浮力扩散火焰对低频外加声场的响应特性  

Response of Buoyant Diffusion Flame to the Low-frequency Sound

作　　者：熊才溢 刘彦辉 许沧粟 黄鑫炎[1] XIONG Cai-Yi;LIU Yan-Hui;XU Cang-Su;HUANG Xin-Yan(Research Centre for Fire Engineering,Hong Kong 999077,China;The Hong Kong Polytechnic University Shenzhen Research Institute,Shenzhen 518057,China;College of Energy Engineering,Hangzhou 310000,China)

机构地区：[1]香港理工大学消防工程研究中心,香港999077 [2]香港理工大学深圳研究院,深圳518057 [3]浙江大学能源工程学院,杭州310000

出　　处：《工程热物理学报》2022年第2期553-558,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.52006185)。

摘　　要：本文通过实验研究了浮力扩散火焰在外加声场作用下的响应行为和熄火机理。实验发现,声场中的气体燃料火焰熄火时,火焰处的声压与声频呈正相关。但该正比关系受火焰和环境等因素影响,无法精确判断熄火的临界条件。因此,本文基于火焰在声场中的偏移量脉动,为声场的临界灭火条件构造了数值判据。研究结果表明,该判据对目标火焰的依赖性较低,且在各熄火条件下为常量,可以有效评判外加声场的灭火能力。此外,本文还构造了火焰对外加声场的响应模型,揭示了低频外加声场利于灭火的机理,并推测扬声器音盆的脉动是引发熄火的主因。本研究为基于外加声场的灭火新技术提供科学指导。This work experimentally investigated the response of a buoyant diffusion flame to the external sound field.It was found that the sound pressure required for extinction correlates positively with the frequency used;however,the mechanism behind this correlation remains as a knowledge gap.Thus,this work proposed a model based on the acoustic-induced flame displacement,which helps formulate a criterion for predicting extinction.Results showed that the criterion could be a constant indicator for extinction.Moreover,this criterion can bridge the flame and sound,and it helps understand the extinguishing excellence of the low-frequency sound.Also,the motion of the speaker membrane was identified as the main factor that dominates extinction.This work can improve the understanding of flame dynamics under the external sound field,thus establishing a scientific framework for acoustic-based fire suppression technologies.

关 键 词：外加声场 低频纵波 灭火技术 熄火机理 火灾 

分 类 号：TK123[动力工程及工程热物理—工程热物理]