Constant-volume combustion performance of mixed charge of foamed propellant with nitramine propellant

Foamed propellants based on polymer bonded nitramine explosives show high burning rates due to their porous structure and showed great potential for combustible cartridge case. Thus, the in-depth study of the co-combustion behavior of the foamed propellant and matching propellant is necessary. In this paper, closed bomb tests were used to study the co-combustion performance of nitramine propellant (RGD7) and surface coated nitramine propellant (SC-RGD7) mixed with foamed propellant. The influence of foamed propellant’s proportion in mixed charges on the combustion behavior was studied and analysed. It was found that the maximum dynamic vivacity and the value of B at maximum dynamic vivacity of mixed charge increased with the increase of added foamed propellant, resulting in better combustion progressivity. Meanwhile, the ignition delay of foamed propellant influenced the first stage of combustion, and the penetration combustion of foamed propellant influence the middle stage.