The non-Fourier effects on transient thermal response in semitransparent medium with black boundary surfaces caused by a periodic irradiation are studied. The processes of the transient coupled radiative-conductive heat transfer in a one-dimensional semitransparent slab with black boundaries are analyzed numerically. The hyperbolic heat conduction equation is solved by the flux-splitting method, and the radiative transfer equation is solved by the discrete ordinate method. The transient thermal responses obtained from hyperbolic heat conduction equation are compared with those obtained from the classical parabolic heat conduction equation. The results show that the non-Fourier effect can be important when the conduction-to-radiation parameter and the thermal relaxation time of heat conduction are larger. The non-Fourier effect can be important even at a long time after the initial transient if the periodic irradiation at boundary is oscillatory with the period of oscillation of the same order of magnitude as the thermal relaxation time of conduction.

The non-Fourier effects on transient temperature response in semitransparent medium with black boundary surfaces caused by laser pulse are studied. The processes of the coupled conduction and radiation heat transfer in a one-dimensional semitransparent slab with black boundaries are analyzed numerically. The hyperbolic heat conduction equation is solved by the flux-splitting method, and the radiative transfer equation is solved by the discrete ordinate method. The transient temperature response obtained from hyperbolic heat conduction equation is compared with those obtained from the classical parabolic heat conduction equation. The results show that the non-Fourier effect can be important when the conduction-to-radiation parameter and the thermal relaxation time of heat conduction are larger. Under this condition, for the laser-flash measurement of the thermal diffusivity in semitransparent materials, omitting the non-Fourier effect can result in significant errors.

The transient thermal responses in a two-dimensional semitransparent cylinder with black boundary surfaces caused by a pulse irradiation at one end of the cylinder are studied. The processes of the transient coupled radiative-conductive heat transfer in the cylinder are analyzed numerically. An implicit central-difference scheme is employed for handling the energy equation, while a discrete-ordinates method is used to solve the radiative transfer equation. The effects of various parameters on the transient thermal responses are investigated. It is found that, due to the radiation within medium, the transient temperature of the nonirradiated end surface of the cylinder can be greater than that of the inner medium of cylinder. Temperature evolution curves with two peaks can be observed under some conditions at the nonirradiated end of the cylinder. The effects of the conduction-radiation parameter, the optical thickness and refractive index on the transient temperature responses are large. The effects of single-scattering albedo are more significant for the radiation-dominated case than that for the conduction-dominated case.

A radiative transfer model for a linearly or nonlinearly anisotropic scattering medium is developed by the ray tracing method. Under specular reflection, the radiative transfer coefficients of absorbing and anisotropic scattering layer with opaque boundaries are deduced. Coupled radiative and conductive heat transfer is solved. The advantage of the method is that it only needs to disperse spatial position, but not solid angle. A comparison of the present results with the previous results shows that the radiative transfer coefficients of an anisotropic scattering slab are correct. The influence of optical thickness, surface emissivity, spectrum characteristics, albedo, and boundary conditions on the transient temperature and the heat flux distribution are analyzed. According to analyzed results of linear scattering and nonlinear scattering, it is found that the ratio of two-dimensionless heat fluxes with two different scattering phase functions is a monotone function of optical thickness. It can be used as a benchmark to verify the results.

The internal distribution of radiative absorption in one-dimensional semitransparent slab exposed to collimated irradiation is determined by the ray tracing method, and the detailed computation formulae for the distribution of radiative absorption are deduced. It is found that the ray will be polarized by specular reflection of slab boundaries even if the collimated irradiation is unpolarized, and the extent of polarization increases with the internal reflection times. The effects of polarization on the radiative absorption are analyzed and the radiative absorption distributions are compared with those obtained from the case in which the effects of polarization are omitted. The results show that the large differences between re6ectances of perpendicular and parallel polarized components are the main causes resulting in errors of radiative absorption distribution. The polarization of incident beam has significant influences on the radiative absorption. Even for an unpolarized beam irradiated near Brewster's angle, omitting the effects of polarization will result in large errors, and the errors increase with the refractive index.