Heat diffusion in two-layer structures: Photoacoustic experiments

The effective thermal conductivity and thermal diffusivity of a two-layer system are investigated from the theoretical point of view for application to photoacoustic experiments. The effective thermal parameters are obtained by comparing the temperature distribution on the left or right surface of the layered structure and some effective one-layer material. These effective thermal parameters are calculated for some special cases as for example, low and high chopper frequency. The influence of the interface thermal contact between the layers plays an important role on the effective thermal parameters. It is shown that the effective thermal conductivity and thermal diffusivity depend strongly upon the used photothermal technique.