Electro-dynamic force analysis of armature-rail tight contact in electromagnetic launcher

Large transient electro-dynamic force is generated by high pulse current in electromagnetic rail-launcher, which pushes the armature sliding along the rail until it reaches high muzzle velocity. To realize the target velocity, the armature-rail should contact tightly under appropriate pressure, which is also aroused by electro-dynamic force. The contact pressure varies according with the variety of transient electro-dynamic force. To acquire the detailed information about electro-dynamic force of armature-rail, a finite element model is built to analyze the electro-dynamic force by multi-physics fields coupling method. This method takes infinite field effect into account. The experimental object is an electromagnetic rail-launcher with C-shaped solid armature, and the experimental results verify that a new kind of optimized armature can keep the contact with the rail tightly at high velocity. As a result, the armature´s sliding velocity has been increased before armature transition happens.