Analysis of Launch Mechanism for Coaxial Induction Coil Launcher Based on Armature's EMF

Launch mechnism of coaxial induction coil launcher (CICL) is investigated based on the theoretical analysis of the armature's emf and its effect. The distributions of J in the armature for the given conditions of the dynamic operation and of eddy field are compared, which verifies the correctness of theoretical analysis. In addition, the influences of the armature's motion effect on the accelerative performance of CICL are researched by means of the method of finite element analysis. Researches show that the directions of J(e) and J(v) are opposite in the early launch process. J(e) has acceleractive function for the armature in early operation process of CICL, and J(v) has deceleraction function for the armature. Only J(e)>J(v), the armature can be accelerated. When J(e)<J(v) and J(e) changes its direction, the armature will be decelerated. The armature's motion effect has important influences on the acceleractive performance of CICL. The armature speed's enhancement not only results in the increase of E-v and the driving coil's back emf but aslo results in the decrease of the transient time of the armature in the driving coil. These factors are of no avail to CICL working under the high speed conditon.