Pitch Effect of Helical Coils of Electromagnetic Forming

Wenting Zhang,Hang Zhou,Xinhui Zhu,Lijun Zhou,Shuixiang Li,Meng Yang,Xiaoguang Liang,Xianqi Song

doi:10.1109/access.2020.3037176

Abstract

At present, solenoid (helical) coils are widely used in various researches, especially electromagnetic forming (EMF), due to their advantages of simple manufacture and high magnetic field strength. However, in the study of EMF, there are still some defects in the high precision calculation of solenoid coils in the magnetic field the main reason is that the solenoid coil is of non-axisymmetric structure, which is generally equivalent to the 2-D or 3-D axisymmetric structure in practical research. Not only can it ignore the effect of the pitch effect of the solenoid coil, but also causes a certain deviation in the calculation of the magnetic field. Hence, this paper establishes 5 helical coils and 3-D axisymmetric finite element coils models with different layers for comparative analysis. The simulation results show that the magnetic flux density distribution deviation of helical coil and the 3-D axisymmetric coil is small and can be ignored when the coil layers are 1 or 2 layers. However, the number of linear circles increasing, the deviation between the two increases obviously. Therefore, in the study of EMF, the effect of solenoid coil pitch effect on magnetic field calculation can be ignored when the layers, radius and pitch of helical coils are used less whereas the effect of solenoid coil pitch effect on magnetic field calculation must be considered when the layers, radius and pitch of helical coils are used more.

Highlights

Solenoid coils have been widely used in various researches due to their advantages of simple manufacture and high magnetic field strength, such as permanent magnet machines [1,2], electronic transformers [3], medical implants [4], fluid dynamics [5,6] and Electromagnetic forming (EMF) [7,8,9]
Due to the non-axisymmetric structure of the helical coil, it is very difficult to establish the actual helical coil model, which eventually leads to a sharp increase in the high precision calculation of the magnetic field, and the simulation results cannot converge
It can be seen that the maximum magnetic flux density of the helical coil is 3.96 T, and the maximum magnetic flux density of the 3-D axisymmetric coil is 3.93 T

Summary

INTRODUCTION

Solenoid coils have been widely used in various researches due to their advantages of simple manufacture and high magnetic field strength, such as permanent magnet machines [1,2], electronic transformers [3], medical implants [4], fluid dynamics [5,6] and Electromagnetic forming (EMF) [7,8,9]. In the study of EMF, the 2-D or 3-D axisymmetric equivalent model of solenoid coil reduces the calculation amount and makes it easy to solve, the influence of the non-axisymmetric structure of solenoid coil on the magnetic field generated by it is ignored. Thereby, to solve these problems, this paper adopts SOLIDWORKS drawing software to build 5 actual helical coil models with different layers and analyzes the reasons for the difference of winding coils in engineering practice from the perspective of principle. Since EMF involves the coupling process of transient multiple physical fields, so the current simulation methods are mainly included loose coupling, sequential coupling, and full coupling

THE INTERLAMINAR TRANSITION AND THE OUTGOING MODE

ONE LAYER OF HELICAL ADN 3-D SYMMETRIC COIL MODEL

MULTULAYER HELICAL AND 3-D SYMMETRIC COIL MODEL

THE SIMULATION RESULTS OF CASE 1 AND CASE 2

THE SIMULATION RESULTS OF DIFFERENT PITCH AND RADIUS

CONCLUSION