Three-dimensional magneto-thermo-mechanical coupling analysis with the influence of velocity skin effect

Abstract

In this paper, the three-dimensional magnetic diffusion governing equations of an electromagnetic railgun are derived based on Maxwell’s equations and coupled with the energy equations. The finite element method is used to calculate the current density, temperature, and electromagnetic force distribution for armature velocities of 0, 200, 600, and 1200 m/s. The results show that there is a current concentration phenomenon on the rail’s inner surface and the trailing edge of the contact interface; the temperature rise of the rail along the moving direction of the armature tends to decrease, and ablation occurs at the corner of the moving armature’s trailing edge. An increase in the velocity of armature movement results in an increase in the electromagnetic forces on the armature and contact surface. This model can effectively represent the variation of each physical quantity with velocity and provide direction for the optimal design of the rail and armature.