Modeling of frictions on keyhole walls during vapor flow in laser welding

The vapor flow parameters are numerically calculated inside a keyhole induced during deep penetration laser welding,. The laser intensity locally absorbed on the keyhole wall is obtained by a ray-tracing procedure and the surface temperature is then computed. The numerical solution of the compressible Navier-Stokes equations in a steady state case is obtained, by using the local vapor ejection velocities and the ablation pressures are considered as boundary conditions. Among the vapor parameters, the shear stress distribution on the keyhole walls is considered. This allow the study of the melted bath movement induced by the friction effects of the vapor with the liquid.