Finite element simulation on current distribution feature of different rail- armature structures for rail launchers under static conditions

Electromagnetic railguns can accelerate macroscopic objects to so high hypervelocity that they would be widely used in future warfare. Currently, one of the key problems about electromagnetic railguns is the discharge and ablation between armature and rails. The main reason of the disfigurement is the local ohmic heating to melting because of unevenly distributed current in the conductors´ skin. In this paper, electric current density of five typical rail-armature structures under 0m/s armature speed condition are contrastively analyzed by Maxwell 12 software. The results indicate the following: 1, the skin depth in conductors because of electromagnetic vibration is about 10mm, which makes hollow bulky conductors; 2, conductors with rectangular cross section has the most asymmetric electric current distribution; 3, the launcher with D-shaped cross section conductors has the highest quality index of the five structures. The above conclusions have important reference meaning for restraining local discharge and ablation, improving gouging, prolonging lifetime of the rail launcher etc.