Entropy generation analysis of hybrid-nanofluid during natural convection through two coaxial cylinders partially filled with porous medium under magnetic field

Document Type : Article

Authors

Research laboratory in physics and sciences for engineering, LRPSI Sultan Moulay Slimane university, Polydisciplinary faculty, Beni Mellal, 23000, Morocco

Abstract

The aim of this research is to analyze the magneohydrodynamic heat transmission in an
annular space partially porous between two coaxial cylinders with a permeable interface saturated by a hybrid nanofluid (water-Cu/Al2O3) and study the entropy generation to better
understand the heat transfer processes. The inner and outer cylinders are kept at a constant
hot and cold temperature. The base walls are designed to be impermeable and insulated. A
finite difference-based vorticity-stream function is used to solve the nonlinear coupled conservation equations using Successive Over Relaxation approach. The obtained numerical outcomes
in terms of streamlines, isotherms, Nusselt and Bejan numbers, and entropy generation are presented to demonstrate the effect of various control parameters. The findings of this numerical
simulation show that the increase in the Ra number improves the thermal energy transmission
across the active wall. Further, a rise in nanoparticle concentration causes a rise in thermal conductivity, which contributes to enhancing the heat transfer rate. In addition, the mean entropy
generation elements rise with increasing Rayleigh number, Darcy number, and nanoparticle
concentration; however, with the exception of magnetic irreversibility, the reverse development
is detected. Furthermore, the Bejan number is reduced in order to increase the Rayleigh and
Darcy numbers.

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