ABSTRACT
Recent studies have showed that nanofluids have significantly greater thermal conductivity compared to their base fluids. Large surface-area-to-volume ratio and certain effects of Brownian motion of nanoparticles are believed to be the main factors for the significant increase in the thermal conductivity of nanofluids. This chapter evaluates all three transport properties, namely, thermal conductivity, electrical conductivity, and viscosity, for alumina nanofluid (aluminum oxide nanoparticles in water). Hamilton and Crosser developed an elaborate model for the effective thermal conductivity of two-component mixtures as a function of the conductivity of the pure materials, the composition mixture, and the shape of the dispersed particles. Jang and Choi described the role of Brownian motion in the enhanced thermal conductivity of a nanofluid. Prasher described three possible mechanisms for thermal energy transfer in nanofluids: translational Brownian motion, existence of an interparticle potential, and convection in the liquid due to the Brownian movement of the particles.
