基于四组对比模型的线圈式电磁炮弹丸速度分析

Velocity Analysis for Coil Electromagnetic Projectile Based on Four Comparative Models

电磁发射是一种利用脉冲电磁力作为驱动力的新式高速发射技术.它是一个有着电磁场、结构场、温度场等的强耦合过程,弹丸出口速度与系统若干因素都有关,有限元法是目前分析电磁发射物理过程的主要方法之一.本文主要阐述了线圈式电磁炮的工作原理,建立其有限元分析模型,并通过静止模型、位移模型、速度模型、完整运动模型分别对相同参数下的弹丸发射实例进行研究;探究了由位移导致的磁场衰减和弹丸运动产生的动生电动势分别对弹丸感应涡流、磁场分布、弹丸所受电磁力及弹丸运动速度的影响.结果表明:在低速运动状态下,磁场衰减对弹丸速度的影响较小,动生电动势为弹丸速度衰减的主要因素;在高速运动状态下,磁场衰减和动生电动势对弹丸运动的影响较大.通过对线圈式感应型电磁炮出口速度的影响因素探究,为今后对于电磁发射装置的优化设计提供理论分析支撑.

Electromagnetic emission(EMT)is a novel high speed emission technology through using the pulsed electromagnetic force as driving force.It is a stronger-coupling process with the electromagnetic field,the structural field,the temperature field,etc.The exit velocity of projectile is related to several factors of the system.Commonly,the method of finite element is one of the main methods to analyze the physical process of electromagnetic emission.The working principle of the coil electromagnetic gun is expounded,the finite element analysis model is established,and the instance of the projectile launch is studied under the same parameters through the static model,the displacement model,the velocity model and the complete motion model,respectively.Meanwhile,the attenuation of the magnetic field caused by the displacement is explored and the motional electromotive force of projectile motion influences on the eddy current,the distribution of magnetic field,the electromagnetic force borne by the projectile and the velocity of projectile motion,respectively.The results show that the attenuation of magnetic field has little influence on the velocity of projectile,and the motional electromotive force is the main factor for the velocity attenuation.The attenuation of magnetic field and the motional electromotive force have greater influence on the projectile motion under high speed motion.The influence factors are explored on the exit velocity of electromagnetic gun based on thecoil induction type.It provides the support of theoretical analysis for the optimal design of electromagnetic launcher in the future.