Analysis of dual-phase-lag heat conduction in short-pulse laser heating of metals with a hybrid method

In this study, the dual phase lag (DPL) heat transfer model is applied to investigate the transient heat transfer in a thin metal film exposed to short-pulse laser heating. An efficient numerical scheme involving the hybrid application of the Laplace transform and control volume methods in conjunction with hyperbolic shape functions is used to solve the hyperbolic heat conduction equation in the linearized form of DPL model. The transformed nodal temperatures are inverted to the physical quantities by using numerical inversion of the Laplace transform. Comparison between the numerical results and the analytic solution for a short-pulse laser heating with the Gaussian temporal profile evidences the accuracy of the present numerical results. Effect of different phase lags values of the heat flux and the temperature gradient on the behavior of heat transfer is also investigated. The results show that the phase lag of the heat flux tends to induce thermal waves with sharp wave-fronts separating heated and unheated zones in the metal film, while the phase lag of the temperature gradient destroys the waveforms and increases the thermally disturbed zone.