横纵向声场作用下预混火焰非线性热声响应  

Nonlinear thermoacoustic response of premixed flames under longitudinal and transverse acoustic fields

作　　者：罗赛 王子璇 王鹏程 张思懿 李敬轩 LUO Sai;WANG Zixuan;WANG Pengcheng;ZHANG Siyi;LI Jingxuan(School of Astronautics,Beihang University,Beijing 100191,China;School of Energy and Power Engineering,Beihang University,Beijing 100191,China;National Key Laboratory of Aerospace Liquid Propulsion,Xi'an 710075,China)

机构地区：[1]北京航空航天大学宇航学院,北京100191 [2]北京航空航天大学能源与动力工程学院,北京100191 [3]航天液体动力全国重点实验室,陕西西安710075

出　　处：《火箭推进》2025年第1期93-101,共9页Journal of Rocket Propulsion

基　　金：国家自然科学基金(52376089);国家自然科学基金青年学生基础研究项目(523B2063);北京市自然科学基金(L241003)

摘　　要：液体火箭发动机燃烧室中,除了常见的纵向不稳定燃烧模态外,还存在更为复杂的横向不稳定燃烧模态。然而,现有基础研究主要集中于纵向声波模态,对横向声波模态的研究相对较为薄弱。因此,深入探究火焰在横向声波模态下的响应特性具有重要意义。为此,构建了一种能够模拟横向声波模态的矩形燃烧室,通过实验对比不同喷嘴长度(厚度)条件下,层流锥形预混火焰在横向同相外激和纵向外激作用下的火焰描述函数及火焰形状的动态响应特性。实验结果表明,尽管横向同相外激与纵向外激的火焰描述函数整体趋势相近,但在约140 Hz处,横向同相外激的火焰描述函数出现了显著峰值。这表明在该特征频率下,除了纵向压力脉动外,横向速度脉动也显著作用于锥形层流火焰,激发了更强烈的热释放率脉动。In the combustion chamber of liquid rocket engines,besides the common observed longitudinal combustion instability mode,more complex transverse instability modes also exist.However,current fundamental research predominantly focuses on longitudinal acoustic modes,with relatively limited studies on transverse acoustic modes.Therefore,it is important to explore the response characteristics of flames under transverse acoustic modes.To address this,a rectangular combustion chamber capable of simulating transverse acoustic modes was constructed.With varying nozzle lengths(thicknesses),experiments were conducted to compare the dynamic response of the flame describing function(FDF)and flame shape of laminar conical premixed flames under transverse in-phase excitation and longitudinal excitation.The experimental results indicate that although the overall trends of the flame describing function under transverse in-phase excitation and longitudinal excitation are similar,a distinct peak appears around 140 Hz for transverse in-phase excitation.This indicates that at this characteristic frequency,in addition to longitudinal pressure oscillations,transverse velocity oscillations significantly affect the laminar conical flame,leading to more intense heat release rate oscillations.

关 键 词：不稳定燃烧 火焰描述函数 层流预混火焰 横向模态 纵向模态 

分 类 号：V430[航空宇航科学与技术—航空宇航推进理论与工程]