REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

OPTIMAL PROPELLANT GRAIN GEOMETRY DESIGN FOR LARGE CALIBER PROJECTILES

FUNDA YILDIRIM

Mechanical and Chemical Industry Corporation, Ankara, TURKEY, funda.yildirim@mkek.gov.tr

ERKAN TİRYAKİ

Mechanical and Chemical Industry Corporation, Ankara, TURKEY, erkan.tiryaki@mkek.gov.tr

MEHMET KABAK

Ankara University, Faculty of Engineering, Ankara, TURKEY, mkabak@ankara.edu.tr

Abstract: Propellant charge is rapidly burning composition of low explosive that is burned inside the gun chamber, to propel the projectile. Determining the muzzle velocity of projectile is a critical issue and it directly depends on the gas pressure and force generated inside the chamber. Aim of this study is optimization of web thickness of propellant to get required gas pressure and force, means required muzzle velocity. Since the burning of a propellant occurs only on the exposed surfaces, the smallest dimensions between the exposed surfaces become the critical dimensions, as it determines in general when propellant will be completely consumed. This critical dimension is called web thickness. In this study, optimum web thickness is obtained by investigating effects of grains’ shape and dimensions that one of the major factor of determining burning rate. The effects of some constant web thickness values for different propellant types (ball, cylindrical and, 1, 7, 19, 37 perforated cylindrical propellants) are investigated and the effects of variable web thickness values within each propellant type is investigated. Resulting muzzle velocity and pressure values are determined by using “PRODAS” software. From these muzzle velocity and pressure values, optimum web thickness value is calculated with non-linear regression method by using “MATLAB Optimization Tool”.

Key words: pressure, muzzle velocity, propellant, web.