电磁发射用一体化C形电枢的结构设计

Geometry Design of Monolithic C-shaped Armature for EML System

为对电磁发射用一体电枢结构进行合理的设计,选取C形一体电枢的部分结构参数作为研究目标,通过对电枢进行建模仿真,对一体电枢的结构参数变化对其电流密度分布、与轨道接触面上的接触压强分布进行了计算,并通过对比获得了部分结构参数变化对电流密度和接触压强分布的影响规律。电枢的两翼厚度和头部厚度对通过电枢的电流密度和电枢上产生焦耳热分布的最大值区域有明显影响,而长度增加对这些特性分布的幅值和位置影响不大。30mm尾翼长的模型中,接触压强较大的主要范围为其后半部分,与实验结果比较一致。设计制作了不同结构的铝合金电枢,进行发射实验,并测量通过电枢的发射电流、观测发射后的电枢轨道接触面状况。发射实验结果显示,加长电枢两翼长度,可以一定程度的扩大电枢-轨道良好接触区域的面积,头部厚度7mm的铝电枢在20mm口径的发射装置中可以满足通流250kA以上不至于产生物理破坏。通过对计算和实验结果的分析比较,提出进一步工作展开的方向应为将数值计算和实验现象建立直观的联系。

In order to design the monolithic armature for EML system,some structure parameters of C shaped monolithic armature was chosen to be researched. By numerical modeling and calculating,the current density distribution in armature,the contact pressure distribution on the contact surface between armature and rail,and their relationship with the change of structure parameters were obtained. The thicknesses of armature＇s head and wings had significant relationship with the max value distributing area of current density and joule heat in armature,which showed no obvious relationship with the lengths of wings. In the model with 30 mm wing,the bigger contact pressure mainly distributed on the back half of the contact surface,which agreed with the experimental results. The electromagnetic launch experiments were performed using aluminum alloy armatures originally designed and manufactured,the driving currents were measured,the status of contact surfaces of armatures and rails were observed. The result showed that,by lengthening the wings,the well contacted area between armature and rail could be increased at some extent. The aluminum alloy with 7 mm thick head could carry current of 250 kA in 20 mm caliber EML launcher without serious physical damage. By comparison and analysis of the research results,it is suggested that further work should focus on establishing the connection between the numerical results and experimental phenomenon.