Determination of the parameters of induction-type electromagnetic launchers

This paper presents a lumped parameter equivalent circuit model for cylindrical induction-type electromagnetic coil-launchers based on an electrornagnetic-field transmission-line approach. Basic closed form design formulas are derived from the model. System parameters and performance indices are obtained from the circuit model and related to the dimensions of the launcher. Currents in the linear array of barrel and projectile (sleeve) conductors are represented by two voltage controlled current sources. A modified planar model is also considered. Limitations of each level of approximation are presented. Formulas for determining the electrical time constants of the launcher are included. Data from static experiments with a small model are compared with calculated results.