Assessing the energy release characteristics during the middle detonation reaction stage of aluminized explosives

Abstract

Afterburning behind the detonation front of an aluminized explosive releases energy on the millisecond timescale, which prolong the release of detonation energy and the energy release at different stages also shows significant differences. However, at present, there are few effective methods for evaluating the energy release characteristics of the middle reaction stage of such explosives, which can have a duration of tens to hundreds of microseconds. The present work demonstrates an approach to assessing the mid-stage of an aluminized explosive detonation based on a water push test employing a high degree of confinement. In this method, the explosive is contained in a steel cylinder having one end closed that is installed at the bottom of a transparent water tank. Upon detonation, the gaseous products expand in one direction while forcing water ahead of them. The resulting underwater shock wave and the interface between the gas phase products and the water are tracked using an ultra-high-speed framing and streak camera. The shock wave velocity in water and the expansion work performed by the gaseous detonation products were calculated to assess the energy release characteristics of aluminized explosives such as CL-20 and RDX in the middle stage of the detonation reaction. During the middle stage of the detonation process of these aluminized explosives, the aluminum reaction reduced the attenuation of shock waves and increased the work performed by gas phase products. A higher aluminum content increased the energy output while the presence of oxidants slowed the energy release rate. This work demonstrates an effective means of evaluating the performance of aluminized explosives.