Mechanism of rock breaking by high voltage electric pulse liquid plasma shockwave breaking

The liquid-phase discharge plasma shock wave rock breaking is a novel technique based on the “liquid-electric effect,” featuring controllable energy output, operational stability, and low cost. In this study, a three-dimensional multi-physics coupling model was developed, incorporating five interrelated physical fields: electric circuit field, current field, heat transfer field, fluid dynamics, and solid mechanics. The model is governed by the laws of energy conservation, Maxwell's equations, conjugate heat transfer equations, and the Navier–Stokes equations, enabling detailed simulation of plasma channel formation and underwater shock wave propagation. The Mohr–Coulomb criterion was employed to evaluate rock failure behavior. To validate the accuracy of the simulation model, indoor experiments were conducted to elucidate the rock breaking mechanism of LPSB. Furthermore, a series of controlled experiments was conducted to investigate the influence of initial charging voltage and electrode spacing on rock-breaking efficiency. The optimal parameter ranges were determined to be 120 to 140 kV for charging voltage and 10 to 12 mm for electrode spacing. These findings provide both theoretical insight and experimental guidance for the advancement and engineering application of LPSB technology.