Large-eddy simulation of laser-induced surface-tension-driven flow

The turbulent flow inside a laser-generated molten pool is investigated by an adapted large-eddy simulation (LES) model that incorporates physical considerations pertaining to the solid-liquid phase change. A single-domain, fixed-grid enthalpy-porosity approach is utilized to model the phase-change phenomena in the presence of a continuously evolving solid/liquid interface. The governing transport equations are simultaneously solved by employing a control-volume formulation, in conjunction with an appropriate enthalpy-updating closure scheme. To demonstrate the performance of the present model in the context of phase-change materials processing, simulation of a typical high-power laser melting process is carried out, where effects of turbulent transport can actually be realized. It is found that the present LES-based model is more successful in capturing the experimental trends, in comparison to the k-ε-based turbulence models often employed to solve similar problems in contemporary research investigations