Three-dimensional modeling of turbulent weld pool convection in GTAW processes

Three-dimensional turbulent weld pool convection in a gas tungsten are welding (GTAW) pool is simulated using a high Reynolds number k-epsilon model. The k-epsilon model is suitably modified to account for the morphology of the solid-liquid interface. Melting and solidification occurring during the welding process are modeled using a modified enthalpy-porosity technique. Key issues regarding turbulent transport in a GTAW process are highlighted by comparing the results from the turbulence modeling with the corresponding ones from a laminar model, keeping all process parameters unaltered. A scaling analysis is also performed to obtain order-of-magnitude estimates of certain key features of a turbulent weld pool. The scale analysis predictions show good agreement with the numerical results.