Incompressible SPH simulation of weld pool convection with molten metal droplets in a GMA welding

In this study, the convective flow in a weld pool during a GMA welding process was clarified by a numerical simulation using an incompressible smoothed particle hydrodynamics method. The computational domain of this simulation was a two-dimensional vertical section of a base metal along the welding direction in a system whose consumable electrode moved. The simulation revealed that the molten metal droplet fell into the weld pool and generated a wave which travelled backward. When the wave hit the solid bead, it swelled up as it solidified generating a wavy surface, which is observed in actual GMA welding. The flow inside the weld pool was also simulated. Both the height of the formed reinforcement and the depth of the penetration agreed with experimental results, which presented the validity of this simulation.