Influence of hydrostatic pressure on underwater explosion bubble-plate interaction

This study examines the impact of hydrostatic pressure on the dynamics of underwater explosion bubbles near a steel plate through numerical and experimental studies. We conduct underwater explosion experiments in a pressure tank, altering the air pressure within the tank using a pressure pump to change the hydrostatic pressure around the bubbles. The interaction between the bubbles and the plate is recorded with a high-speed camera, and we extract and analyze the jet velocity, bubble radius, and plate displacement as functions of hydrostatic pressure. Building on this, we design a numerical framework that encompasses hydrostatic pressures varying from 0.2 MPa to 20 MPa and dimensionless bubble-plate standoff parameters $\gamma$ from 0.6 to 2.5 for a more thorough investigation on the bubble-plate interaction. We find that both the maximum jet velocity and the maximum jet volume exhibit scaling relationships with hydrostatic pressure $p_{\infty }$ when $p_{\infty }>1$ MPa. Additionally, the dimensionless maximum jet volume shows a non-monotonic relationship with $\gamma$, depending on the degree of bubble-plate interaction at the moment of jet impact. Across a certain span, the maximum plate displacement also follows a scaling relationship with $p_{\infty }$, where the exponent differs according to $\gamma$. This work is intended to offer a foundation for the study of underwater explosion bubble dynamics and fluid–structure interaction characteristics under high hydrostatic pressure or deep water environments.