Influence of long metal wires on combustion of double-base propellants

Abstract

There have already been quite a number of experimental studies and reports, such as Refs. [1] and [2], concerning the influence of long and short metal wires embedded in composite propellant grains by casting on propellant combustibility. However, there have been few reports on the influence of long metal wires embedded in homogeneous double-base and modified double-base propellant grains by continuous extruding on propellant combustibility. Studying the combustion of the grains of propellants with single or multiple long wires embedded by extrusion, we observed that either double-base propellants or modified doublebase propellants, especially with higher energy and higher density, are just as good as some composite propellants with resepet to ballistic performance. This paper discusses the influences of long metal wires embedded in homogeneous double-base and modified double-base propellant grains on their combustibility. The experimental data in this paper are taken from tests of five kinds of propellants given in Table 1. The burning rates of propellant strands, with a single long metal wire embedded by extrusion, are determined with a burner filled with nitrogen. The outer diameter of the propellant strands tested is 6 rnm, and the lateral surfaces of the strands are inhibited so that the burning can only take place at the ends of the strands. In Table 2, we list the burning rate, the ratio of burning rates, and pressure exponent of propellant B, with various embedded wires of diameter 0.18