Numerical Modeling of Heterogeneous High Explosives

Abstract

Abstract : This report contains a numerical algorithm for modeling the detonation and explosion of a heterogeneous mixture of high explosive and small metal particles. The simulation examines a spherical explosive design with a mixture of nitromethane as the high explosive and steel as the metal particles. The algorithm provides a computational model of the detonation and explosion by producing position, velocity, and temperature profiles for the metal particles over time. For the gas phase, the algorithm produces position, velocity, temperature, density, and pressure profiles over time. This is accomplished by taking into account the initial position and velocity profiles for the metal particles, a corresponding particle drag law, appropriate explosive energy and detonation pressure inputs, and a blast wave solution that governs the thermodynamic state of the gas phase. The behavior of the solid particles and gas phase throughout the explosion is simulated by a coupled, two-phase algorithm. The results of the model are compared against experimental data and critiqued on a theoretical level as well. Recommendations and plans for improvements to the algorithm are discussed. This model is intended to provide a sound representation of the detonation as well as insight into the behavior of a heterogeneous explosive.