Research on Accelerative Characteristics of Three Kinds of Coaxial Induction Coil Launchers

Coaxial induction coil launchers (CICLs) can be classified as an outer driving CICL (ODCICL), inner driving CICL (IDCICL), and inner-outer driving CICL (IODCICL) according to the location relationship between the driving coil and armature. The researches on ODCICLs have been made widely and deeply, but the researches on IDCICLs and IODCICLs have not been found in existing literature. This paper discusses the accelerative characteristics of the three kinds of CICL and investigates the distributions of the magnetic and eddy fields in the three kinds of CICL by means of a finite-element analysis method. Under given conditions (C = 1000 μF, U = 5 kV, Z = 5, and m = 237 g), the waves of the driving current and the curves of the accelerative force on the armature and the displacement and speed of the armature for the three kinds of CICL are presented. The research results show the following points: (1) The accelerative characteristic of the IDCICL is the worst among the three kinds of CICL, but it is fit for accelerating the load with a big volume and a high mass; (2) the accelerative characteristic of the ODCICL is the best among the three kinds of CICL, but its load is limited by the driving coil; (3) the IODCICL, particularly the magnetic field reconnection IODCICL, has a better accelerative characteristic than the IDCICL, and the distribution of the eddy current in the armature is relatively more uniform than that in the ODCICL. However, its structure is relatively complex, which leads to design and realize it more difficult than the IDCICL and the ODCICL.