Flame-Spreading Processes in a Small-Caliber Gun

摘要

The interior ballistic cycle of small guns (40 mm and below) has in the past been typically modeled with the use of lumped parameter codes that assume instantaneous ignition of the entire propelling charge followed by uniform combustion throughout the chamber at each instant in time, with the buring rate governed by an instantaneous space-mean pressure. In this study, a two-phase flow approach is employed to model the interior ballistics of a generic 5.56-mm gun, focusing on the ignition and flame-spreading dynamics in the gun chamber, the formation of gas and intergranular stress waves, and the ultimate effect of thes processes on gun performance. Results suggest that the flame-spreading portion of the cycle plays a significant role in the overall phenomenology occurring within such guns, outside the scope of lumped parameter analysis. Approaches for exploiting this improved understanding of small- caliber interior ballistic phenomenology are identified, with respect to improved performance and safety.