On a Certain Method of Determining the Burning Rate of Gun Propellant

The relation between the burning rate, r, of a solid propellant and the pressure, p, of gases surrounding the burning propellant surface is the basic component of the gas inflow equation. The applicability of a linear form of the burning rate law is limited only to those propellants for which the same pressure impulses, Ip, were obtained during closed vessel tests at different loading densities. To determine the values of the power form of the burning rate law it is necessary to know the values of the energetic and ballistic characteristics of the propellant. In this paper, a method is presented for determining the relation r(p) for which the only input data are the pressure, p(t), of the propellant gases recorded during closed vessel tests (only for a single specific loading density) and information on the shape and geometric dimensions of the propellant grains. An analysis of the possibility of applying the proposed method, through examples of single-base, double-base and multi-base propellants with neutral and progressive characteristics of burning surface changes, was carried out for the purposes of the present study. The qualitative and quantitative results of burning rate analyses prove the validity of the assumptions made.