The interior ballistic performance of propellant charge with ultra-large length-to-diameter

In order to thoroughly verify the stability of interior ballistic of propellant charge with ultra-large length-to-diameter that used in a ship-borne large-caliber weapon, the interior ballistic experimental method was conducted to study the interior ballistic parameters including the initial velocity and chamber pressure of a propellant charge with ultra-large length-to-diameter about 8:1 under different temperature conditions. It was found that the maximum average chamber pressure of propellant charge with ultra-large length-to-diameter was 343.9 MPa, 339.7 MPa, 349.7 MPa under low, room and high temperatures, while that of the average initial velocity was 701.9 m·s-1, 710.9 m·s-1, 723.1 m·s-1, respectively. The muzzle velocity probable error of propellant charge under normal temperature can be controlled within 1.6 m·s-1. Besides, it was confirmed that the obtained pressure-time curves were smooth without any steps under low temperature, normal temperature and high temperature, demonstrating that propellant charge can burn steadily in the barrel, which conforms to the combustion feature of the propellant charge in the barrel during the firing process. Meanwhile, the initial velocity and chamber pressure of was calculated based on the classical internal ballistic calculation method, combined with the measured pressure-time curve, the curve relationship between the movement path of projectile, the muzzle velocity and the chamber pressure were theoretically calculated. It was found that the results of interior ballistic experimental was accord with the result of theoretically calculation. Hence, this present work prospectively to provide basic support and guidance for the development of a new propellant charge used by weapon for shipborne and other high-performance combat platforms.