Simulations on Arc Surfaced C-Shaped Armatures for Round-Like Bore Railguns

Previous solid armature design studies have emphasized the effect of geometry change on armature performance. In order to acquire more uniform contact pressure and current density distributions at the armature-rail interface, the novel modified C-shaped armatures for round-like bore railguns are proposed and analyzed. By removing and adding two pieces of circular arch from the conventional C-shaped armature trailing arms, we construct two types of arc surfaced C-shaped armature (ASCA) for corresponding round-like bore railguns. They are called concave ASCA and convex ASCA. In this paper, both concave ASCA and convex ASCA are simulated with finite element method. The detailed description and construction of the model are presented. 3-D calculations of contact area, contact pressure, and current density distributions are performed and compared. Specially, current density simulations are modeled according to the results of elastic contact calculations. In addition, split-leg ASCAs are also simulated and discussed. The simulation results show that the performances of one split-leg concave ASCA are the best. Further electromagnetic launch experiments of concave ASCAs are in good agreement with the simulation results.