SINGULARITIES OF BURNING RATE DETERMINATION OF FINE-GRAINED PROPELLANTS

摘要

Internal ballistic analysis usually assumes that propellant grains are all of the same size and configuration, and they are ignited uniformly with all surface areas of the grains exposed. According to these assumptions the burning rate of propellant is determined from closed vessel tests. The burning rate law coefficients may be calculated from differentiation or integration of experimental pressure-time curve obtained from closed vessel testing. Different fine-grained propellants were fired in closed vessel tests to determine their burning rate behaviour. In order to determine burning rate law coefficients the variations in mass of igniter material (black powder) and variations in initial temperature of propellant at the same value of loading density were used. The rate of pressure change and dynamic vivacity calculations obtained from closed vessel experiments let us understand the physics of the interaction of involved energy from igniter material with gun propellant and report the influence of the phenomena on values of burning rate coefficients.