Numerical analysis of dual-phase-lag heat transfer for a moving finite medium subjected to laser heat source

• Investigate heat transfer in a moving finite medium exposed to laser heating based on the DPL model.
• Solve the hyperbolic heat conduction equation by a hybrid numerical scheme.
• >Compare the accuracy between the numerical results and the analytic solutions.
• Study the effects of the heat-flux and the temperature-gradient phase lags.

To accommodate the micro-structural effect, this work applies the dual-phase-lag (DPL) heat transfer model to explore the transient heat transfer for a moving finite medium under the effect of a time-dependent laser heat source. Laser heating is modeled as an internal heat source. A numerical scheme has been developed to overcome the mathematical difficulties in dealing with the hyperbolic heat conduction equation. Comparison between present numerical results and the analytic solutions for the non-Fourier case is made to verify the accuracy of the present numerical method. Additionally, the effects of different medium parameters, for example, moving velocity, phase lags values of the heat flux and temperature gradient, on the behavior of heat transfer have been examined. It is found that there exists clear phase shifts in the temperature distributions due to the medium moving velocity. The heat-flux phase lag tends to induce thermal waves with sharp wave-fronts in the medium, the inclusion of temperature-gradient phase lag smoothens the sharp wave-fronts by promoting conduction into the medium, resulting in non-Fourier diffusion-like conduction.