Determination of nanolayer thickness for a nanofluid

Recent core–shell–medium models as a modification of the traditional effective medium theories for explaining the enhanced thermal conductivity of nanofluids are semi-empirical. Generally, the resulting thickness and conductivity of the nanolayer both have to be chosen to match the measured thermal conductivity of the nanofluid. Here, we attempt to find a more systematic procedure to determine the nanolayer thickness and the thermal conductivity profile within the nanolayer. An expression for the nanolayer thickness is derived by manipulation of the three basic heat conduction regions. Comparison of the estimated thermal conductance with known experimental data and thermal diffusion length are made.