Analysis of performance of a coil launcher based on improved CFM and non-overlapping mortar FEM

Performance analysis of coil launcher is very important for experimental research and electromagnetic optimization design. In order to check the effect of the improvement and analyze electromagnetic transient in coil launcher, the field coupling circuit simulation method is introduced in this paper. First the current of exciting coils was calculated by circuit model based on improved current filament method (CFM), and then the exciting current was loaded in 2D axisymmetric field model. The field model was built based on non-overlapping mortar finite element method (NO-MFEM). NO-MFEM divided the whole domain into two sub-domains, one contains the movable part(armature) and the other contains the source current(coils). The two sub-domains are discretized independently and the two set of meshes are non-conforming on the interface. When the movable part changes location, it only needs to change the node coordinates in movable sub-domains and information of mortar nodes and elements. In this paper performance analysis of three-stage coaxial induction coil launcher is carried out based on the field-circuit method. The correspondence of the results proves the validity of the field-circuit method.