Laser evaporative heating of surface: simulation of flow field in the laser produced cavity

Abstract

Laser heating of steel surface is considered and phase change process during laser heating pulse is simulated. A two-dimensional axisymmetric heating situation is considered when modelling the physical processes involved. The flow field generated in the cavity due to an evaporating front is modelled numerically using a control volume approach. Recoil pressure developed in the cavity is computed. A turbulence model is accommodated to account for the turbulence in the evaporating vapour front. It is found that the size of the mushy zone across the liquid–solid interface is smaller than that corresponding to the vapour–liquid interface. The evaporating front emanating from the cavity generates a complex flow structure in the cavity, in which case, high velocity expanding jet is developed in the region close to the cavity wall. Recoil pressure attains high values in the early heating periods due to rapid evaporation of the cavity surface.