paper#100for16EML=Current Distribution Feature@20121026.docVIP

PAGE 6 Paper #100 for 16th EML, version@2012-10-26 Manuscript received October 26, 2012. . The authors are with Shijiazhuang Mechanical Engineering College, Shijiazhuang, 050003 China. (E-mail:  HYPERLINK mailto:lvqing-ao@163.com lvqing-ao@163.com; xiaoshan720@; lei_bin@). Finite Element Simulation on Current Distribution Feature of Different Rail- Armature Structures under Static Conditions Qing-ao Lv, Shi-shan Xie, Bin Lei, He Li, Chun-long Guo, and Qian Zhang Fig. 1. Sketch of a simple railgun. Abstract—Electromagnetic railguns can accelerate macroscopic objects to such a hypervelocity that they would be widely used in future warfare. Currently, one of the key problems about electromagnetic railguns is the discharge and gouging between armature and rails. The main reason of the disfigurement is that the local ohmic heat accumulates to melt because of unevenly distributed current in the conductors’ skin. In this paper, electric current distribution for five typical rail-armature structures under 0 m/s armature speed conditions are contrastively analyzed by Maxwell 12 software. And a quality index is defined to evaluate the simulation results. The conclusions is the followings: First, the current clustering in some special places of any bulky conductors’ skin is caused by the short path priority and the skin effect; Second, rail-armature conductors with rectangular cross section has the most uneven electric current distribution, and that with round cross section has the most even current distribution, but railgun with D-shaped cross section conductors has the highest quality index among the five. Third, only when the bulky conductors are split into thin strips, can the skin effect and the short path priority be restrained. The above conclusions can offer important reference meaning for restricting local ohmic heating, improving gouging, prolonging the rails lifetime. Index Terms—current distribution, electromagnetic launching, railguns, simulation INTR