Cavitation nanopore in the dielectric fluid in the inhomogeneous, pulsed electric fields

TL;DR

This paper investigates the formation and development of cavitation nanopores in dielectric liquids under nonuniform pulsed electric fields, highlighting the role of electric field gradients and proposing mechanisms for breakdown.

Contribution

It introduces a new understanding of nanopore growth and breakdown mechanisms in dielectric fluids subjected to pulsed electric fields, including estimations for different liquids.

Findings

Electric field gradients significantly influence nanopore rupture growth or collapse.

The proposed breakdown mechanism involves secondary ruptures near nanopore poles.

Estimations of nanopore extension times in water and oil are provided.

Abstract

This paper discusses the nanopores emerging and developing in a liquid dielectric under the action of the ponderomotive electrostrictive forces in a nonuniform electric field. It is shown that the gradient of the electric field in the vicinity of the rupture (cavitation nanopore) substantially increases and determines whether the rupture grows or collapses. The cavitation rupture in the liquid (nanopore) tends to stretch along the lines of the original field. The mechanism of the breakdown associated with the generation of secondary ruptures in the vicinity of the poles of the nanopore is proposed. The estimations of the extension time for nanopore in water and oil (polar and nonpolar liquids, respectively) are presented. A new mechanism of nano- and subnanosecond breakdown in the insulating (transformer) oil that can be realized in the vicinity of water microdroplets in modern nanosecond high-voltage devices is considered