Effect of rail dimension on current distribution and inductance gradient

Railgun is one of the most important electromagnetic launchers that can accelerate a projectile to hypervelocity. Current distribution in railgun structure is the effective factor that determines its efficiency. Current density is affected by rails and armature geometry and dimensions. This paper investigates how the rails dimensions and spaces affect the current density distribution, magnetic flux density and inductance gradient (L'). L' plays an important role in the performance of an electromagnetic launcher (EML), and it determines directly the force that accelerate projectile. Finally L' for various dimensions are tabulated and compared with values obtained from other methods. A finite element method is discussed to simulate two dimensional railgun in this study.