Influence of the Вimension of the Mathematical Model of Internal Ballistics and Back Pressure on the Calculated Parameters of the Shot

Abstract

The paper presents the main problem of internal ballistics in averaged parameters. A distinctive feature of the given problem post-new from existing statements is the consideration of the distribution of pressure and gas velocity behind the shot for a channel of variable cross-section within the framework of the thermodynamic approach assumptions. When integrating equations in time, a two-step Runge-Kutta SEMA with the second-order of accuracy is used. The paper also presents the formulation of the RSA in the framework of a one-dimensional gas-dynamic approach. The control volume method is used for the numerical solution of a system of gas-dynamic equations. Gas parameters at the boundaries of the control volumes are determined using a self-similar solution to the problem of the decay of an arbitrary gap. A comparison of solutions obtained in the framework of thermodynamic and gas-dynamic approaches for different charging parameters in the Lagrange problem's framework is made. The effect of camera widening on the distribution of intra-ballistic parameters of the shot and counter-pressure on the dynamics of the projectile movement is studied. The backpressure as the pressure of the detached shock wave derived from the analytical solution of the problem of supersonic movement of the piston in the pipe with constant velocity is compared with the pressure acting on the shell, determined from the solution of unsteady one-dimensional gas dynamics equations.