轨道与电枢间运动电磁场分布的数值计算

摘要

To research the situation of current density distribution between the rail and the ar-mature during the process of electromagnetic emission,the relationships between the electro-magnetic parameters and armature moving velocity were derived by use of Maxwell electromag-netic theory.The convection diffusion equations for electromagnetic field in Cartesian coordi-nate system were set up.The convection and diffusion terms in convection diffusion equation were decomposed by means of the operator splitting scheme,and the parabolic and hyperbolic equations were all solved by use of the finite difference method.Calculations showed that the operator splitting scheme can effectively solve the electromagnetic convection-diffusion equa-tion,and this method is stable and convergent.The calculation results with the examples showed that when the armature moves at high velocity,the current density between the local area of armature and the rail is the maximum and it is easy to give rise to the erosion in local re-al rail material.%为探讨电磁发射过程中轨道和电枢间电流分布情况，根据 Maxwell 方程推导出电磁场参数与速度之间的关系，建立了直角坐标系下的电磁场对流扩散方程，采用算子分裂格式对对流扩散方程中对流项和扩散项进行分解，分别对抛物型和双曲型方程采用有限差分法进行求解。计算过程表明算子分裂格式能有效求解电磁场对流扩散方程，算法稳定，收敛性好。结合实例的计算结果显示，当电枢高速运动时，在轨道和电枢局部区域的电流密度极大，容易造成轨道材料的烧蚀。