The Effects of Thermophoresis and Brownian Motion on the Flow of a Nanofluid in Rectangular Channels Using Buongiorno’s Model

Abstract

Nanofluids is an emerging sector of working fluids that promise to enhance heat transfer by increasing fluids’ thermal conductivity by inputting metal nanoparticles into a base fluid. There are two ways of modelling nanofluids; single-phase and two-phase. Since nanoparticle sedimentation may influence heat extraction, the Buongiorno two-phase model will be of focus to understand Brownian motion as well as thermophoretic effects on nanofluids. This research presents the case of investigating the thermal performance of plain water, as well as Al 2 -3ater and TiO -2ater nanofluids with varying concentrations and flow rates in rectangular channelled configurations. The results revealed that the Nusselt number and thermal efficiency index augmented by increasing the Reynolds number and nanoparticle concentrations. Furthermore, higher Reynolds numbers and nanoparticle concentrations increased homogeneity in nanoparticle distributions. Lastly, 2 and 3-channel configurations were utilized in the study, the 2-channel model yielded symmetrical flow allowing uniform nanoparticle distributions, leading to higher thermal efficiencies.