A generalized thermal modeling for laser drilling process .1. Mathematical modeling and numerical methodology

Conduction and advection heat transfer in the solid and liquid metal, respectively, the free surface how of the liquid melt and its expulsion, the tracking of the solid-liquid and liquid-vapor interfaces with different thermo-physical properties in the two phases and the evolution of latent heat of fusion over a temperature range are mathematically modeled for the two-dimensional axisymmetric case in the transient development of a laser drilled hole where the impressed pressure and temperature on the melt surface is provided by a one-dimensional gas dynamics model. Significant improvement made to our earlier melting and solidification submodel is discussed that comprises a temperature transforming model on a fixed grid system. The resulting advection-diffusion equation's compatibility with the present fluid flow simulation model is described. The mathematical formulation of the submodels and the numerical methodology is presented. (C) 1997 Elsevier Science Ltd.