Simulation of convective combustion reactions in PBX based on DEM–CPM

Convective combustion is a characteristic process in the violent evolution of polymer-bonded explosives (PBX), which increases the reaction and causes rapid pressurization, high reaction violent explosion, or deflagration to detonation. Thus, simulations of convective combustion reactions are necessary to predict the risks associated with violence properly. There is rapid pressurization in the crack and flame penetration that are the main characteristics of convective combustion. Traditional numerical simulation methods are not applicable to simulate PBX convective combustion reactions. Therefore, in this paper, a discrete element method coupled with the corpuscular method was proposed, combined with the Ward-Son-Brewster (WSB) burn model. By using this method, the dynamic mechanical responses of PBX, the reaction products, and the combustion of PBX are modeled by the discrete element, gas particle, and WSB combustion mode, respectively. This coupled method has been validated by the simulation of the slot-pressurization experiment. Furthermore, the reaction evolution after ignition in PBX was simulated, as well as the process of flame penetration into charge. The analysis of flame penetration into the charge contributes to a deeper understanding of the violent event of PBX.