Relationship between Slivering Point and Gas Generation Rules of 19-Perforation TEGDN Propellants with Different Length/Outside Diameter Ratios and Perforation Diameters

Abstract

ABSTRACTIn order to investigate the relationship between the slivering point and burning progressivity, a set of 19-perforation propellants containing triethylene glycol dinitrate (TEGDN) with different lengths/outside diameter ratios and perforation diameters was prepared and tested in a closed vessel. The mass fraction of burnt propellant was derived from the recorded pressure–time history of 19-perforation TEGDN propellants in the closed vessel according to the gas state equation and the form function of tested propellants. Based on the form function calculation and the mass fraction of burnt propellant, instantaneous burning surface area and the burning rate were obtained. The influence of length/outside diameter ratios and perforation diameters on the progressive combustion performance is studied through the dynamic vivacity method. With an increase in the length/outsider diameter, the slivering point occurs earlier and the slivering process lasts longer. Further, the burning progressivity of surface area can be improved. For propellants with same length/outside diameter ratio, with a decreasing of perforation diameter, the slivering point lags behind and the burning progressivity becomes greater. The slivering point corresponds to the instantaneous burning area, which is related to the form function and total burning process as well. However, the total burning progressivity of propellant is a very comprehensive result of propellant under multiple actions, including the mass fraction of burnt propellant, grain size and burning rate at different pressure regions. The correlation between them can boost a better understanding on the interaction between grain size, slivering burning process and burning progressivity.