Investigation of the shock wave load characteristics in deep-water explosions based on high-order compressible multiphase fluids

We present a high-order compressible multiphase fluid solver to investigate the shock wave dynamic characteristics in deep-water explosions with energetic material detonation. The spatial terms of the system equations are discretized using fifth-order weighted essentially non-oscillatory reconstruction in characteristic space and Lax–Friedrich's splitting, while the temporal terms are discretized using a third-order total variation diminishing (TVD) Runge–Kutta scheme. The multiphase interface is captured by the level-set method combining modified ghost fluid method , and a programmed burn model is proposed to describe the phase transition from unreacted material to gaseous products and the release of detonation chemical energy. The solver is validated through comparison with other literature results and experimental results. The early shock wave characteristics of trinitrotoluene (TNT) and RS211 charges at different water depths are investigated, and numerical results indicate that the peak value of relative pressure and wave speed increase approximately linearly with increasing water depth. The near-field explosions of cylindrical TNT charges under different water depth conditions are examined using two different initiation patterns, revealing that the shape of the explosive charge significantly influences near-field underwater explosions.