Electronegative microchannel guided streamer propagation for in-liquid spark breakdown applications

Hwi-Chan Ham,Jack J Yoh

doi:10.1063/5.0042591

Abstract

One of the well-known challenging issues of in-liquid spark breakdown is electrode wear and wear-dependent deposit energy fluctuation, regardless of the electrode materials. This work suggests a method that can reduce the breakdown threshold by an order of magnitude and hence enhances the likelihood of breakdown, regardless of wear. Generally, the negative streamer propagates in a branching way; however, the present experiment indicates that the electronegative microchannel is converged with the streamer propagation and extends the breakdown gap distance between the electrodes. Subsequently, the breakdown-possible gap distance was extended by 14.3 times, leading to an enhancement of shockwave intensity by 33%. Such an extension of the breakdown conditions was achievable without any additional source energy input or changing the substance of dielectric electrodes. Thus, the results provide a favorable scheme for energy reduction in high-voltage systems, cost saving for electrode replacement, and enhancement of the propagating shock pressure.

Highlights

The questions arise considering the breakdown mechanism based on the Bubble theory
The negative streamer propagates in a branching way; the present experiment indicates that the electronegative microchannel is converged with the streamer propagation and extends the breakdown gap distance between the electrodes
If the streamer path between the electrodes is filled with a stack of microbubbles, named “microchannel” along the propagation path, would it guide the streamer propagation? What type of substance for microchannel is the most suitable for efficient streamer propagation? In this work, we used the gaseous microchannel with electronegative behavior that guides and improves the streamer propagation

Summary

Introduction

The questions arise considering the breakdown mechanism based on the Bubble theory. If the streamer path between the electrodes is filled with a stack of microbubbles, named “microchannel” along the propagation path, would it guide the streamer propagation? What type of substance for microchannel is the most suitable for efficient streamer propagation? In this work, we used the gaseous microchannel with electronegative behavior that guides and improves the streamer propagation. The negative streamer propagates in a branching way; the present experiment indicates that the electronegative microchannel is converged with the streamer propagation and extends the breakdown gap distance between the electrodes.

Results

Conclusion