Energy Release Mechanism of Underwater Implosion With Different Structural Bodies

Underwater implosion is typically accompanied by intense shock wave energy. The investigation of its energy release mechanism is crucial for structural safety protection, marine environmental monitoring, ocean acoustic field analysis, and energy utilization. This study systematically examines the underwater implosion behavior of structures with different shapes and constraint states based on computational fluid dynamics (CFD) simulation. Realistic water conditions such as compressibility, viscosity, and turbulence are considered for simulation reliability guarantee. Various aspects are analyzed including collapse time, shock wave amplitude, and energy radiation directionality. The simulation results indicate that the implosion pulse amplitude increases with the initial size, approximately following a power‐law relationship, for spherical and cylindrical structures, either constrained or unconstrained. The implosion shock wave amplitude is sensitively affected by the internal air pressure of the structure. However, the fitting trend between structural size and pulse amplitude is almost comparable. In terms of energy radiation, different from the isotropic radiation pattern of spherical structures, cylindrical structures exhibit distinct directional energy radiation characteristic and vary with size and constraint conditions, attributed to variations in vorticity and pressure gradients, which modulate fluid velocity distribution. This study explores the implosion dynamics under different structural and constraint conditions, providing insights for analyzing implosion origin based on observations and advancing the utilization of implosion energy.