电磁发射装置电-磁-热场分布的分析与仿真

摘要

For exploring the thermal ablation phenomenon in electromagnetic emission,the models of electromagnetic emission and electrical contact resistance contact layer is constructed,electric -magnetic - thermal field coupled equations is deduced,using finite element numerical method to gain the current density and the magnetic flux density and temperature distributing profile between the rail and armature. Calculations show that electromagnetic emission process is actually electric - magnetic -thermal field coupling process. The contact resistance is one of the main causes of heat loss in electromagnetic emission. The contact resistance produces great current density in the contact surface area of rail and armature,which causing material ablation easily.%为探讨电磁发射过程中出现的热烧蚀现象，构建了电磁发射及电接触层接触电阻的模型，推导出电-磁-热场耦合方程，采用有限元数值计算方法得到了在脉冲电流激励下，轨道和电枢间电流密度、磁感应强度及温度的分布图。计算过程表明：电磁发射过程实际是电-磁-热场的耦合过程，接触电阻是造成电磁发射热损耗的主要原因之一，接触电阻使得轨道和电枢接触表面区域的电流密度极大，容易造成轨道材料的烧蚀。