Plume Formation During Laser Heating of a Solid Surface

A mathematical model of the dynamics of laser-produced heating, evaporation and plume formation is presented. The condensed material model includes conduction heat transfer as well as melting and evaporation phase changes. The localized heating and evaporation caused by focused laser radiation forms a plume of mixed vapor above the material surface. The beam is absorbed and refracted as it traverses the plume, thus modifying its power density on the surface. In this work, variations of heat transfer rate during laser heating and effects of a plume formed by vapor from an iron surface are studied using an axisymmetric mass, momentum and energy transport model. The simulation results quantify the heat transfer rate in the plasma plume, heat losses due to radiation, and variations of heat input into the material.