Influence of afterburn reaction on the underwater explosion of aluminized explosives

There is confinement of a bubble that provides a long time for the afterburn reaction of aluminum (Al) additives when aluminized explosives explode in water, and the information of the reaction is reflected by the dynamic behaviors of a bubble. In this study, the energy partition of RDX-based aluminized explosives with different Al content was obtained in an underwater explosion experiment, and the influence of an afterburn reaction on the bubble accelerating expansion, decelerating expansion, and contraction was revealed. It found that the pressure in these stages was changed with different Al content, leading to the variation in the reaction process of Al that releases the afterburn energy. Based on the analysis of the afterburn reaction of full stages, the afterburn reaction process in accelerating expansion was in agreement with that in metal acceleration of a cylinder test and the afterburn reaction mechanism in high pressure was validated; the afterburn reaction characteristics in decelerating expansion and contraction stage were obtained and the reaction mechanism of low pressure was developed. This research is significant to optimize the contribution of the afterburn reaction to explosion performance of aluminized explosives.