外加高频纵向磁场作用下的TIG焊电弧数值模拟

基于局部热平衡状态假设，建立外加高频纵向磁场作用下的钨极惰性气体保护焊的电弧稳态三维数值模型.通过对麦克斯韦方程组、连续性方程、动量守恒方程、能量守恒方程的耦合求解，得到了电弧的温度场、流场和压力场等计算结果.结合法拉第电磁感应定律，考虑时变磁场的电磁感应效应，引入感应电场，解释了高频纵向磁场作用下的电弧收缩现象.结果表明，外加高频纵向磁场感应产生环向电场，形成环向电流，环向电流与外加纵向磁场作用产生径向洛伦兹力，导致电弧收缩.

Numerical simulation of TIG welding arc with extra high-frequency longitudinal magnetic field

A three-dimensional (3D) numerical analysis model of tungsten inert gas welding arc with extra high-frequency longitudinal magnetic field was developed based on the local thermodynamic equilibrium assumption. With this method, the temperature field,velocity field and pressure field of arc plasma were investigated by solving the Maxwell equations, continuity equation, momentum conservation equation and the energy conservation equation. Combined with Faraday''s law of electromagnetic induction, electromagnetic induction effect of extra high-frequency longitudinal magnetic field was taken into account. The mechanism of arc contraction in extra high-frequency longitudinal magnetic field was clarified successfully. Simulation results showed that extra high-frequency longitudinal magnetic field inducted circular electric field, it produced circular current, which interacted with the magnetic field to generate radial lorenz force, the arc contracted after all.