Forced Convection in Porous Media Using Al2O3 and TiO2 Nanofluids in Differing Base Fluids

M Z Saghir,C Welsford

doi:10.3390/en13102665

Abstract

The following work presents a numerical evaluation of the use of TiO2 and Al2O3 nanofluids operating with ethylene glycol and water as base fluids—as well as an experimental evaluation of Al2O3-water nanofluid. Both numerical and experimental systems were tested and operated under various flow and heat transfer conditions, including four flow rates and three heat fluxes. When compared, the numerical schemes and experimental results showed deviation of under two degrees Celsius. This led the authors to conclude that the numerical scheme accurately reflected the experimental conditions. When all combinations of mixtures were compared numerically, it was found that ethylene glycol provided the highest average Nusselt number, while water offered significantly lower pumping requirements. When comparing nanoparticles, it was found that, in a carrying-fluid of water, TiO2 had superior performance by approximately one percent.

Highlights

Nanofluids are a class of fluid composed of liquids used as base fluids, mixed with a set quantity of nanoparticles
A numerical model is used to investigate the performance of TiO2 nanofluid against an Al2 O3 nanofluid
In the entire text the concentration of nanoparticle is set equal to 0.5% vol The Al2 O3 nanofluid mixture did not contain any surfactant and precipitation was not detected one month after preparing the solution in the lab

Summary

Introduction

Nanofluids are a class of fluid composed of liquids used as base fluids, mixed with a set quantity of nanoparticles. These nanoparticles have differing physical properties from that of the base fluid aiming at enhancing the rate of heat removal. The concentration of the nanoparticles may be varied from 0.1% to up to 4%. A large number of researchers have exaggerated the performance of this class of fluid. The focus is first on conducting experiments to assess the importance of Al2 O3 nanofluids and to determine the validity of the numerical model. A numerical model is used to investigate the performance of TiO2 nanofluid against an Al2 O3 nanofluid

Methods

Results

Conclusion