电弧产生声波的效应在科学研究和实际工程中有着大量应用，在近几十年来受到广泛的关注。本文围绕气体中电弧声波电声物理过程和基本特性，开展了如下的研究工作：为研究电弧声波的电声物理过程和基本特性，搭建了两个电弧声波实验平台。分别用于研究“纯交流电弧”声波和“直流偏置交变电弧”声波。并建立了一套电弧声波诊断系统，包括电参数（电流、电压）测量，电弧等离子体参数（温度、直径）测量，声波参数（声压、频谱）测量等。实验测量了电弧及声波相关物理量（电弧电流、电弧功率、电弧温度、电弧直径、电弧声压）随时间的变化过程，它呈现了一幅电弧产生声波的物理图像：电流向电弧注入能量，该能量的变化（即电弧功率）导致电弧温度的升降及电弧直径的胀缩，电弧声波随之产生。研究了电弧声波的电声特性，即电弧电流（交流分量幅值和频率）、电弧长度、测声距离对电弧声波的影响。发现电弧声波与电流交流分量幅值和频率成正比；电弧声波与长度成正相关，但不是正比关系，长电弧的发声效率要高于短电弧；发现电弧声波与测声距离成反比，说明电弧声波按球面波传播。研究了电弧声源辐射方向性，测量了声源辐射方向性图，表明电弧是单极性声源，证实了电弧产生声波的机制是“能量调制”而非“动量调制”，这与其他形式的放电等离子体有很大不同。建立了电弧声波的电-声联合仿真模型，第一步通过对电弧的数值模拟，计算电弧内能功率分布，这一项作为电弧发声的声源项；第二步通过对空间声场的数值模拟，计算出空间声压分布。比较了电-声联合数值模拟和传统基于声学公式的近似计算方法，验证了电-声联合数值模拟的准确性。研究了氩气、氦气和氮气三种气体电弧产生声波的特性。通过实验测量结果和数值模拟结果发现，三种电弧发声特性有很大不同。气体的电导率和热导率两个参数通过影响电弧电功率和沿阳极散热情况，从而决定电弧的发声特性。实验中还借助气体混合室，对于不同混合比的氩氦混合气和氩氮混合气进行了实验研究。
The phenomenon of acoustic waves produced by electric arcs has a large number of applications in scientific research and engineering applications. It has received extensive attention in recent decades. In this paper, the following research work is carried out around the physical process and basic characteristics of arc acoustic waves in gas:In order to study the electroacoustic physical process and basic characteristics of arc acoustic waves, two arc acoustic wave experimental platforms were built. They are used to study the sound waves of "pure AC arc" and "DC bias alternating arc" respectively. And established a set of arc acoustic wave diagnosis system, including electrical parameters (current, voltage) measurement, arc plasma parameters (temperature, diameter) measurement, acoustic wave parameters (sound pressure, frequency spectrum) measurement, etc.The experiment measured the arc and acoustic wave-related physical quantities (arc current, arc power, arc temperature, arc diameter, arc sound pressure) over time. It presents a physical image of the acoustic wave generated by the arc: the current injects energy into the arc. The change of energy (that is, the arc power) causes the rise and fall of the arc temperature and the expansion and contraction of the arc diameter, and the arc sound wave is generated accordingly.The electroacoustic characteristics of arc acoustic waves are studied, that is, the effects of arc current (AC component amplitude and frequency), arc length, and sound distance on arc acoustic waves. It is found that the arc acoustic wave is directly proportional to the amplitude and frequency of the AC component of the current; the arc acoustic wave is positively related to the length, but not proportional. The sound efficiency of a long arc is higher than that of a short arc; it is found that the arc acoustic wave is inversely proportional to the measured sound distance, indicating that the arc acoustic wave Propagate as a spherical wave.The radiation directivity of the arc sound source is studied, and the radiation directivity diagram of the sound source is measured. It shows that the arc is a unipolar sound source, which confirms that the mechanism of the arc to generate sound waves is "energy modulation" rather than "momentum modulation", which is different from other forms of discharge plasma.The electric-acoustic joint simulation model of arc acoustic wave is established. The first step is to calculate the internal energy and power distribution of the arc through the numerical simulation of the arc. This term is used as the sound source term of the arc sound; the second step is to calculate the sound pressure distribution through the numerical simulation of the spatial sound field. The electro-acoustic joint numerical simulation is compared with the traditional approximate calculation method based on the acoustic formula, and the accuracy of the electro-acoustic joint numerical simulation is verified.The characteristics of acoustic waves generated by three gas arcs, argon, helium and nitrogen, are studied. Through experimental measurement results and numerical simulation results, it is found that the three arc sound characteristics are very different. The two parameters of gas conductivity and thermal conductivity determine the sound characteristics of the arc by affecting the electric power of the arc and the heat dissipation along the anode. In the experiment, with the aid of a gas mixing chamber, experimental research was carried out on argon-helium mixed gas and argon-nitrogen mixed gas with different mixing ratios.
