Three-dimensional mixed convection and entropy generation of binary and ternary hybrid nanofluids flow inside a porous media-filled horizontal annular duct under magnetic field

Abstract

In the present investigation, computational study of magneto-laminar flow mixed convection and entropy generation using two binary (TiO2-CNT/kerosene), (TiO2-Gr/kerosene) and ternary hybrid (TiO2-CNT-Gr/kerosene) nanofluids inside three‐dimensional horizontal annular duct saturated with porous media are numerically investigated. The exterior cylinder’s surface is uniformly heated through a uniform heat flux, whereas the interior cylinder’s surface is adiabatic. The numerical solutions are obtained using the finite volume method (FVM). The single-phase and thermal equilibrium models are adopted. The control parameters are: Darcy number (10−4 ≤ Da ≤ 10−1), Hartmann number (0 ≤ Ha ≤ 50), magnetic field inclination (ψ = 0°, ψ = 90°), Grashof number (Gr = 106), and nanoparticle concentrations 5%. The study of hydrodynamic and thermal behavior reveals that significant improvements in heat transfer are obtained when a magnetic field is applied horizontally and in the same direction as the flow. At the same time, it involves retardation on the hybrid nanofluids flow. Moreover, when the Darcy number increases, the heat transfer rate reduces by 24%, 23%, and 21% for TiO2-CNT-graphene/kerosene, TiO2-CNT/kerosene, and TiO2-Graphene/kerosene, respectively. No significant influence was observed on heat transfer when the applied magnetic field was perpendicular to the flow direction and in the same direction as the buoyancy force.