoustic oscillation caused by the coupling of unstable heat release and acoustic field greatly influences the stability and vibration/noise level of a combustion system.Therefore,an effective strategy is proposed in this paper to control thermoacoustic oscillation.The coupling model of periodic resonant membrane structure-duct-flame is established based on the energy method and the sound pressure continuity condition.The suppression effect of the membrane structure on the thermal/acoustic modal stability of a duct thermoacoustic coupling system is studied.Further,the influence law of periodic structure acoustic bandgap on modal stability is revealed.Results show that multimodal instability can be suppressed by introducing the membrane structure,especially for the acoustic mode.Additionally,the characteristic root distribution of the thermoacoustic coupling system is remarkably affected by the acoustic bandgap,and some modes show a sharp shift toward a low frequency.Modal stability can be improved for all modes within the scope of the frequency band presented herein in the presence of a periodic membrane.Therefore,the proposed periodic locally resonant membrane effectively suppresses the thermoacoustic coupling instability.
作者
刘杨
陈京圳
杜敬涛
LIU Yang;CHEN Jingzhen;DU Jingtao(College of Power and Energy Engineering,Harbin Engineering University,Harbin 15001,China)
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2022年第9期1265-1270,共6页
Journal of Harbin Engineering University
基金
国家自然科学基金青年基金项目(12102101)
国家自然科学基金面上项目(11972125)。
关键词
热声耦合
模态稳定性
多模态
局域共振薄膜
周期结构
声学带隙
系统特征根
不稳定性抑制
thermoacoustic coupling
modal stability
multimodal
locally resonant membrane
periodic structure
acoustic bandgap
system characteristic root
instability suppression
