Influence of Rupture Size on Dispersion Characteristics of Propellant Particles During Ignition and Flame Spreading Processes for Modular Charges

Abstract

During ignition and flame spreading processes, the difference in initial rupture size for the end cover of cartridge may affect the final accumulation form of propellant particles. A 3D unsteady state gas -solid two-phase flow model was established based on the gas phase-grain phase coupling method to simulate the final distribution of propellant particles in the chamber under different initial rupture sizes for end cover. The simulation results showed that at the fan-shaped initial perforation area for end cover of modular cartridge, under the 6 simulated working conditions of central angles 0, 30, 60, 90, 120 and 150 degrees, the propellant particles in the chamber presented a combined form of gentle slope accumulation, horizontal accumulation, and steep slope accumulation from the primer side to the pressure control diaphragm side. When the central angle corresponding to the fan-shaped initial perforation area increased from 0 ° to 150 °, the axial length for gentle slope accumulation and horizontal accumulation increased from 269 mm to 331 mm, and for the part of horizontal accumulation, the average thickness of propellant particles increased from 18.1 mm to 23.5 mm, and the proportion of steep slope accumulation of propellant particles decreased from 70.3% to 63.8%. The larger the initial rupture size for the end cover, the longer the axial length of gentle slope and horizontal accumulation, the thicker the average grain thickness for the part of horizontal accumulation, and the lower the proportion of steep slope accumulation of propellant particles.