Entropy Generation Analysis of Non-Newtonian Nanofluid Flow in Asymmetrically Heated Microchannels

This study aims to investigate heat transfer and entropy generation for a non-Newtonian power-law fluid in an asymmetrically heated parallel plate channel. By employing the stress and straining rate relationship for a power-law fluid, and accounting for viscous dissipation, this work presents an analytical model that integrates the effects of power-law rheology, and asymmetrical heating conditions, yielding expeditious closed-form temperature and Nu expression. The heat transfer and entropy generation are elucidated for the internal forced convection of a shear-thinning hybrid nanofluid, specifically, multiwalled carbon nanotubes [Formula: see text], with known rheological behavior in the literature, in an asymmetrically heated microchannel for a Reynolds number, [Formula: see text]. Comparative assessments with the Newtonian base fluid, EG–water (50–50 vol %) highlight up to a 16% and 70% hike in heat transfer coefficients and performance evaluation criterion respectively of the hybrid nanofluids, of 1 vol %, and 2 vol %, [Formula: see text], and the dominance of heat transfer irreversibility over fluid flow irreversibility in the entropy generation, resulting in up to a 189% surge in the average Bejan number. By evaluating the Nusselt number and entropy generation within a shear-thinning hybrid nanofluid under asymmetrical heating, the study relates analytically the rheology, viscous dissipation, cooling performance, and irreversibility analysis that is lacking in many prior works.