Analysis of the performance of a multi-stage pulsed linear induction launcher

In this paper the performance of a multistage pulsed linear induction launcher (PLIL) is analyzed. Attention is focused on the phenomena occurring during the transition between two adjacent stages and on the effects of the coaxial deviation on the motion of the sleeve. The possibility of contacts between the sleeve and the flyway tube and their dynamics is investigated. The analysis has been performed by means of an integral formulation of Maxwell equations that results in an equivalent time varying network. Mechanical coupling has been taken into account assuming a rigid sleeve with three degrees of freedom; the first two are related to the motion of the mass center and the third one is related to rotation around it. Thermal coupling has been considered assuming that the ohmic losses are dissipated adiabatically in the stator windings and in the sleeve. The model has been tested by comparison with results obtained by other researchers in the analysis of a single stage pulsed induction launcher. The analysis of a capacitor-driven five stage launcher has been performed. As the speed of the barrel increases the armature capture effect becomes more evident; the number of contacts with the flyway tube increases and the impacts happen at higher velocity.