Numerical Study of Mixed Convection Heat Transfer of a Nanofluid in an Eccentric Annulus

Abstract

This article deals with a numerical study of mixed convection flow and heat transfer of Al₂O₃-water nanofluid inside an eccentric horizontal annulus with rotation on the inner cylinder. The inner and outer cylinders are kept at different constant temperatures as T_h and T _c , respectively. First, the governing dimensional equations in terms of stream function-vorticity formulation in polar coordinate system for eccentric physical domain are transformed in dimensionless form. These equations are then transformed to a rectangular domain in order to get better accuracy of the solution near the boundaries. The resultant equations are further discretized with a finite volume technique based on a second order upwind scheme and then solved by iteration. The effects of the eccentricity ϵ, Reynolds number Re, the nanoparticles volume fraction parameter φ, the Rayleigh number Ra on the mean Nusselt number Nu, and the streamlines and isotherms are investigated. The results are also discussed in detail. It is found that a very good agreement exists between the present results and those from the open literature.