Thermal and electromagnetic analysis of an electromagnetic launcher

An advanced high-power electromagnetic launcher (EML) improves performance by as much as 30% over conventional launchers. Electrical energy is the main driving source for the electromagnetic launcher. In the new EML, thermal energy, generated by the extraordinarily high current that goes through the rail and the armature, changes the electrical, thermal, and mechanical specifications of the structure. This paper reports on a study of the thermal and magnetic induction distribution in the rail and the armature at different locations. In our formulation of governing nonlinear differential equations, because of the electrical conductivity and ohmic heating of the rail and the armature, Maxwell equations are coupled with energy equations. The friction force that causes heat between the armature and the rail is considered in the equations, as is the melting latent heat effect. To solve the nonlinear governing differential equations, we utilize an unstructured, moving-mesh-generation, control-volume-based finite-difference code for the rail and the armature. In this method of solution, unlike most others, the rail stays stationary and the armature moves in the forward direction. Results obtained for the rail and the armature show that the maximum temperature occurs at the trailing edge of the armature. In this region, the temperature reaches about 600 K. However, the temperature of 1 m of rail stays around 360 K.