Development of the analytic relations for the propellant grain geometrical characteristics required for a maximum pressure plateau feature

Abstract

By using the fundamental interior ballistics relations, developed based on some simplification hypothesis, there was deduced a formula for the geometrical characteristics that allow the occurrence of a constant pressure plateau in a gun when a charge composed by a single type of undeterred propellant grain is used. The equation incorporates various factors as propellant ballistics properties, the gun/projectile/propellant gabaritical data and the targeted maximum pressure value. Nevertheless, the calculus done on a realistic set of data indicates the impossibility to reach a constant pressure plateau when a propellant characterised by a single set of geometrical characteristics over the entire web thickness is use.