Influence of propellant geometry on erosion in vented vessel tests

The range of barrel weapons can be increased by using more powerful propellants. For the development of new, more powerful propellants, the erosivity on the gun barrel plays a significant role. During the combustion of propellants, high pressure and high temperature occur, which have a significant influence on the erosivity of the gun barrel. The combustion behavior is essentially determined by the chemical composition, the propellants' grain geometry and the combustion boundary condition, particularly the volume of the combustion chamber. The erosivity can be investigated experimentally at an early stage of development by so-called vented vessel test. In previous research on erosive properties, different chemical compositions of propellants have been investigated. In this work, the influence of grain geometry on the erosive properties of JA2 is examined. For this purpose, different grain geometries (solid cylinder, 1-preforated cylinder and 7-perforated cylinder) were shot at different loading densities in the vented vessel and the eroded mass in the nozzle was determined. The experiments were evaluated according to the methods of Kegler & Grune, as well as Hund. It was shown that propellants with progressive burning behavior exhibit lower erosivity than propellant powders with degressive burning behavior.