Entropy generation analysis of laser evaporative heating

Abstract

Laser pulse heating offers considerable advantages over the conventional heating methods. This is due to their operational precision and local treatment. In order to improve the energy efficient processing, entropy analysis of the laser heating is essential. In the present study, laser pulse heating with evaporation at the surface is presented analytically. The entropy due to laser step input pulse intensity is formulated and entropy generation number inside the substrate material is computed for different heating periods. It is found that the entropy generation increases in the early heating period and this case is more pronounced as the depth below the surface increases towards the solid bulk. The behavior of the entropy generation number is similar to that corresponding to the entropy generation rate.