Thermal conductivity of nanofluids
As mentioned before, nanofluids exhibit superior heat transfer characteristics to conventional heat transfer fluids. One of the reasons is that the suspended particles remarkably increase thermal conductivity of nanofluids. The thermal conductivity of nanofluid is strongly dependent on the nanoparticle volume fraction. So far it has been an unsolved problem to develop a sophisticated theory to predict thermal conductivity of nanofluids, although there exists some semi-empirical correlation to calculate the apparent conductivity of two-phase mixture. On the basis of the following definition of the effective thermal conductivity for a two-component mixture