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An electromagnetic rail launcher (ERL) is essentially a high-speed linear motor, which can accelerate projectiles from milligrams to several kilograms and the velocities of which can reach more than several kilometers per second. In this article, the dynamic electromechanical characteristics of an ERL with the cross-section of plane, convex, and concave rails under different conditions of frictional coefficient and channel cooling are investigated. The kinematic characteristics of armatures and the stress distribution of three types of rails are compared. The mathematical relation between the frictional coefficient, the sliding time, and the armature speed in an ERL with three types of rails is obtained. The equations for the frictional coefficient, the sliding time, and the displacement of armature in an ERL with three types of rails are obtained. Under the same frictional coefficient condition, the velocity and displacement of armature in an ERL with a convex rail are the largest. The peak stress in a plane rail during one shot period is the greatest. In light of obtaining a higher armature velocity and moderate stress in a rail, the ERL with convex rails is the best one. [ABSTRACT FROM AUTHOR]

Thermal characteristics were studied for the cross section of plane, convex, and concave rails by channel cooling and surface/channel cooling at repetition rate: 10 and 20 shots/min, respectively. The simulations were all done for 10 sequential shots. During 10 shots time, the peak temperature in three type rails by two cooling approaches is much lower than melting point of rail. Peak temperature in concave rail by two cooling conditions is the highest at the same moment within 10 shots time under identical conditions. Maximal temperature in three type rails by two cooling methods, all increases exponentially with time. In light of obtaining lower peak temperature in rail, convex rail is better than plane and concave rail. In terms of avoiding ablation and gouging, surface/channel cooling is better than channel cooling. [ABSTRACT FROM AUTHOR]