火灾是最普遍地威胁国民经济和人民生命财产安全的主要灾害之一，在火灾救援过程中常规灭火技术存在造成二次损失的缺点。近几年一种成本低、免充装且避免二次损失的声波灭火技术被广泛关注。目前，关于声波扰动下可燃物燃烧的研究较少，且大部分集中在预混火焰、燃料熔滴火焰或油池火焰，而声波对固体火焰的影响及扑救固体火的可行性和实验研究相对较少。因此，本文开展声波对可炭化固体燃烧特性和火焰熄灭特性的影响，有利于完善声学灭火技术的科学框架。

本文自主搭建声波灭火系统平台，并采用该系统研究声波扰动下的木材燃烧特性和火焰熄灭特性。基于多通道信号分析仪，测量了不同工况下声波灭火系统产生的声场压力分布；利用高精度电子天平，得到了声波作用下木材燃烧火焰的质量损失变化规律，为进一步探究声波扰动对木材燃烧特性的影响机制，通过摄像机记录了声波作用下木材燃烧火焰的形态特征、火焰传播特性和熄灭特性；通过对不同工况下声波对木材燃烧火焰的熄灭效果分析，确定了声波灭火系统熄灭木材火焰的临界参数。

研究表明，该声波灭火系统产生的声压随横向声源距离的增加呈指数型衰减，在竖直平面产生的声压分布并非呈现中心对称规律，同时声压随声源功率的增加而增大，其频率响应在30Hz~70Hz时相对稳定；在声波作用下，木材的质量损失速率相较于自然燃烧状态减少值高于50%时，火焰熄灭；随着声源距离的降低或声频率的降低，声波对木材火焰的熄灭效果显著，火焰对声波的响应包括驻留后熄灭、传播后熄灭和可持续传播三种行为；研究发现，高声源功率、低声波频率对声波熄灭木材火焰的效果显著，但受限于声源距离或倾斜角度，研究对优化声波灭火系统和完善声波灭火理论具有指导意义。

Fire is one of the most common disasters that threaten the national economy and people's life and property safety. In recent years, an acoustic fire extinguishing technology with low cost, no charge and avoiding secondary loss has been widely concerned. Acoustic fire extinguishing technology combined with UAV technology has gradually become the evolution direction of fire fighting technology. At present, most of the research objects about the effect of acoustic wave on the combustion behavior of combustible are focused on the fuel droplet flame, oil pool flame or premixed flame, while the effect of acoustic wave on solid flame and the feasibility and experimental research of solid fire suppression are relatively few. Therefore, it is beneficial to perfect the scientific framework of acoustic fire extinguishing technology to study the influence of acoustic wave on wood combustion characteristics and flame spread and determine the parameters of acoustic fire extinguishing.

In this paper, a kind of acoustic fire extinguishing system is developed, which is used to study the wood burning and flame extinguishing characteristics under acoustic disturbance. The pressure distribution of sound field produced by acoustic fire extinguishing system under different working conditions is measured by using multi-channel signal analyzer. The mass loss of wood burning flame under acoustic wave was measured by high-precision electronic balance, and the influence mechanism of acoustic wave on wood burning characteristics was explored. The morphological characteristics, flame propagation characteristics and extinction characteristics of wood burning flame under acoustic wave were recorded by camera. The critical parameters of acoustic fire extinguishing system were determined by analyzing the extinguishing effect of acoustic wave on wood fire under different working conditions.

Studies have shown that the sound pressure of the acoustic extinguishing system decreases exponentially with the increase of the distance from the transverse sound source. The distribution of sound pressure generated in the vertical plane does not show the law of center-symmetry, and the sound pressure increases with the increase of sound source power, and its frequency response is relatively stable at 30Hz~70Hz. Under the action of acoustic wave, when the wood mass loss rate decreases by more than fifty percent compared with the natural combustion state, the flame goes out. With the increase of sound source distance or sound frequency, the extinguishing effect of acoustic wave on wood flame is weakened. The response of flame to acoustic wave includes three behaviors: quenching after residence, quenching after propagation and sustainable propagation. It is found that high acoustic source power and low acoustic frequency have a significant effect on wood flame suppression by acoustic wave, but are limited by acoustic source distance or tilt Angle. The research has a certain guiding significance for revealing acoustic fire extinguishing mechanism and optimizing acoustic fire extinguishing system.

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