Influence of AP solid-phase decomposition on temperature profile and sensitivity

Abstract

Previous models of AP were successful in describing the burning rate at different pressure and approximate species concentration profiles, but were less consistent in their calculated temperature profile and temperature sensitivity. The current work has addressed this problem by including solid-phase decomposition, a phenomenon explored recently by Behren in a experiment study. However, while Behren's data only showed the existence of solidphase decomposition from 13% to 25% depending on the size of AP particles and its produced species after decomposition, he did not give the concentration data of these species. In this modeling, we assumed that solid-phase decomposition should nearly go to completion once it starts because the decomposition of solid AP into gas products takes place at very high pressure. In addition, we found the assumption of 30% solid-phase decomposition seems to be more reasonable for releasing sufficient heat to match the gas-phase temperature profile. The calculations show the extreme importance of exothermic heat release near the burning surface. Increasing the exothermic heat release in the solid or in the condensed-phase causes a corresponding increase in temperature sensitivity and decrease in surface temperature gradient.