Shock physics for nonideal detonations of metallized energetic explosives

The nonideal behavior of condensed explosives with metal particle loading has been studied by many researchers. These previous studies have shown that the explosives behavior is different than that predicted by equilibrium codes (generally lower detonation velocities and pressures are observed or measured), although under many circumstances an increase in performance of metallized explosives is observed. To investigate these phenomena, an unsteady, one-dimensional model is presented that simulates the buildup toward steady detonation of an organic explosive (HMX) containing dispersed aluminum (Al) particles. Heat liberated by secondary oxidation reactions of Al with the products of the initial decomposition of the explosive is modeled, and parametric studies are presented in which the delay time and the rate of the Al reactions are varied. Endothermic processes are also considered. Results indicate that induction delay for the Al particles, combined with endothermic processes, alter the structure of the reaction zones and produce a secondary shock wave that never reaches the detonation wave front. The results of the model are shown to be in agreement with the observed nonideal behaviors of metallized explosives. Future work with the model will include the interaction of the predicted reaction zone structure with a compressible media.