Numerical study of natural convection in an inclined cavity filled with Al ₂ O ₃ /Cu-H ₂ O nanofluids

Abstract

The lattice Boltzmann method (LBM) was implemented in the present research to assess a numerical investigation of the heat transfer caused by natural convection in a nanofluid-filled inclined square cavity with a sinusoidal distribution of temperatures on a heated chip in the left wall. It has its foundation in the lattice-BGK (Bhatnagar-Gross-Krook) model and the single-relaxation-time approach of the D2Q9 scheme. A discussion is held concerning the impact of different physical variables on thermal transfer efficiency. The purpose of this study is to examine the impacts of four essential parameters: the Rayleigh number, length of the heated chip, volume concentration of the nanofluids, and tilt angle. These variations encompassed ranges of 103 to 106, H/4 to H, 0% to 6%, and 0° to 315°, respectively. The results indicate that an increase in the Rayleigh number leads to a noteworthy improvement in heat transfer, driven by an accelerated fluid flow induced by buoyancy forces. The tilt angle, interacting with the hot wall's position, becomes a crucial factor, significantly influencing heat transfer in specific orientations. The length of the heating chip impacts fluid flow, demonstrating a marked enhancement in heat transfer within the cavity. Importantly, the use of nanoparticles, particularly in the Cu/H2O nanofluid, exhibits a substantial increase in thermal transmission as the nanoparticle volumetric fraction rises. These findings extend beyond heat transfer mechanisms, carrying significant implications for the scientific and technological realms. The validation findings are in good accord with the available research, the results of experiments, and the numerical data.