Nanofluid natural convection of hot concentric cylinder in oval-shaped porous cavity at different eccentricity.

Purpose: This paper aims to study the effect of concentric hot circular cylinder inside egg-cavity porous-copper nanofluid on natural convection phenomena. Design/methodology/approach: The finite element method–based Galerkin approach is applied to solve numerically the set of governing equations with appropriate boundary conditions. Findings: The effects of different range parameters, such as Darcy number (10–3 = Da = 10–1), Rayleigh number (103 = Ra = 106), nanoparticle volume fraction (0 = ϑ = 0.06) and eccentricity (−0.3 = e = 0.1) on the fluid flow represent by stream function and heat transfer represent by temperature distribution, local and average Nusselt numbers. Research limitations/implications: A comparison between oval shape and concentric circular concentric cylinder was investigated. Originality/value: In the current numerical study, heat transfer by natural convection was identified inside the new design of egg-shaped cavity as a result of the presence of a circular inside it supported by a porous medium filled with a nanofluid. After reviewing previous studies and considering the importance of heat transfer by free convection inside tubes for many applications, to the best of the authors' knowledge, the current work is the first study that deals with a study and comparison between the common shape (concentric circular tubes) and the new shape (egg-shaped cavity). [ABSTRACT FROM AUTHOR]