Heat conduction in dielectric solids is almost entirely due to atomic motions being transferred by lattice waves. In a porous material, a time lag between measured temperature responses and analytical temperature responses which are obtained from Fourier's heat conduction equation under the assumption of the local equilibrium, is observed. From this fact, some researchers claims that the heat conduction in the porous material behaves like a wave and temperature responses are governed by Cattaneo and Vernotte equation rather than Fourier's heat conduction equation for entire period. In order to examine this fact, experiments on the transient heat conduction in glass bead beds are conducted. The glass bead bed is heated from both side walls and the temperature responses are measured by thermocouples. The glass beads of 0.04, 0.1 and 1 mm in diameters are tested. Numerical analysis using Fourier's equation under the assumption of the non equilibrium between the solid and gas phases, are conducted. The results show that the time lag becomes shorter with decreasing the glass bead diameter. The analytical temperature responses are qualitatively coincide with the measured temperature responses.
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