Shock physics of non-ideal detonations for energetic explosives with aluminum particles.

摘要

The non-ideal behavior of condensed explosives with metal particle additives 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 pressure are measured, although under many circumstances an increase in performance of metallized explosives is measured. Little to date has been measured regarding the complex kinetics mechanism that is present in these flows under extreme conditions. Typical pressures and temperatures of the detonation products of high explosives are in excess of 30 GPa and 5000 K, respectively. To investigate these phenomena, an unsteady, one-dimensional model is presented that simulates the build-up toward steady detonation of an organic explosive, HMX (cyclotetramethylene tetranitramine), containing dispersed aluminum particles. Heat liberated by secondary oxidation reactions of Al (aluminum) with the products of the initial decomposition of the explosive is modeled, and parametric studies are presented in which the ignition delay time and the rate of the aluminum reactions are varied. Endothermic processes such as the heat transfer to the aluminum particles and the formation of the product aluminum oxide particles are also simulated.;Results indicate that the induction delay for the aluminum particles, combined with endothermic processes, alter the structure of the reaction zone, and produce a secondary shock wave which never reaches the detonation wave front. Additionally, under certain combinations of heat transfer rate and chemical release rate, the measured behavior can be reproduced, and the model results indicate that these phenomena have a significant effect on the detonation parameters and should be included in future models.