轨道炮弹丸所处强磁场环境屏蔽设计与仿真

针对电磁发射过程中产生的脉冲强磁场对发射包内电子器件产生较强干扰问题，采用 COMSOL中 PDE模块对电磁发射过程中的速度趋肤效应进行仿真计算，建立轨道炮的面电流分布模型和脉冲电流模型；采用趋肤效应理论分析电磁屏蔽原理，建立了屏蔽效能评估方法，并设计了一种屏蔽体模型。分别采用导电、导磁材料设计了单层、多层组合屏蔽体，用 COMSOL中磁场模块计算离弹底不同距离处的强磁场屏蔽效果，得出在离电枢较近时，导电材料与导磁材料的屏蔽效能较低，屏蔽体距离电枢越远时，导电材料的屏蔽效能不变，导磁材料的屏蔽效能逐渐提高，距离电枢100 mm时屏蔽效能达到34 dB。轨道炮磁场的低频特性使得导电材料的屏蔽效能较低，高磁通密度使得导磁材料的屏蔽效能较低，得出弹丸内智能电子元器件应置于远离电枢的弹头。

Simulation of In-bore High Magnetic Shielding for Railgun Projectile

The pulsed high magnetic field during electromagnetic launching will have a significant im-pact on electronic components in projectile. Simulated is PDE module simulating the speed skin effect during railgun launching in COMSOL with a surface current distribution model and pulse current model of the railgun built. The skin effect theory is used to analyze the electromagnetic shielding principle with the shielding effectiveness evaluation method established and a kind of shield model designed. The high conductivity material and high permeability material were used respectively to design single-layer,multi-layer composite shield with magnetic field module in COMSOL used to simulate the shiel-ding effect at different distances from the bottom of projectile. When the shielding is near the arma-ture,the shielding effectiveness of high conductivity material and high permeability material are all poor;or when the shielding is farther away from the armature,the shielding effectiveness of the high conductivity material is invariant with the shielding effectiveness of the high permeability material gra-dually improved with the shielding effectiveness being over 34dB within 100mm from the armature. The low frequency feature and high magnetic flux density characteristics limit the shielding effectiveness of high conductivity material and high permeability material,so the electronic components in projectile should be placed in warhead away from the armature.