Gas-assisted laser repetitive pulsed heating of a steel surface

Abstract

The present study is carried out to investigate the effect of the assist gas jet on the thermal integration due to repetitive pulsed laser heating. Air is considered as the assist gas, which impinges coaxially with the laser beam and orthogonal to a steel surface. The low Reynolds number k-ε model is introduced, based on previous studies, to account for the turbulence. A numerical scheme using the control volume approach is employed to solve the two-dimensional axisymmetric governing equations of flow and heat conduction. The transport properties of the assist gas and of the solid substrate are considered as variable. The study is extended to include two gas jet velocities and three laser pulse types. It is found that thermal integration in the solid substrate is possible for a low-intensity power ratio of the repetitive pulses and the influence of the assist gas jet on the temperature profiles is almost insignificant.