Burning Mechanism of Foamed Oblate Spherical Gun Propellants

Abstract

The micro-porous oblate spherical gun propellants prepared by supercritical carbon dioxide (SC-CO2) foaming technique exhibit high burning rate due to their porous structures. The morphologies of foamed oblate spherical propellants are characterized by scanning electron microscope (SEM), the SEM photos show that there exist massive separated micro pores in the foamed propellants. To investigate the combustion process ， both the quenched combustion experiments and closed vessel experiments were carried out in this work. The results of closed vessel experiments show that burning time of foamed propellants is less than that of unfoamed samples, which indicates that the burning rate of foamed propellants is higher than that of the unfoamed samples. The results of quenched combustion experiment show that the burning surface area of foamed oblate spherical propellants is very large. Besides, the separated pores get connected during the burning process, and this increases the burning thickness. It is believed that the large burning surface area and increased burning thickness lead to the high burning rate of the foamed propellants.