A report on the latest trends in nanofluid research

The term Nanofluids was first coined by Sir Stephen Choi in 1995 at Argonne National Laboratory ,U.S.A .Since the discovery, nanofluid have been explored as heat transfer fluids. Nanofluids increased the thermal conductivity of existing coolants (Water, Ethylene glycol) by a magnitude of hundred times which made them attractive for miniaturization of electronic devices .From 1995 till 2008 nanofluid research was focused on enhancing the thermal conductivity of the base fluid by various parameters like shape of nanoparticle, volume fraction of base fluid and material of base fluid and composition of nanoparticle. A lot of theoretical models have been evolved in an attempt to explain the basic mechanism of heat transfer in a nanofluid .Research has been with respect to viscosity, stability, thermal conductivity and convective heat transfer coefficients of nanofluids. From 2008 nanofluids have been investigated for their electrical properties and reported as electrical conductivity enhancers for base fluid. The latest trend in nanofluid is towards optical properties of nanofluid for direct absorption solar collectors.