The effect of the baffle length on the natural convection in an enclosure filled with different nanofluids

This paper presents a numerical investigation of the natural convection in an inclined rectangular enclosure with a baffle filled with Cu/water and then with Al₂O₃/water nanofluids using the finite difference method for tracking the thermal behavior within it versus the baffle length. The horizontal enclosure walls are assumed to be adiabatic, while the vertical ones are supposed to be a differentially heated. A thin horizontal baffle was attached to its left sidewall and is assumed to be cold. The flow and thermal fields are computed, respectively, for various values of Rayleigh number (10³ ≤ Ra ≤ 10⁵), inclination angle (0° ≤ ∅ ≤ 60°), baffle length (0.25 ≤ L_b ≤ 0.5), solid volume fraction (0.02 ≤ ϕ ≤ 0.06), and aspect ratio (1 ≤ AR ≤ 2). It was found that as the Rayleigh number, solid volume fraction, baffle length, and aspect ratio increase, an enhancement in the intensity of fluid flow in the enclosure was observed. In comparison, it reduces when the inclination angle increases. Moreover, it was found that the local Nusselt number (Nu_c) enhances with the rise in Rayleigh number and the solid volume fraction. In contrast, it reduces with the increase in the aspect ratio and the inclination angle.