Optimizing the Form Function of Gun Propellants

Abstract

Progressivity, i.e. gain in burning area, of multi-perforated propellant grains is graphically shown to have a maximum for certain dimension ratios. Form functions, amount of slivers, and optimum dimensions for some basic grain types are presented. The effect of finite manufacturing precision on form function, progressivity, and amount of slivers is estimated approximatively. This study of form functions is strictly geometric, no physical effects of combustion, like flame spread, combustion inside perforations, or erosive burn rate, are taken into account.