Influence of Gun Bore Structure on the Performance of Interior Ballistic Process

Abstract

In order to find out the influence of gun bore structure on the performance of interior ballistic processes, a modified interior ballistic model is established. In the model, the energy conversion of an interior ballistic process is analyzed in detail, and many components of energy are absorbed into an item that is expressed in the form of work output from propellant gas system. With the combination of computational solid mechanics and fluid mechanics, the modified interior ballistic model can be solved without the use of a coefficient of energy losses. The relationship between the shot-base pressure and the mean pressure is derived under the hypothesis of Lagrange. And the projectile is directly pushed by the shot-base pressure and resisted by forces that source from the contact between a projectile and its barrel. In this paper, the classical interior ballistic model is modified firstly. Then the twist angle of the rifling and the forcing cone angle are selected as characteristic parameters of the gun bore structure, and their influences on the performance of interior ballistic processes is studied. In order to characterize the influences, a coefficient of energy losses is directly defined. Based on the simulated results, the coefficient is calculated and the influences are analyzed.