基于磁场方向变化的同步感应线圈发射器效率提升分析

Analysis of Improving Efficiency on Synchronous Induction Coilgun Based on the Directional Change of Magnetic Field

提升同步感应线圈发射器的能量转换效率是电磁发射研究的热点之一。电枢在运动过程中,磁场沿轴向剧烈变化,使得电枢产生了感生电流和动生电流,电枢受力不均匀。在磁场同向的条件下,电枢加速主要集中在驱动线圈电流的上升沿,电枢截面电流分布不均匀。由于驱动线圈电流的减小和电枢的运动,导致磁场迅速减小,影响了系统的发射效率。身管内的磁场变化对于电枢加速具有重要影响,通过改变线圈的电流方向,电枢初速显著提高。电枢加速主要集中在驱动线圈电流的下降沿,电枢截面电流显著增加,有利于增加电磁推力和提高发射效率。实验结果表明,磁场反向后电枢初速和效率得到了显著的提高,该方法为多级线圈发射装置的设计提供了参考。

Improving the energy conversion efficiency of synchronous induction coilgun is one of hotspots in the electromagnetic launch research.In the process of armature movement,the magnetic field changes dramatically along the axis.The induced current and motional current is generated,the force on the armature is distributed nonuniformly.For the magnetic field generated by the driving coils in the same direction,the acceleration time zone on armature mainly located on the rising time of the driving coil current,and the current in the cross section is unevenly distributed.Due to the decrease of the driving coil current and the movement of the armature,the magnetic field decreases rapidly,which affects the energy conversion efficiency.The change of the magnetic field in the barrel has great influenced on the armature acceleration.By changing the direction of the coil current,the muzzle velocity of the armature is significantly increased.The acceleration time zone on armature mainly located on the falling time of the driving coil current,and the armature current on the cross section is increased dramatically,which is beneficial to increase the electromagnetic force.The experimental results show that the muzzle velocity and system conversion efficiency are significantly improved after changing the direction of the magnetic field.This method provides a reference for the design of multi-stage coilgun.