Effect of Wavy Interface on Natural Convection in Square Cavity Partially Filled with Nanofluid and Porous Medium using Buongiorno Model

Abstract

nvective heat transfer improvement from wavy surfaces presents a new solution in industrial engineering for composite materials, including porous medium, and nanofluids to address the wavy irregular surfaces in heat transfer devices such as a wavy solar collector, energy absorption and filtration, thermal insulation, and geothermal power plants. This technique enables the performance of engineering applications. The numerical study is performed to examine the effects of a wavy interface separating two layers in the enclosure on heat exchange rates. This paper investigates numerically the natural convection flow in a square cavity partially filled with nanofluid-porous layers separated by a wavy horizontal interface. The left and right walls of the cavity are maintained at constant hot and cold temperatures, whereas the other walls are adiabatic. The Buongiorno model is used to describe nanofluid motion, taking into account the brownian and thermophoresis effects in the cavity. The Galerkin finite element method was applied to solve the differential governing equations. The dynamic, thermal field and heat transfer have been analyzed for various parameters such as Rayleigh number (10^3 ≤ Ra ≤ 10^6), the amplitude of interface (0 ≤ A ≤ 0.1), and undulation number (0 ≤ n ≤ 9). The results reveal that the flow intensity induced by buoyancy forces is more significant in the nanofluid layer than in the porous layer, since the heat transfer is enhanced while the flow is not sensitive to variations in amplitude and number undulation, and accordingly, the decline of average Nusselt and Sherwood numbers is insignificant. The effects of controlled parameters on the structure of nanofluid flow, heat, and mass transfer rate are insignificant.