Modeling for the Calculation of Interior Ballistic Velocity of Electromagnetic Rail Launch Projectile

Interior ballistics is of great importance to the study of gun barrels and projectiles. One of its important characteristics is velocity, which determines the firing capability of projectiles. Aiming at the interior ballistic velocity (IBV) of projectiles launched from electromagnetic (EM) rail, this paper has analyzed the differences in the mechanism between the EM rail gun and the traditional cannon. Based on some assumptions, the calculation formula of projectile EM force was gained with the time-frequency analysis method. Then, it built a simulation calculation model of IBV of the projectile. In addition, the use of the positioned data of the magnetic probe (B-dot probe), to obtain the displacement fitting matrix, leads to the establishment of an experimental fitting model of IBV of the projectile. With the plane EM rail launcher in our laboratory as an example, the above-mentioned two models are applied to analyzing the accelerated motion of the projectile in the chamber. The experimental fitting results are compared with the measured data and simulation results of the B-dot probe, which are basically consistent. Thus, it shows that the IBV's simulation model and the experimental fitting model have high reliability.