Dual-phase lag model of thermal processes in a multi-layered microdomain subjected to a strong laser pulse using the implicit scheme of FDM

In the paper, the thermal processes occurring in the axially-symmetrical domain of multi-layered thin metal film subjected to a strong laser pulse are considered. The problem is described by the system of dual-phase lag equations (DPLE) supplemented by the appropriate boundary and initial conditions (in the form corresponding to the model considered). The possibility of domain melting is also taken into account. At the stage of numerical computations, the implicit scheme of the finite difference method is used. The problems connected with the modeling of the thermal contact conditions between sub-domains and finally the simulations of the melting and resolidification processes are discussed in detail.The continuity condition given on the contact surface is considered in the form in which the lag times are taken into account. The results confirm the differences between often presented solutions, using the dual-phase lag model supplemented by the 'macroscopic' type of these conditions. The model of melting and resolidification results from the modified form of the DPLE for which the derivative of temperature with respect to time is equal to zero. It results from the fact that the melting of pure metals proceeds at the constant temperature.