Study On Launch Of Ultra High Speed Electromagnetic Gun With Multi Physical Field Coupling

During the launching process of an electromagnetic launch device,the entire device is operated in an electromagnetic temperature stress extreme multi-physical field coupling environment.The pivot rail is affected by interference preload,electromagnetic force,pivot rail gouging,friction and wear,high-speed electrical contact,and transient high temperatures,which seriously affect the electromagnetic launch performance of the device.Compared to high-speed electromagnetic railguns,the track working environment of ultra-high-speed electromagnetic railguns is more extreme,and the influencing factors are more complex.Therefore,the simulation and analysis of ultra-high-speed electromagnetic railguns has very important practical significance.This paper analyzes the characteristics of ultra high speed electromagnetic launcher from various aspects,such as electromagnetic field,temperature field,pivot rail friction and wear,and thermal fluid.The specific research content is as follows:Comparative simulation of high-speed and ultra-high-speed electromagnetic railguns was conducted,heat source calculation and analysis of electromagnetic devices were conducted,and temperature fields of two factors,such as joule heat and friction heat,were simulated.Coupled simulation with electromagnetic fields and stress fields was conducted to quantitatively analyze the characteristic differences between the two types of electromagnetic guns;To explore the impact of Young’s modulus and hardness changes with temperature on the pivot rail wear of ultra high speed electromagnetic devices,the wear characteristics of the two electromagnetic launch devices were analyzed in multiple stages of time and space distribution.Through summary,the distribution of armature wear presents a rule of tail region and attenuation towards the throat,and the total wear volume of ultra-high-speed armature is much larger than that of high-speed armature.How to maintain the good state of the armature rail of ultra-high-speed electromagnetic device is the key research content.Aiming at the friction and wear mechanism of the pivot rail,considering the influence of Joule heat,a new two-dimensional thermal fluid lubrication model for the contact interface wear of the pivot rail was created.The model focused on mechanical wear,obtaining a theoretical relationship formula reflecting the melting speed of the armature and the thickness of the metal liquefaction layer,exploring the friction and wear mechanism of the pivot rail and the evolution of the electrical contact behavior of the armature during high-speed sliding.In this paper,the simulation method is used to explore the melting wear and mechanical wear of ultra high speed electromagnetic launcher,and the distribution rules of the two types of wear are explored from multiple perspectives.This provides a theoretical basis for improving the design and application of ultra high speed electromagnetic launcher.