Impact of colloidal properties of cupric oxide-water nanofluid on cooling of miniaturized systems: a numerical and experimental investigation

Nanofluids are engineered materials which are basically colloidal substances prepared by the dispersion of metallic/metallic oxide nanoparticles into a suitable base fluid. The two different phases in nanofluids (solid and liquid) result in entirely different thermophysical properties from the separated phases. The properties exhibited by nanofluids have inspired the researchers to analyze them under a variety of backgrounds. The effectiveness of CuO/water nanofluids in cooling of a smartphone processor is investigated and compared to water in this work. The cross-sectional area for heat dissipation from a processor is obtained from its datasheet. In the first step, numerical analysis is done with water as the medium of heat transfer with a heat flux, and then, experiment is performed using CuO/water nanofluid as heat transfer medium for four volume fractions 0.1%, 0.2%, 0.3% and 0.4% and fluid gap thicknesses as done in the case of water. The heat transfer through nanofluid will be effective only if both the base fluid and nanofluid are in the same mode of heat transfer—either conduction or convection. The mode of heat transfer depends on a number of factors such as temperature, fluid layer thickness, nanoparticle volume fraction, etc. A numerical and experimental investigation on the impact of these parameters is done in this paper using cupric oxide–water nanofluid. It is concluded that the advantage obtained by the increased thermal conductivity of the nanofluid due to the addition of nanoparticles will be offset by the delayed convection onset resulting in a reduced overall heat transfer enhancement when compared to base fluid. Since the convection process is aided by increased temperature, a nanofluid is suitable for enhanced heat transfer under conditions of high heat flux densities and for miniaturized systems where cooling system space is a significant limitation.