Numerical Simulation of Droplet Transfer of AZ31B Magnesium Alloy Based on FLUENT

According to electromagnetic theory and fluid dynamics theory, the AZ31B magnesium alloy GMAW droplet transfer was simulated in the paper, by VOF model of FLUENT software to track the free interface of gas-liquid, use UDF order to add source term of momentum and energy equation. The simulation results show that when welding current is 100 A, the type of transfer belongs to globular transfer, and the type of droplet transfer of 280 A belongs to projected transfer; the critical transition current from globular transfer to projected transfer is about 220 A. With the increase of welding current, the diameter and length of droplet become small, the ratio of long axis length to the short axis length become more and more small, and the shape of droplet changes from long-oval to round. The neck part produces the maximum pressure, maximum pressure coefficient, maximum droplet velocity; the temperature gradient increases along with the axial direction; those factors will accelerate formation of the pencil tip and promote the droplet transfer.