Gas Flow Characteristics in A Laser Cut Kerf

Characterization of a supersonic impinging jet in a laser cut kerf was conducted with a Schlieren method and a Computational Fluid Dynamics (CFD) analysis to investigate the gas-dynamic effects of the jet in a cutting process. A flow separation and an associated recirculation zone occurring at the bottom of a cutting front were found. Imbalanced flow separations and recirculation zones at both side walls, and flickers of the flow inside the kerf were also observed. From the cutting experiments, it was found that better cutting performances were achievable with deeper penetration of the flow field inside the kerf.