Natural convective Cu-water nanofluid flow in isosceles triangular cavity with forced free stream cooled sides and localized heated base

The present paper aims to conduct a numerical investigation of the natural convective flow of Cu-water nanofluid in an isosceles triangular-shaped cavity, where an air stream cools the lateral walls while its base is subjected to discrete heating. The governing equations are numerically solved using the finite volume method (FVM) employing ANSYS FLUENT. The results are presented with diverse scopes of pertinent parameters, including non-dimensional heater length (L/H = 0.25, 0.5, and 1), Rayleigh Number (Ra = 104, 105, and 106), nanoparticles volume fraction (φ = 0, 0.03, 0.06 and 0.09), and free stream Reynolds number (Re∞ = 102, 103, 104 and 105). The impact of each of these parameters is depicted on the isotherms (θ) lines, stream function (ψ) contours, and the average Nusselt number (Nuavg) plots on the heated lower wall. The findings showed the subsequent enlargements in Nuavg with an increase in Ra by 515 %, L/H by 130 %, Re∞ by 43 %, and φ by 137 %, indicating an enhancement in the heat transfer rate with these parameters. Besides, extra secondary eddies will be generated inside the cavity when Ra becomes more extensive, while the flow configuration is not influenced by the enlargement of φ, Re∞, and L/H. The present model findings have been compared with other work from the literature and showed an acceptable agreement with a maximum error of less than 1 %.