RESEARCH ARTICLE Computational fluid dynamic evaluation of heat transfer enhancement in microchannel solar collectors sustained by alumina nanofluid Amirhossein Ahadi 1 | Sylvie Antoun 1 | M. Ziad Saghir 1 | John Swift 2 1 Department of Mechanical and Industrial Engineering, School of Engineering, Ryerson University, Toronto, Ontario, Canada 2 Solar Tomorrow Inc. Research and Development, Toronto, Ontario, Canada Correspondence M. Ziad Saghir, Department of Mechanical & Industrial Engineering, 350 Victoria St, Toronto, ON, Canada M5B 2K3. Email: zsaghir@ryerson.ca Abstract Nanofluids have produced a wide range of researches for various cooling/heating purposes, owing to the enhanced thermophysical properties they bring by suspending nanoparticles in the base fluid. This work proposes a detailed com- putational fluid dynamic (CFD) study of heat transfer enhancement in micro- channel solar collectors coupled with nanofluid. The accuracy of the numerical model is ensured through a reliable finite element analysis considering the complexity of the three-dimensional structure of microchannel solar collector. The thermophoretic motion induced by the suspension of Al 2 O 3 nanoparticles was also evaluated to further understand the thermal enhancement observed in forced convection regimes. The accuracy of the model was first validated with respect to propylene glycol/water fluid, and then applied to evaluate the perfor- mance for Al 2 O 3 /water nanofluid. A detailed comparison of the performance of the two fluids with an assessment of the temperature and velocity profiles, was adopted to evaluate the thermal efficacy of adding nanofluids. A further inves- tigation of the effect of solar collector inclination angles (0, π/6, π/4,and π/3) at the optimal volumetric concentration of the nanofluid was also done to determine the impact of the system geometry on the efficacy of the heat removal. It was established that the optimal heat removal is achieved at 2% nanoparticle concentration. Finally, it was also detected that increasing the inclination angle of the solar collector (from 0 to π/3) obstructed the heat removal efficiency. KEYWORDS finite element simulation, heat transfer enhancement, propylene glycol/water mixture, solar thermal collector, Al 2 O 3 /water nanofluid 1 | INTRODUCTION Solar Tomorrow, Inc carries out the design and distribution of solar thermal collectors to produce hot water, space heating, and space cooling. Their technology employs a unique Solar Rating & Certification Corporation (SRCC) The Novelty Statement—This article presents some uniqueness in differ- ent aspects: (a) a detailed three-dimensional numerical modeling of a solar collector using nanofluid as circulating liquid; (b) a special design of the collector internal channels with fins aiming at enhancing the heat extraction; (c) comparison of current results with some available experi- mental data; (d) investigation of the effect of solar collector inclination angle at the optimal volumetric concentration of nanofluid. Received: 16 December 2018 Revised: 19 January 2019 Accepted: 21 January 2019 DOI: 10.1002/est2.37 Energy Storage. 2019;1:e37. wileyonlinelibrary.com/journal/est2 © 2019 John Wiley & Sons, Ltd. 1 of 13 https://doi.org/10.1002/est2.37