Numerical Modeling of Underwater Explosion by One-Dimensional ANSYS-AUTODYN

Abstract

This article presents numerical simulation of underwater explosions using a one-dimensional “wedge” model of ANSYS-AUTODYN explicit software for nonlinear dynamics, provided by ANSYS Century Dynamics, Inc. (Canonsburg, PA, USA). Through numerical analysis of a typical underwater TNT explosion problems, the effects of the quadratic and linear viscosity on the key phenomenon of this complicated energetic physical process are conducted. The results show that appropriate values exist for these two viscosities to model the process in given mesh sizes. Based on these preliminary simulations, values of quadratic and linear viscosity, 1 and 0.034, 1 and 0.068 are determined for the ranges of scaled distance from 3 to 10 and 1.5 to 3, respectively. Effects of charge depth, charge mass, and mesh density on the shock wave and bubble pulse parameters are performed for four different explosives, 2,4,5-trinitrotoluene (TNT), H-6, pentolite, and pentaerythritol tetranitrate (PETN). All of the results are compared with empirical equations and show that the ANSYS-AUTODYN software can be used to model and capture the major features of underwater explosion phenomena at acceptable accuracy and timesaving.