基于电接触特性的电枢臂形状优化设计

电枢与轨道之间的接触特性直接影响电磁轨道发射器工作过程中电枢与轨道接触面上的接触压力分布和电枢与轨道上的电流分布,进而影响发射器的焦耳热分布,从而影响电磁轨道发射器的性能和寿命。为了改善发射器电枢与轨道之间的接触特性,对非过盈配合状态下电枢膛内运动过程进行了仿真,得到了电枢的运动特性和接触压力随时间变化情况。选取电枢膛内运动过程中与轨道之间接触状态最严峻的典型时刻,基于Cooper-Mikic-Yovanovich电接触理论和“1 g/A”经验法则分析枢轨间接触压力,设计了期望电接触特性,并针对典型时刻的接触状态基于反向加载法设计了电枢的过盈尺寸和形态。对装配过盈电枢和非过盈电枢的发射器进行仿真研究,比较其在典型时刻的性能。结果表明,采用改进的电枢结构可以使电枢与轨道接触面上的电导率分布更加均匀,改善了电枢与轨道的接触状态,缓解了电枢区域电流分布集中现象和焦耳热集中现象,进而延长发射装置寿命。

Optimization Design of Armature Arm Shape Based on Electrical Contact

The electrical contact characteristics between the armature and the track directly affect the contact pressure distribution on the contact surface and the current distribution on the armature and the track during the launch process,and further affect the Joule heat distribution,the performance and the longevity of the railgun. In order to improve the electrical contact characteristics between the armature and the track,the work progress of the railgun with non-interference armature was studied,and the laws of the velocity,acceleration,displacement ang contact pressure changing with time were obtained. The moment with the worst contact state was selected as a typical moment. Based on the Cooper-Mikic-Yovanovich contact theory and the "1 g/A" empirical rule,the contact pressure between the armature and the rail was analyzed,and the desired electrical contact characteristics was designed. The armature interference parameters were optimized based on the reverse loading method. The railgun with non-interference armature and interference armature was simulated to compare its performance at typical moments. The results show that the improved armature structure can make the conductivity distribution more uniform,improve the contact characteristics,reduce Joule heat concentration and extend the life of launcher.