Investigation of influence of propellant charge temperature on gun firing phenomenon

The temperature of propellant charge, like the level of operating wear of barrel inner surface, influences on pressure impulse of propellant gases inside the barrel during firing process. Value of pressure impulse decides on muzzle velocity of projectile and creates input data to determine projectile trajectory and its terminal ballistics parameters. Existing shooting tables of different weapon systems, enabling precise firing, are based on experimental (very expensive and time-consuming) investigations leading in different ambient temperatures (conditions of operating). Contemporary computer technology makes possible automatic fire control system creation based on solution of closed equation system describing the motion of projectile inside and out of the barrel, taking into consideration influence of different disturbances (including propellant charge temperature deviation). The results of a single-base propellant research with different initial temperature of charges are presented in this paper. Basic ballistic properties, such as the force, covolume and burning rate factor were calculated on the basis of measurements of pressure of propellant gases versus time in the closed vessel. Results of experimental investigations and calculations show influence of initial temperature of charges especially on burning rate.