Characteristics of the Current Distribution in Rails and Armature with Different Section Shape Rails

The rail guns can be classified into three types by the interior surface shape of rails, which are the type of plane-rail, convex-rail, and concave-rail. In this paper, the characteristics of current distribution in rails and armature is analyzed and compared for those three types, during the rising, dropping and the flat part of the exciting current source. The current distribution is simulated by the finite element software ANSYS. The convex-rail type gun is of the weakest opposite direction current phenomenon, and its current distribution on the rail section is the most even. The evenness of the current distribution can be adjusted by changing the height of the convex part. The current density at the corner of armature is very large in the plane-rail and the concave-rail types, which results in stress concentration and probably damage of armature or rail surfaces.