Simulation of shock wave propagation of near free surface underwater explosion

摘要

Characteristic of underwater explosion shock wave near a free surface is investigated with numerical simulation. The shock wave propagation is shown clearly and described correctly by changing parameters of water's equation of state, loading water gravity and setting non-reflect boundary, etc. Two matters have been found and analyzed: the shock wave propagation affected by charge-water boundary and water-air surface; special phenomena of shock wave named hump, shock wave cutoff and shock wave oscillation. The appearing range of the special phenomenon is obtained. And a new fitting formula in the range nearby the charge is given. Comparing with the calculated values in deep water explosion, the peak pressure of shock wave is decreased more quickly in near free surface underwater explosion. The results will bring better application in the field of warship design and self-defense.