The pulsation characteristics of bubble in deep water environments within limited water area

Abstract

The effect of hydrostatic pressure on bubble dynamics parameters was analyzed through a combination of experimental and numerical simulation methods in this paper. Under four operating conditions with initial pressures of 0.1, 0.25, 0.3, and 0.5 MPa, a high-speed camera was used to capture the underwater explosion bubble pulsation process of 0.3 g of Pentaerythritol Tetranitrate (PETN). The bubble pulsation process of the underwater explosion of 0.3 g of PETN was simulated with initial pressures ranging from 0.1 to 30 MPa using LS-DYNA software. Based on the simulation results, the variation patterns of (bubble pulsation period, maximum bubble radius, specific bubble energy, influence of a fixed planar boundary on bubble migration, and peak bubble pulsation overpressure) with hydrostatic pressure were obtained. The simulation results indicate that both the maximum bubble pulsation radius and pulsation period exhibited significant decreases as hydrostatic pressure increased, with measured decay coefficients of −0.361 and −0.817, respectively. The specific bubble energy and the overpressure peak of the bubble pulsation increased with increasing hydrostatic pressure, and the growth rate was faster within 1 MPa. When the initial pressure was 3.650–3.675 MPa, the bubble center remained stationary, with γ ranging from 10.82 to 10.86.