Magnetohydrodynamic Darcy-Forchheimer flow of non-Newtonian second-grade hybrid nanofluid bounded by double-revolving disks with variable thermal conductivity: Entropy generation analysis

Abstract

The study of hybrid nanofluid flow bounded by double-revolving disks is crucial due to its significant applications in enhancing heat transfer in various industrial processes, including cooling systems, lubrication technologies, and energy storage systems. This manuscript presents an entropy generation analysis of the magnetohydrodynamic Darcy-Forchheimer flow of a non-Newtonian second-grade hybrid nanofluid between double-revolving disks with variable thermal conductivity. The hybrid nanofluid combines titanium dioxide (TiO2) and cobalt ferrite (CoFe2O4) nanoparticles in a base fluid of engine oil. Appropriate similarity transformations convert the dimensional equations governing the flow phenomena into a non-dimensional form. The resulting non-dimensionalized system of equations is then solved using the homotopy analysis method (HAM), a semi-analytical technique. The results are validated by comparing them with previously published work for a specific case of the present analysis, and they are found to be in very good agreement. A comprehensive parametric analysis is conducted to understand the behavior of flow and heat transfer to various physical parameters involved in the study. It was found that there is an enhanced heat transfer rate at both disks when the Reynolds number and titanium dioxide nanoparticle concentration are higher. It was also found that Bejan number declined with increasing Brinkman number.