Convection of Cu-water nanofluid in a vented T-shaped cavity in the presence of magnetic field

This paper presents the results of a numerical study on the mixed convection of Cu-water nanofluid in a T-shaped cavity in the presence of a uniform magnetic field. Some sections of the bottom walls of the cavity are heated at a constant temperature and the other walls are thermally insulated. The nanofluid at a relatively low temperature enters from the bottom and exits from the top of the cavity. The governing equations are solved numerically with a finite volume approach using the SIMPLE algorithm. The effects of parameters such as Reynolds number (10 ≤ Re ≤ 400), Richardson number (0.01 ≤ Ri ≤ 10), Hartmann number (0 ≤ Ha ≤ 80), solid volume fraction (0 ≤ φ ≤ 0.06), and cavity aspect ratio (0.1 ≤ AR ≤ 0.4) on the fluid flow and the thermal performance of the cavity are studied. The results indicate that the presence of nanoparticles enhances the heat transfer except at Re = 100 and Ha < 10 as well as Re = 400 and Ha < 60, where pure water has a slightly higher heat transfer rate compared to the nanofluid. The influence of nanofluid on the heat transfer enhancement increases as AR increases. For Ri = 0.01 and 1, the maximum heat transfer rate is obtained at AR = 0.4; however, for Ri = 10, the maximum heat transfer rate occurs at AR = 0.1.