直流均匀场中球形金属微粒与电极碰撞的超声特性研究

Ultrasound Characteristics of Impact Between Spherical Metal Particles and Electrode in DC Uniform Field

GIL中金属微粒与电极碰撞时会产生超声信号,研究超声特性对微粒运动的在线监测具有重要意义。搭建了直流电压下平行板电极中球形金属微粒运动的实验平台,实验得到了不同电压、直径下铝微粒与低压极板碰撞时的超声信号,并通过编制计算机程序提取了超声信号的幅值,超声信号幅值结果表明:同等条件下,随着电压、微粒直径的增大超声信号幅值增大。基于Ansys/LS-DYNA建立了铝微粒与电极碰撞的力学模型,仿真获得了微粒与电极碰撞过程中接触力变化,仿真结果表明:碰撞过程中接触力呈先增大后减小趋势,存在最大值。最后,对接触力最大值与超声信号幅值之间的相关分析表明:接触力最大值与超声信号幅值之间成正比关系。

To investigate the ultrasound produced by the impact between spherical metal particles and electrode in DC GIL for online monitor of spherical metal particle motion, an experimental platform was set up for spherical metal particle motion in parallel plate electrodes under DC voltage. The ultrasonic signals generated by the impact between the aluminum particles and low-voltage electrode were obtained in the conditions of different voltage and particle sizes. And the amplitudes of the ultrasonic signals were extracted by the self-coded computer program to show that the amplitude increases with the augmentation of voltage and particle size under same condition. A mechanical model of the impact between the aluminum particles and the electrodes was established based on Ansys/LS-DYNA, hence the change of contact force during the impact process was achieved. Simulation illustrated that the contact force first increases and then decreases, thus a maximum value exists. At last, the correlation between the maximum contact force and the amplitude was analyzed, and it was shown that the maximum contact force is proportional to the amplitude.