but not least, the presence of the laser beam itself. Typical temperature gradients encountered are of the order of 10 6 ะ A direct computer simulation technique is developed to analyze quantitatively the influence of the fluid flow and heat transfer in the K/cm. Power density of 0.1 to 20 MW/cm 2 is typically used transient development of a laser drilled hole in a turbine airfoil in laser drilling wherein momentum transport or convecmaterial, where the material removal is effected by vaporization tion is significant. Vaporization and gas dynamical effects and melt ejection. The coupled conduction heat transfer in the solid become predominant too. Numerical modeling helps unand the advection-diffusion heat transfer in the liquid metal, the derstand the competing complex phenomena that occur fluid dynamics of melt expulsion and the tracking of solid-liquid and liquid-vapor interfaces have been mathematically modeled for simultaneously during drilling, either individually or in the 2D axisymmetric case. The donor-acceptor cell method using concert and lets one gauge their relative importance as the volume of fluid approach is used to solve the complex problem well. and a versatile numerical code has been developed. It takes into A schematic representation of the LD process is shown account all thermophysical properties including latent heat of vaporin Fig. 1. A laser beam is produced and directed toward ization, gravity, and surface tension driving forces. The novelty of this model is to treat the melted pool surface as a deformable free a metal target, which absorbs some fraction of the incident surface. The impressed pressure and temperature on the melt surlight energy. Vaporization that occurs after melting creates face is provided by an 1D gas dynamics model whose vaporization a back (recoil) pressure on the melt surface which pushes kinetics are also discussed. The model is used to simulate drilling the melt away in the radial direction. Thus, the material for a number of spatially and temporally varying laser intensity is removed by a combination of vaporization and liquid profiles. It is found that resolidification of melt (recast formation) occurred throughout the pulse interval and had significant effect expulsion. The physical processes that take place during on the developing hole geometry, while the effect of vaporization material removal are heat transfer into the metal, thermomaterial removal on the hole geometry is found to be small. Comdynamics of phase-changes, and incompressible fluid flow parison of the simulated results indicates the material removed per due to the impressed pressure, with a free boundary at the