不均匀电场下水中脉冲放电观测及沉积能量对激波的影响

Observation of Underwater Pulse Discharge and Influence of Deposited Energy on Shock Wave in Non-uniform Electric Field

为了探究沉积能量对水中脉冲放电产生激波的影响。该文建立了水中脉冲放电试验平台,研究了间隙电压为30k V,间隙距离为15mm,针–针电极条件下不均匀电场中的水中脉冲放电。采用高速摄像机对水中脉冲放电过程进行了光学观测,并结合激波压强、电弧电压、电流等测量参量对电弧、气泡形态与运动变化规律进行了综合分析。为了研究沉积能量对激波的影响,提出了时变电弧阻抗条件下沉积能量与电弧平均电阻的计算方法,分析了每个半周期沉积能量与电弧平均电阻的变化,给出了沉积能量与激波压强峰值的关系表达式。所得结论能促进对水中脉冲放电激波的产生机理的认识,以便实现更高的激波强度。

In order to study the influence of deposited energy on the shock wave induced by underwater pulse discharge. An experimental system for underwater pulse discharge in non-uniform electric field was established. The needle-needle electrode system was used, and the gap distance was 15mm. The charged voltage of the main capacitor was 30kV. A fast camera was used for the observation of the motion and shape variation of the arc and bubble, and the results are analyzed comprehensively. In order to study the influence of deposited energy on the shock wave induced by the underwater pulse discharge, the calculation of the deposited energy and the average arc resistance was proposed. In the calculation, the time-varying characteristic of the arc impedance was taken into consideration. Finally, the variations of the deposited energy and the average arc resistance at every half-period were shown, and the expression between the deposited energy and the peak value of the shock wave was given. The results may be valuable to the research on the physical mechanism of underwater pulse discharge, which is crucial to the generation of stronger shock wave.