Research On Multi Physical Field Coupling Simulation Of Enhanced Electromagnetic Railgun

Electromagnetic orbit launching technology is a very important engineering technology which was put forward at the beginning of the 20 th century and developed rapidly.After nearly 200 years of exploration and research,this technology has gradually developed and expanded,and has shown great potential in aerospace,high-pressure physics,material science,military weapons and other aspects.Especially in the aspect of weapon,there are three kinds of electromagnetic launch technology: Coil Gun,reconnection gun and orbit gun,among which orbit gun is the simplest and easy to reach super high launch speed.Compared with the traditional gun,the electromagnetic rail gun has many advantages,such as excellent performance,high export speed,good control and so on.However,the electromagnetic railgun is prone to armature melting,rail planing,armature transition and other phenomena,which seriously affects the energy conversion efficiency and exit speed of the electromagnetic railgun.In this paper,the enhanced electromagnetic railgun is taken as the research object.By studying the working mechanism of the electromagnetic railgun,the relevant mathematical model of the system is established,the MATLAB / Simulink system simulation model is built,and the performance of the multi physical field coupling simulation is analyzed through the ANSYS Workbench simulation platform with the simulation results as the initial conditions.Firstly,the structure and working mechanism of the enhanced electromagnetic railgun are studied,and the mathematical models of the electromagnetic force,friction resistance,air resistance,moving process and voltage drop of the armature rail are derived.The system simulation model is built in Matlab / Simulink by combining the electrical models such as capacitance circuit,and the enhanced electromagnetic rail is calculated by the electromechanical system simulation model of the enhanced electromagnetic railgun The current characteristic curve and armature movement result in the course of cannon work do not provide the initial condition for multi physical field coupling simulation.Then,the electromagnetic field simulation is carried out by ANSYS Maxwell under the initial condition of the current characteristic curve in the electromechanical system simulation results.The current density distribution,skin effect results,the distribution of the magnetic field strength between the tracks and the relationship between the electromagnetic force on the armature and time are analyzed.Next,in ANSYS On the workbench simulation platform,the electromagnetic field and the temperature field are coupled to carry out the temperature simulation calculation of the armature and the track,the temperature change and the temperature distribution of the track and the armature are analyzed,the temperature distribution in the track length direction is studied,and the temperature change and distribution of the armature and the track under six different voltages of 4KV,6kV,8Kv,10 kV,12kV,and 14 kV are compared and analyzed.Finally,the simulation results of electromagnetic field and temperature field are coupled with the structure field,and the elastic constraint is used to replace the package structure,and the track and armature are simulated and calculated.Under the action of electromagnetic force and resistance heat,the track expansion and armature expansion are analyzed,and the pressure between the central rails in the armature launching process is calculated by comparing the difference between the track expansion with and without armature According to the comparison between the contact pressure of the central rail and Marshall's law,the performance of the armature with different structures is analyzed.