Empirical correlation finding the role of temperature and particle size for nanofluid (Al2O3) thermal conductivity enhancement -: art. no. 153107

In this letter, we report an experimental correlation [Eqs. (1a d1b) or (1c)] for the thermal conductivity of Al2O3 nanofluids as a function of nanoparticle size (ranging from 11 nm to 150 nm nominal diameters) over a wide range of temperature (from 21 to 71 degrees C). Following the previously proposed conjecture from the theoretical point-of-view (Jang and Choi, 2004), it is experimentally validated that the Brownian motion of nanoparticles constitutes a key mechanism of the thermal conductivity enhancement with increasing temperature and decreasing nanoparticle sizes. (C) 2005 American Institute of Physics.