Comparison between conventional railgun and two-turn railgun by 3D- FEM

Abstract

L′ plays an important role in the performance of an electromagnetic launcher (EML). Several approaches for increasing L′ have been suggested. one of these is the stacked railgun, also known as N-turn railgun. Since current density is the decisive factor to transition velocity, this study focuses on the current distribution in armature. The inductance gradient of railgun and magnetic field distribution are also investigated. The L′ of conventional railguns is typically in the range of 0.4 to 0.7 µH/m, depending on detailed rail geometry. thus a two-turn railgun should be expected to have an L′ approaching higher than simple railgun. in this study we will simulate two kinds of railgun including simple railgun and Two-Turn railgun, with finite element method(FEM) and we will compare them. In order to simplify simulations and comparing, rails and armatures of railguns are same. The simple railgun is selected as the benchmark, and the Two-Turn railgun was compared with it. In Two-Turn railgun simulation, the same current source as in simple railgun was connected to rails. Based on simulation results, conclusions are drawn that Two-Turn railgun has the higher inductance gradient and the current density at armatures shoulder is larger. Projectiles of Two-Turn railgun will face the greater magnetic flux density. A finite-element method is discussed to simulate two three-dimensional railguns in this study.