Numerical and experimental investigations on the heat transfer enhancement in corrugated channels using SiO<inf>2</inf>-water nanofluid

Abstract

In this paper, convective heat transfer of SiO<inf>2</inf>-water nanofluid flow in channels with different shapes is numerically and experimentally studied over Reynolds number ranges of 400-4000. Three different channels such as trapezoidal, sinusoidal and straight were fabricated and tested. The SiO<inf>2</inf>-water nanofluid with different volume fractions of 0%, 0.5% and 1.0% were prepared and examined. All physical properties of nanofluid which are required to evaluate the flow and thermal characteristics have been measured. In the numerical aspect of the current work, the governing equations are discretized by using the collocated finite volume method and solved iteratively by using the SIMPLE algorithm. In addition, the low Reynolds number k-ε model of Launder and Sharma is employed to compute the turbulent non-isothermal flow in the present study. The results showed that the average Nusselt number and the heat transfer enhancement increase as the nanoparticles volume fraction increases, however, at the expense of increasing pressure drop. Furthermore, the trapezoidal-corrugated channel has the highest heat transfer enhancement followed by the sinusoidal-corrugated channel and straight channel. The numerical results are compared with the corresponding experimental data, and the results are in a good agreement. © 2015 The Authors. Published by Elsevier Ltd.