Heat and mass transfer analysis of non-Newtonian power-law nanofluid confined within annulus enclosure using Darcy-Brinkman-Forchheimer model

Non-Newtonian fluids are encountered in many engineering applications, such as the petroleum industry and lubrication. In this investigation, the Magnetohydrodynamic (MHD) and convective boundary (heater) are assumed to analyze the heat transport phenomena of non-Newtonian type Carboxy-Methyl-Cellulose (CMC)/Aluminum oxide (Al2O3) hybrid nanofluid in an annulus enclosure. A porous medium saturates the enclosure under the privileges of Darcy-Brinkman law. Galerkin Finite Element Method (GFEM) is employed for numerical findings. Power-law type non-Newtonian-nanofluid is investigated for different volume fractions (φ) in an aqueous solution of CMC. The flow and the thermal behavior of the nanofluid are investigated for dissimilar values of Rayleigh (Ra), Hartman (Ha), and Darcy (Da) numbers and power-law index (n). The average Nusselt (Nuavg) and Bejan (Beavg) numbers were evaluated for the nanofluid flow. The results indicate that the present composition of nanofluid enhances the heat transfer inside the enclosure. This effect can be further improved by increasing Ra and Da numbers or decreasing the power-law index or magnetic forces. The Da number and power-law index are excellent control parameters for entropy generation. Overall, these results offer a good lead into the design and optimization of thermal performance within an annulus enclosure inundated by a Darcy medium. On the other hand, the outcomes also indicate that, at Ra = 1000, owing to the limited drive of fluid flow inside the cavity, the conduction heat flux is predominant, and the upsurge of the parameter n hasn't a significant effect on Nuavg variations. At the highest Ra, increasing n, and Ha, reduced Nuavg by 50% and 40%, respectively. While increasing, Da improved Nuavg by 245%