Multifield Coupled Analysis of a Launch Coil in Active EM Armor

An active electromagnetic (EM) armor is a new kind of active defense system, which consists of advanced detector, control system, high pulsed-power supply, and EM launcher (EML). Electric energy provided by the high pulsed-power supply can be transformed into kinetic energy of the interception projectile with EML. Hit by interception projectiles, the invading object could be totally destroyed or deviate from its trajectory. In the EML the launch coil is a key component and it could be destroyed when the peak current load exceeds a certain value. In this paper, the structure and working principle of the EML are introduced. By means of ANSYS software, a 3-D finite element model of the EML is established, and multifield coupled analysis (EM-thermal-structural analysis) of the launch coil is accomplished during the loading process. The distribution of temperature, deformation, and stress of the launch coil versus time are achieved. Influence of the current loads on the temperature and strength of the coil are also analyzed. The results indicate that the maximal temperature, deformation, and stress appear at the center of the launch coil and this part is easy to be destroyed. It is well-matched with the experimental results.