Interior Ballistic Two-Phase Flow Model of Guided-Projectile Gun System Utilizing Stick Propellant Charge

Launching a guided projectile from conventional artillery is a very sensitive process for both the propelling charge and the gun system. Hence, a specific mathematical model based on two- phase fluid dynamics of solid single-perforated high density stick propellant and its products of combustion inside the gun tube during interior ballistics cycle is developed. The model includes the governing equations of mass, momentum and energy for both phases as well as the constitutive laws. The simulations are applied to conventional large caliber naval gun firing a guided projectile. The results are compared with the experimental data of granular propellant grains for validation. Different stick propellant grain design parameters are investigated. The grain size significantly affected the maximum chamber pressure and then the guided projectile muzzle velocity. An appropriate stick grain size condition exists, where the minimum pressure wave generation can obtained. Based on the simulation results, an apparent guideline for the proper design of stick propellant charge for launching guided projectiles is presented.