IMPORTANCE OF THERMAL CONDUCTIVITY MODELS IN ANALYZING HEAT TRANSFER OF RADIATIVE HYBRID NANOFLUID ACROSS A STRETCHING SHEET USING DARCY-FORCHHEIMER FLOW

Abstract

Hybrid nanofluids' enhanced thermal efficiency has important applications in many fields of industry and engineering. The goal of this study is to find out how different thermal conductivity models affect important factors in the Darcy-Forchheimer flow and heat transfer of a hybrid nanofluid made of Al₂O₃ - Cu and water across a moving surface that can let some fluid pass through it. Magnetohydrodynamics (MHD), thermal radiation, joule heating, and viscous dissipation are all included in the study. Partial differential equations (PDEs) are made more manageable by reducing them to a set of ordinary differential equations (ODEs) via a similarity transformation. After that, Mathematica’s shooting technique and the Runge-Kutta algorithm are used to numerically solve these ODEs. The study analyzes the effects of key factors on the major physical quantities of interest and presents the findings graphically and tabularly. The research also shows that differing thermal conductivity models lead to significantly varied average Nusselt values. The rate of heat transmission improves with the addition of (φ₂ and S. The Xue model in the hybrid nanofluid shows a 0.7% increase in heat transfer rate compared to the nanofluid, while the Maxwell model shows a 0.64% increase and the Yamada-Ota model shows a 1.01% increase. Importantly, for all the considered models of thermal conductivity, the research shows that the average Nusselt number increases linearly with the nanoparticle volume percentage. Finally, the data shows that the Yamada-Ota model consistently produces far higher average Nusselt values than the other models.