Numerical investigation on the forced laminar convection heat transfer of Al 2 O 3 -water nanofluid within a three-dimensional asymmetric heated channel

Purpose: The purpose of this paper is to carry out a numerical investigation to study laminar convection flow of Al 2 O 3 -water nanofluids within a three-dimensional rectangular section channel asymmetrically heated. Design/methodology/approach: A three-dimensional model of the channel is designed and simulated by using Comsol Multiphysics. The finite elements method is used to perform the numerical simulation. A variety of cases are taken into account by considering Reynolds numbers ranging from 250 up to 1,000, concentration between 0 and 6 per cent, particle dimension of 20, 40 and 60 nm and inlet temperature equal to 293.15 and 320 K. A constant heat flux of 1,000 W/m 2 is imposed on the top surface of the channel. Findings: The results demonstrate that nanofluids guarantee improved thermal performances with respect to the base fluid, as shown by the augmented Nusselt number. On the other hand, pressure drop shows a noticeable increase; therefore, an entropy generation analysis is developed to establish optimal conditions for the system under investigation. Originality/value: The originality of this work consists in the analysis of a three-dimensional asymmetric heated channel with nanofluids in laminar convection. The present work would be beneficial to improve the design of devices with particular focus on solar thermal panel.