Numerical Analysis of the In-Bore Magnetic Shielding of the Series-Enhanced Electromagnetic Railgun

Abstract

Based on the theory of moving electromagnetic (EM) systems, a 3-D numerical simulation model of the transient EM field of the series-enhanced EM railgun is established by using the finite element (FE)/boundary element (BE) coupling method. The sliding electrical contact between the armature and rails is also considered in this model. The distribution of in-bore magnetic field of this kind of railgun is compared with the one of the monorail railgun. Based on this model, the evolutions of the current of the in-bore shield and the EM field in this shield’s cavity are simulated in its launching process. The effects of the shield’s materials and motion on the induced current and magnetic field of the shield are analyzed. The results reveal that because of the addition of the enhanced rails, the distributions of the current and the magnetic field in the rails and armature for the series-enhanced EM railgun are different from the ones for the monorail railgun, and the distribution of the in-bore magnetic field for the former is more complex than the one for the latter. The structure of induced current in the copper shield is basically similar to the one in the industrial pure iron, but there are some differences in their evolutions between the two kinds of material shields, which lead to the differences in the distributions of the magnetic field. The shield’s motion influences the distribution of the magnetic field in the shield’s cavity, which is a complex process.