高可控非稳态对冲扩散火焰的实现及其时变流场特征  

Realization and Flow Field Characterization of Highly-Controllable Unsteady Counterflow Diffusion Flames

作　　者：余超[1] 李国柱 周梦祥 王宇[1,2] YU Chao;LI Guozhu;ZHOU Mengxiang;WANG Yu(School of Automotive Engineering,Wuhan University of Technology,Wuhan 430070,China;Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan 430070,China)

机构地区：[1]武汉理工大学汽车工程学院,武汉430070 [2]先进汽车零部件技术湖北省重点实验室,武汉430070

出　　处：《西安交通大学学报》2023年第2期49-56,共8页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51976142)。

摘　　要：为研究火焰拉伸变化对流场、碳烟生成的瞬态效应,进一步完善层流火焰面模型在湍流火焰中的应用,设计并搭建了一个高可控的声激励对冲火焰燃烧器及其流场和碳烟浓度场的测量系统,利用相位锁定的粒子图像测速和激光诱导白炽光技术,测量了简谐振荡的对冲火焰中流场以及碳烟生成随时间的变化特性。结果表明:设计的声激励对冲燃烧器喷嘴出口速度为非均匀分布;非稳态工况下,施加的声激励电压信号幅值与出口速度振幅呈线性关系,频率为40 Hz的乙烯和丙烷火焰出口速度分别滞后电压信号0.09、0.14周期;随着电压信号频率的增加,速度的滞后程度也随之扩大。此外,40 Hz频率下乙烯火焰的碳烟体积分数滞后准稳态值0.35周期,具有明显的瞬态效应。研究成果可为非稳态层流火焰面模型开发提供理论依据。In order to investigate the transient effect of flame stretch on flow field and soot formation,and to further improve the application of laminar flamelet model in turbulent flame,a highly-controllable acoustically-excited counterflow flame burner with flow field and soot concentration field measurement system is designed and established.Using phase-locked particle image velocimetry(PIV)and laser-induced incandescence(LII)technologies,the characteristics of the flow field and soot formation with time in counterflow flames with harmonic oscillation are measured.The results show that the exit velocity profile at the nozzle of the acoustically-excited counterflow burner is non-uniform.Under unsteady conditions,the amplitude of the applied acoustic excitation voltage signal has a linear relationship with the exit velocity amplitude.At a frequency of 40 Hz,the ethylene and propane flame’s exit velocities lag behind the voltage signal by 0.09 and 0.14 cycles,respectively.As the frequency of the voltage signal increases,the lag of the velocities expands.In addition,the soot volume fraction of ethylene flame at 40 Hz lags behind the quasi-steady value by 0.35 cycles,which exhibits obvious transient effects.The research results provide a theoretical basis for the development of unsteady laminar flamelet model.

关 键 词：声激励 对冲燃烧器 碳烟生成 粒子图像测速 激光诱导白炽光 

分 类 号：TK16[动力工程及工程热物理—热能工程]