Current research and future applications of nano- and ionano-fluids

Abstract

An overview of several important aspects of nanofluids and ionanofluids, their background, as well as key experimental findings on their thermophysical properties is presented in this study. While nanofluids are prepared by dispersing nanoparticles in traditional heat transfer fluids, ionanofluids are engineered by dispersing nanoparticles in ionic liquids only. Some representative results of various thermal features and properties of both fluids are also briefly discussed. Although there are inconsistencies in experimental data from various groups, nanofluids possess significantly higher thermal conductivity, convective heat transfer coefficient and boiling critical heat flux compared to their base fluids and these properties further increase with increase concentration of nanoparticles. On the other hand, based on results from very limited studies ionanofluids are found to show superior thermophysical properties compared to their based ionic liquids. In addition, numerical results on heat transfer areas from a model study indicated that ionanofluids are better heat transfer fluids for heat exchangers or other heat transfer devices than ionic liquids. Future research direction and applications of these novel fluids are also outlined. Review reveals that both nanofluids and ionanofluids show great promises to be used as advanced heat transfer fluids and novel media for many thermal management systems as well as green solvent-based applications.