Influence of Contacting Schemes on Electromagnetic Force and Current Density Distribution in Armature

The current density and electromagnetic force distribution of the armature directly affect the performance of electromagnetic railgun. In this paper, the electromagnetic thrust, electromagnetic pressure, and current density of the C-shaped armature and H-shaped armature are calculated, respectively, by the finite-element method under different Armature-rail contact modes (different contact areas and positions), and the calculation results under different contact modes are compared. The calculation results show that the maximum current density of the armature head is independent of the contact mode, and the position of the maximum current density of the armature tail moves with the advance of the contact position. The separation of the rear part of the armature tail and rail will result in a sharp decrease in electromagnetic pressure, so the armature tail and rail need to maintain contact to ensure a stable current transfer. At the same time, only the head and the rear part of the armature tail are in contact with the rail, the electrical performance of the armature in complete contact with the rail can be achieved. Therefore, the armature adopts the structural design scheme of interference at both ends, which is more conducive to electromagnetic emission and greatly reduces the difficulty of the armature structural design.