A bond graph model of an electromagnetic launcher

Abstract

An electromagnetic launcher (EML), also known as a railgun, is a complex, dynamically coupled system with interacting electric, magnetic, mechanical, and thermal subsystems. Presented is a bond graph model of the EML forward propulsion, including electrical systems (power supply, rails, armature, skin effect in rails, and electrical contacts between armature and rails), magnetic effects (Lorentz forces and response of magnetic containment system for magnetic flux), mechanical systems (motions of armature and launch package) and interactions between armature motion and magnetic field (i.e., velocity skin effect). The bond graph model will be constructed, from which governing state equations will be extracted, and simulation results presented.