外加纵向磁场移动焊接熔池流场和传热耦合分析

Coupled Analysis of Fluid Flow and Heat Transfer in Moving Weld Pool under External Longitudinal Magnetic Field

建立了外加纵向磁场移动(GasTungstenArcWelding,简称GTAW)三维熔池中的电磁场、流场与热场的数学模型,利用AN SYS软件所提供的多耦合场分析功能,对熔池中电流密度与通电线圈产生的磁场分布,以及外加纵向磁场作用下移动GTAW三维熔池的流场与热场进行了研究.研究发现,熔池中的电流密度在熔池中心以外的某一环形区域达到最大值,空心圆柱线圈产生的磁场可以近似为纵向磁场,而且在外加纵向磁场作用下,焊接熔池液态金属做高速旋转运动(0 23m/s),可使熔池呈现"宽而浅"的形状.

Mathematical models of electromagnetic field, fluid flow and heat transfer the of three-dimensional moving gas tungsten arc (GTA) weld pool with external longitudinal magnetic field were established. Using the multi-coupled analysis function of AN-SYS, distributions of current density and magnetic field as well as fluid flow and heat transfer in the moving weld pool were systematically studied. The results show that under the control of external longitudinal magnetic field, the welding current in the weld pool reaches its maximum in a annular area at some distance from the weld pool center. The magnetic field produced by a hollow cylindrical coil is approximately longitudinal. Liquid metal rotates in the weld pool and the rotating speed is as high as 0.23 m/s or so. The shape of the weld pool appears as wide and shallow.