DETERMINATION OF GUN PROPELLANT BALLISTIC PARAMETERS WITH A FOCUS ON FLAME SPREAD AND GRAIN DIMENSIONAL VARIATION

Abstract

In interior ballistic simulations, the burn time can be affected by the burn rate, propellant dimensions and flame spread. Standard IB models assume that grains are symmetric with no variation in dimensions, with instantaneous homogeneous ignition. This paper evaluates the contribution of grain dimensional variation (specifically the web), asymmetry and flame spread in a single base propellant with a single perforated grain geometry. It is shown that flame spread has the dominant effect on burn time, followed by web dimensional variation and lastly asymmetry. The implementation of these effects also leads to a simulated result that is more representative of the experimental curve in the closed vessel especially in the burnout phase.