封装对螺旋线圈发射器互感梯度的影响  

Effects of shielding on helical coilgun inductance gradient

作　　者：刘振祥[1] 杨栋[1] 蒋雅琴[1] 沈志[1] 杨丽佳[2] 欧阳建明[1] 

机构地区：[1]国防科技大学理学院,湖南长沙410073 [2]国防科技大学光电科学与工程学院,湖南长沙410073

出　　处：《国防科技大学学报》2013年第5期135-139,共5页Journal of National University of Defense Technology

基　　金：国家部委资助项目

摘　　要：互感梯度是决定线圈炮加速力的主要因素。本文以螺旋线圈炮为例,建立了计算互感梯度的二维有限元模型,对四种不同属性的封装材料和封装尺寸对互感梯度的影响做出了分析和比较,并给出了不同的封装材料及尺寸下封装的电流密度和磁场分布图。分析表明,互感梯度受到封装材料电导率和磁导率的双重制约。电导率决定了封装中感应涡流的大小;磁导率决定了对磁场的加强程度。减小封装与线圈的间距,导磁材料的磁场加强效果更好,而导电材料的涡流效应也更明显;增加封装的厚度,导磁材料可以更好地增强磁场,但由于电阻更小,导电材料涡流效应更明显。为了实现互感梯度的最大化,可以在减小封装与驱动线圈间距并增加封装厚度的情况下,使用高磁导率的硅钢片制作封装,硅钢片的厚度应该尽量小,从而削弱涡流效应。The inductance gradient is the most important parameter for coilgun design. By establishing a two-dimensional finite element model, effects of four shield materials with different dimensions and distance between coils and shield on inductance gradient were investigated. The coils current distribution and magnetic field distribution under different shields were presented. Analysis shows that the inductance gradient is affected both by material conductivity and permeability. The conductivity determines the induced eddy current in the shield. The permeability determines the degree of strengthening the main magnetic field. By reducing the distance between driving-coils and shield, the magnetic materials enhance the magnetic flux better, but more eddy currents are induced in the shield conductor. By increasing the thickness of the shield, the magnetic materials enhance the magnetic flux better, but more eddy currents are induced in the conductive materials due to the decreasing resistance. In order to achieve the maximum inductance gradient, high permeability silicon steel sheets can be used as the shield, the distance between coils and shield should be reduced, and the thickness of silicon steel sheets should be as small as possible to reduce eddy current effects.

关 键 词：电磁发射 线圈炮 封装 互感梯度 

分 类 号：TM303.1[电气工程—电机]