Numerical Simulation Of Railgun Rail Characteristics

Electromagnetic railgun is a new type of launching mode which uses electric energy as energy.It has great potential in improving the launching performance and has become a hot research in recent years.As one of the important parts of the barrel,the rail deformation affects the launch stability of the railgun.Scholars have mostly studied the deformation of rail by analyzing correlation between the load and the deformation of the rail through theoretical calculations.However,the research on how to reduce the deformation remains to be improved.In this paper,the finite element simulation and theoretical analysis are used to analyze the deformation and electromagnetic force of two kinds of different cross-section railgun during launching,in order to determine which cross-section is more suitable for reducing the rail deformation.The main work of this paper is as follows:(1)Based on the theoretical analysis of the ampere force on the rail,the expression of the volume force of the rail and the armature in the electrified state is obtained.The results show that when the railgun is working,the armature interacts with the rail.The force on the rail is not all from the armature,but also from the other side of the rail.In general,the internal force of the overall system of the railgun is in balance.(2)Aiming at the parameters of current transfer area and barrel cross section,two kinds of railgun models with comparability are established.Furthermore,the preconditions for finite element simulation,such as material parameters,structure contact mode and boundary conditions,are set up.(3)The electromagnetic structure field of electromagnetic emission is simulated by finite element method.The volume force distribution,current distribution and structural deformation of the two kinds of rails are obtained.The results show that the launch thrust of circular rail and armature is no less than that of square rail and armature,and the distribution of volume force inside armature is more uniform.Circular rail is better than square rail in resisting structural deformation,in which the regional expansion deformation in contact with armature is about 24% smaller than that of square rail.Circular rail has more advantages in structural stability under the same current condition.(4)The relationship between the rail shape variable and the rail section shape is studied by using the finite element simulation method.The results show that with the increase of the curvature of the rail section,the reduction of the rail shape variable presents a certain regularity.