The work presents a free convective thermal transport phenomenon in a ring-shaped annulus formed between two confocal elliptical surfaces in the presence of Al2O3/water nanofluid. The main aim of the analysis is to examine the variation in thermo-fluidic behavior and heat transfer characteristics of the set-up with the changes of nanoparticle concentration, ϕ, and Rayleigh number, Ra. The set of prevailing equations are solved numerically by means of finite volume-based computations. The analysis is carried out for a range of parametric studies such as Rayleigh numbers, 103 ≤ Ra ≤ 105, and nanoparticle concentration, 0.33% ≤ ϕ ≤ 2%. The results revealed that both flow pattern and heat transfer characteristics get affected, significantly, with the variation of Rayleigh number. Furthermore, it is found that, even though the heat transfer characteristics are influenced with nanoparticle concentration, the flow structure and temperature patterns remain insensitive to the nanofluid volume fraction. With the upsurge in the degree of the flow stratification, it shows that there is an intensification of heat transfer shown in the formation of convective cells. The increasing Rayleigh number also affected the formation of a number of convective cells formed in the annulus.