Control of thermal limitations in railguns

In this paper, the possibility of controlling the current concentration region on the perimeter of the rail-armature interface in electromagnetic accelerators of conducting solids is analyzed by numerical simulation of unsteady distributions of magnetic fields, currents, and temperatures in a three-dimensional formulation. The objective of the work is to reduce the rate of Joule heating of armatures during acceleration and to increase the ultimate (under heating conditions) kinematic characteristics of accelerators by choosing the optimal shape and structure of armatures and rails and the electrothermal properties of the armature and rail materials. It is shown that, by controlling the structure and electrothermal properties of the electrodes and accelerated body, it is possible to significantly reduce the thermal limitations during high-velocity electromagnetic acceleration of solids and increase the ultimate kinematic characteristics of railguns in subcritical modes of their operation.