Optimizing thermal management of convective heat transfer in a complex nanofluid-filled cavity using the lattice Boltzmann method

Purpose This study aims to optimize natural convective heat transfer in a complex cavity filled with Al2O3/water nanofluid. It compares theoretical and experimental nanofluid models, focusing on thermal conductivity and viscosity. In addition, it explores the optimal configuration of a rectangular heater, analyzing its aspect ratio, orientation and position. Design/methodology/approach The lattice Boltzmann method was used to simulate natural convection in a complex cavity with a partially heated left wall, a cooled right wall and other walls are adiabatic. Simulations are conducted for 15 heater configurations, varying Rayleigh numbers (103 ≤ Ra ≤ 106), and compared theoretical (M I) and experimental (M II) nanofluid models, with results presented through isotherms, streamlines, velocity and temperature profiles and Nusselt numbers. Findings The results indicate that the geometric design of the heater plays a crucial role in optimizing thermal performance and fluid dynamics. The optimal configuration occurs when the heater is horizontally oriented and placed at the cavity’s bottom, maximizing heat transfer and fluid circulation. The choice of nanofluid model significantly impacts the balance between thermal conductivity and viscosity. M I enhances thermal conductivity with minimal viscosity variation, while M II shows increased viscosity sensitivity. Originality/value This study offers an in-depth analysis of the interaction between geometric heater design, nanofluid models and heat transfer optimization in a complex cavity. It contributes significantly to thermal performance optimization in applications like electronic devices and energy systems. The comparison of multiple heater configurations and the evaluation of theoretical and experimental nanofluid models offer novel insights, reinforcing the originality of this research.