Characteristics of Temporal and Spatial Distribution of Railgun Contact Heat

A good understanding of the temporal and spatial distribution characteristics of the railgun contact heat is an important basis upon which to suppress armature melting, design the rails cooling system, and control the thermal management.In this work, based on the calculation models of the contact pressure and contact resistance of the armature and rail, the calculation model of the railgun contact heat temporal and spatial distribution was built, the temporal and spatial distribution of the contact heat was simulated, and the distributional characteristics were analyzed.Aiming at the problem of the relative concentration of the contact heat in the initial stage of the armature movement, the effect of the armature pre-acceleration on the temporal and spatial distribution of the contact heat was examined.The simulation and analytical results show that the contact heat originates mainly from the current's Joule heat, the curves of whose power and driving current have great similarity; most of the contact heat is conducted to the rails in the initial stage of the armature movement, which is the primary cause for the rail erosion; both the contact heat conducted to the unit length rail in the initial stage and that accumulated in the armature during the launching process decrease with the increase of the armature initial velocity.