Improvement of numerical simulation for GMAW based on a new model with thermocapillary effect

In this paper, we present a numerical investigation about the metal transfer of GMAW with a new model based on the phase field model. Unlike most published work, the thermocapillary effect and mixture energy resulting from the new research of multiphase fluids are taken into model of phase transfer and interface change which is different from volume of fluid method (VOF) that has been widely used in welding problem. We discretize the whole model including continuity condition, Navier–Stokes equation, phase field model, energy equation and Maxwell's equations with a continuous finite element method in space and a midpoint scheme in time and a penalty formulation is applied to the continuity condition due to the stability in the pressure. Metal transfer of GMAW with pulse current is computed as a numerical example where the numerical result have been verified by the experimental data obtained by using a high-speed camera. Moreover, we also compare the numerical results with and without considering the thermocapillary effects to show that the new model has a higher precision in predicting the droplet in welding.