Transient axis symmetric model for laser drilling

In this presentation, we focus on the melting phenomenon during laser drilling. The governing equation is the transient three-dimensional heat conduction equation for the solid substrate and for the liquid molten part boundary layer approximations of the mass, momentum and energy equations are used. The melting interface is moving and therefore need to be determined as part of the solution. In this paper, coupled BEM-FDM formulation for the transient three-dimensional heat conduction equation with moving boundary and the boundary layer formulation will be presented. The moving boundary, solid-liquid interface, appears in the surface integral of the BEM formulation. Consequently, it is easy to track. The thin layer is coupled to the solid substrate at the solid-liquid interface by the interface velocity, energy flux and temperature. To increase the efficiency of the computation, we combine the BEM formulation with finite difference method, which models the region that is far away from the melting zone. We are working towards a coupled BEM-FDM-THINLAYER model, that would be effective in simulating the process of material removal in the laser drilling.