Numerical Analysis of Heat Transfer and Fluid Flow in Keyhole Plasma Arc Welding

Abstract

Modeling and simulation of fluid flow and heat transfer in keyhole plasma arc welding is of great significance for optimizing the process parameters, and obtaining deep insight of the process mechanisms. In this study, a three-dimensional transient model is established to analyze numerically the evolution of the weld pool, the keyhole shape and dimensions, and the fluid convection and temperature profiles in a PAW weld pool. The keyhole boundary is tracked by the VOF method, and the enthalphy–porosity technique is used to model latent heat during melting and solidification. The temperature distribution, fluid velocity field, and keyhole formation are computed. The dynamic development of keyhole geometry and its interaction with the weld pool are numerically simulated. The model is validated through comparing the predicted fusion lines of the PAW weld to the experimentally measured ones.