中文摘要：

为了对多级发射达到高速时的电磁问题进行研究，以使用板状发射体和箱形线圈的多级重接式电磁发射为研究对象，推导了多级线圈电磁场和发射体涡流场的综合作用方程，利用ANSOFT电磁场有限元分析软件建立了三维有限元仿真模型并进行仿真计算。结果表明，多级线圈电流的同时存在，既改变了单级线圈的磁场分布和磁感应强度大小，也改变了发射体中局部涡流密度的大小和发射体受力的大小。这种改变与线圈电流的频率和相位差异相关，并且线圈间距越小，这种综合作用的影响越大。

英文摘要：

In order to investigate the multi-stage reconnection electromagnetic launch using the flat plate projectile and the box-shaped coils ,the synthesized equations on the electromagnetic field of the multi-stage coils and the eddy current in the projectile are analyzed and deduced. By means of the ANSOFT software for electromagnetic field finite element analysis, a three-dimensional finite element simulation model of the multi-stage reconnection electromagnetic launch is established and the simulation is performed. The simulation results show that, the coexistence of the multi-stage coil currents changes the magnetic field distribution and the magnetic flux density magnitude of the single-stage coil. The magnitude of the eddy current density in the projectile and the magnitude of the force on the projectile are also changed. These changes are relevant with the differences of the frequency and the phase of the coil currents. The less the distance between the coils is, the stronger the influence of the synthetic action is.