NON FOURIER HEAT CONDUCTION IN A SEMI INFINITE BODY EXPOSED TO THE PULSATILE AND CONTINUOUS HEAT SOURCES

In this paper, the melting of a semi-infinite body as result of a continuous or pulsatile moving laser beam has been studied. It has been known that classical Fourier heat diffusion analyses fail to accurately model transient thermal responses in extremely high heat flux, low temperature, and high speed energy transport engineering applications because they assume that thermal energy transport is occurring at an infinite propagation speed. In addition, thermophysical properties such as heat conductivity coefficient, density and heat capacity are functions of temperature and material states. The enthalpy technique used for the solution of phase change problems in an explicit finite volume form for the hyperbolic heat transfer equation. This technique used to calculate the transient temperature distribution in the semi-infinite body and the growth rate of the melt pool. Temporal variation of laser beam intensity in two cases of continuous and pulsatile heat flux considered. In order to validate the numerical results, comparisons made with experimental data. Finally, the results of this paper compared with similar problem that has used the Fourier theory. The comparison shows the influence of infinite speed of heat propagation in Fourier theory on the temperature distribution and the melt pool size.