ABSTRACT
The investigations on nanofluids reported in the literature can be divided into two types: (1) investigations of thermal conductivity and (2) investigations of heat transfer coefficients. In both cases, the studies have been mainly experimental. However, there were several attempts to develop a model to explain the alleged enhancement of thermal conductivity invoking Brownian motion of nanoparticles [6], agglomeration of nanoparticles increasing heat flux [7], high thermal conductivity of the liquids on the surface of nanoparticles [8], ballistic phonon transport in nanoparticles [9], or near-field radiation [10]. Each of these models was tested against selected experimental data, but none of them have been found to predict all experimental data well.
