Nanofluid - A new concept in heat transfer and thermal management

Nanofluids are quasi-single phase heat transfer fluids with negligible (< 1 vol. %) amount of nanometric solid dispersion in a base fluid making a stable colloidal suspension. These fluids are of interest due to the extraordinary (40-200%) enhancement of thermal conductivity possible that eludes a precise scientific explanation as yet. In the present paper, some interesting results pertaining to the synthesis and characterization of nanometric Al-alloy particle dispersed water and ethylene glycol based nanofluids have been presented after a brief overview of the evolution of the concept of nanofluid. While the nanofluid is prepared by a two-stage process including mechano-chemical synthesis of nanocrystalline Al70Cu30 alloys powders, thermal conductivity is measured using an improvised thermal comparator method. The results indicate that the thermal conductivity ratio could be enhanced up to 100% with a dispersion of only 2 vol.% nanometric Al alloy particles in water or ethylene glycol.