Mechanisms of jet formation and energy release in aluminized explosives: A DEM-FDM study

Understanding the coupled jet dynamics and afterburning reaction of aluminum particles in aluminized explosives remains a challenge due to the ultra-fast interaction, surpassing the resolution capabilities of current experimental equipment. In this study, we employ a coupled Discrete Element Method-Finite Difference Method (DEM-FDM) framework to investigate the jet formation and energy release mechanisms in a prototypical TNT/aluminum system. The simulations explore how varying the mass ratio, particle radius, and packing density influence particle jetting behavior and spatial dispersion. A three-stage jet formation mechanism is identified, characterized by uniform, gradient, and non-monotonic velocity distributions. We demonstrate that the mass ratio dominates jet morphology, while particle radius and packing density exert secondary effects. The afterburning process, captured by finite-rate combustion modeling, reveals a non-monotonic dependence of energy release on both particle dispersion speed and reaction rate. An optimal dispersion speed and reaction rate are identified for maximizing impulse. These findings offer mechanistic insights and design guidelines for performance-optimized aluminized explosive formulations.