浮力扩散火焰对低频外加声场的响应特性

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...

Response of Buoyant Diffusion Flame to the Low-frequency Sound

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.