Laser-epoxy interaction and plume shielding in the presence of crossflow

Abstract

The present work considers the interaction of a continuous-wave (CW) laser with carbon-fiber reinforced polymers in the presence of a subsonic crossflow. A multi-physical approach has been developed to address this computational problem. The optical model of a plume has been coupled with the flow and material response model, encompassing the formation and transport of soot particulates. At given power densities of the laser beam the gaseous component of a plume is nearly transparent to the laser beam, and the laser beam shielding by a plume arises from soot particulates. Soot particulates do not reach the outer edge of the boundary layer due to a small diffusion coefficient compared to gaseous species. These particulates are swept downstream by the crossflow, creating a favorable window for the transmission of the laser energy to the material in terms of the crossflow velocity-laser power density envelope.