全熔透钨极惰性气体保护电弧焊熔池流动与传热动态过程的数值分析

Numerical Analysis of Dynamic Fluid Flow and Heat Transfer in Fully-penetrated GTAW Weld Pool

针对原有钨极惰性气体保护电弧焊熔池形态模型存在的问题,采用液体分数法处理了固液相变潜热,利用完备的熔池表面变形方程组描述了熔透熔池上、下表面变形方程的耦合作用,进一步提高了熔池形状尺寸与熔池表面变形的数值计算精度。在此基础上,对全熔透GTAW焊接熔池中的流体流动与传热过程和熔池形状的动态变化过程进行了数值模拟,展示了熔池形态的瞬时演变特性。

To solve the existing problems of the previous models for GTAW weld pool behaviors, the latent heat of phase-change is treated by means of the method of liquid-fi＇action, and the coupled interaction between the upper and bottom surface deformation equations of fully-penetrated weld pool is described by employing the completed weld pool surface depression equations. The prediction precision is further improved for the weld pool geometry, dimension and surface deformation. Based on the modified model for fully-penetrated GTAW weld pool, the dynamic variation processes of fluid flow and heat transfer as well as weld pool geometry are numerically simulated, and the transient characteristics of weld pool evolution behaviors are illustrated.