Thermal Analysis on Electromagnetic Launcher Under Transient Conditions

Since a tactical electromagnetic railgun system is required to fire several times a minute, the thermal load on the rails leads to a higher temperature, which will even result in launch failures and reduce the life span of the launcher. In this paper, the rail temperature was measured during the launch experiment. Furthermore, based on a 3-D transient model with moving armature, mechanically, thermally coupled electromagnetic field analysis using finite-element method is presented. The Joule heating is one of the main heat sources in the rails. Contact resistance and friction force that cause heat between the armature and the rail are also included in the model. The simulation results show that the peak temperature in the rail occurs at the inner surface. Overall, along the direction of armature motion, the temperature of the rail near the breech end is higher than at the muzzle end, and the maximum temperature on the rail appears near the initial position of the armature. The contact resistance contributes much more than friction to the temperature rise in rails.