Study of thermal behavior and fluid flow during laser surface heating of alloys

Abstract

Transient and steady state laser melting problems are numerically simulated for steel and Al-4.5% Cu. Enthalpy and apparent capacity methods are used to solve the energy equation, and the momentum equations are solved in the liquid domain and mushy zone with the SOLA-VOF algorithm. Using a laser with a top-hat profile, a wide range of studies are performed by varying the beam power density and the beam radius. The streamline plots show that the flow pattern is dependent on the strength of the rotating cell along with heat flux. It is found that the shape of the pool, the surface velocity, and the surface temperature are quite different from those without convection in the mushy zone. Convection in the mushy zone plays an important role in heat transfer and fluid flow during laser melting.