Analysis Of Driving Coil Structure And Acceleration Effect Of Single Stage Induction Coilgun

Electromagnetic launch is a potential development direction in aerospace,military,high energy physics and other fields.Compared with the traditional gun,the electromagnetic launch is a method that uses the pulse electromagnetic force to launch the carrier to achieve high speed.Electromagnetic launch is mainly divided into rail type,coil type and reconnection type according to different structure and launch principle.Among them,induction coilgun is one of the most important research directions in electromagnetic launch in recent years.There is no friction between the projectile and the barrel,and it has the advantages of simple manufacture,flexible adjustment and high energy conversion efficiency.The exit speed and launching efficiency are the key factors to evaluate the coilgun system.A large number of researchers have proposed relevant research schemes from the aspects of power storage,control strategy,materials,etc.But for the drive coil winding method on its launching efficiency,optimization of existing research level is limited and incomplete.As the most important part of the coil gun system,the structure and material of the drive coil determine the launching efficiency of the whole system.The electromagnetic field generated by the driving coil of the traditional structure is uniformly distributed and the magnetic field gradient is single.Changing the winding structure of the driving coil will change the magnetic field distribution of the coil and the magnitude of the electromagnetic force received by the armature.Therefore,based on the firing mechanism of the coilgun,this paper proposes a method to improve the winding structure of the coil,aiming at increasing the exit speed of the armature.Firstly,a numerical simulation model of a small single-stage induction coilgun is established based on the basic principle of electromagnetic coilgun.Based on this,the dynamic working process of the single-stage induction coilgun is analyzed.Then the influence of key factors such as external circuit parameters,optimal trigger position,coil material and geometric size on the exit velocity is studied.Under the condition of optimal parameters,the traditional winding coil is gradually improved into three types of driving coils,which are table type,conical type and concave type.The distribution of electromagnetic field,axial electromagnetic force received by the armature and induced current density on the armature are compared and analyzed.Based on this,the influence of the method on the exit speed is further studied.The simulation results show that when the total winding number of the control coil is certain,the exit speed of the armature increases gradually with the improvement of the winding structure,which is in line with the theoretical expectation.Finally,the method of improving the winding structure is quantitatively analyzed,and the applicable characteristics of the improved method are summarized.When the traditional winding process is changed to concave shape,the exit speed gradually increases,and when the radian of concave shape winding structure gradually increases,the exit speed slightly decreases.Based on the above research,this improved method provides a new way to increase the firing speed of the coilgun.