Study of a Multisection Synchronous Induction Coil Launcher

Synchronous induction coil launcher (SICL) has advantages of friction-free and simple control. It could he widely used in low-speed ejector and high-speed launch. While multistage SICL is hard to design due to complicated inductive coupling. Armature is often subjected to wavelike electromagnetic force (EMF), which is harmful for the sensitive load. Driving coils are difficult to construct for a large power supply. This paper proposed a multisection SICL to smooth the pull EMF, increase the thrust, and reduce the pressure of each coil. A typical two-section SICL is designed and constructed. Motion characteristics and electromagnetic properties of the launcher are analysed based on finite-element software. The results of simulation and test are in agreement. The single-section and two-section SICL are compared to verify the feasibility of EMF enhancement. Finally, the effect of ignition time on the acceleration smoothness of the launcher is studied.