The changing law of underwater explosion shock wave parameters with hydrostatic pressure

The effects of hydrostatic pressure on shock wave parameters were analyzed by using a combination of experiments and numerical simulations in this paper. The functional relationship between the overpressure peak and hydrostatic pressure was established, and the functional expression between the slope of the linear change and the specific distance was obtained. Underwater explosion experimental data were obtained for 0.3 g Pentaerythritol Tetranitrate (PETN) under four working conditions with initial pressures of 0.1, 0.25, 0.5, and 1 MPa. The underwater explosion of 0.3 g PETN was simulated under 11 working conditions with initial pressures ranging from 0.1 to 30 MPa using ANSYS software. In the simulation, the effects of water depth on the density of the water medium and the speed of sound were considered. The accuracy of the simulation was verified in comparison with the experimental data. According to the simulation results, the overpressure peak of the shock wave (the difference between the positive shock wave pressure and hydrostatic pressure), the decay characteristic time θ, the propagation speed, the impulse, and the specific shock energy with the change rule of hydrostatic pressure can be obtained. The results show that the decay characteristic time θ, the impulse, and the specific shock energy decreased with increasing hydrostatic pressure, and the decay amount increased with increasing distance. The overpressure peak of the shock wave and propagation speed linearly change with increasing hydrostatic pressure, and as the distance increases, the increase in the overpressure peak value decreases.