Multiphysics Simulation of Synchronous Induction Coilgun Based on Implicit Function and Level Set Method

The launch of synchronous induction coilgun (SICG) is always accompanied by strong thermal and structural effects, which will cause serious damage to the structure of the armature, and multiphysics computation is an effective means to avoid this problem. Compared with the conventional circuit-based model, the finite-element analysis (FEA) is more suitable for the multiphysics computation of SICG, but it is also more time-consuming. In this article, the implicit function and level set (IFLS) method is introduced to rapidly simulate the multiphysics problem of SIGC based on FEA. The armature is modeled implicitly in the material domain and the position of it is updated through the implicit function, avoiding the moving mesh and remesh problems in the arbitrary Lagrangian-Eulerian (ALE) method, which is generally used to dealing with the dynamic mesh problem. Besides, the volume loss density and the Lorentz force per unit in the moving band are transformed back to the initial position to complete the coupling of the thermal and structural field and maintain the accuracy and continuousness of the simulation. A single-stage SICG model is established with the ALE and IFLS methods, and the results show that the computation time of the IFLS method is nearly halved. Finally, the IFLS method is applied to the simulation of multistage SICG, and the computational efficiency is greatly improved.