Lattice Boltzmann Method Simulations of Laminar Mixed Convection in an Inclined Lid-Driven Cavity Discretely Heated and Filled with Nanofluid

Abstract

The mixed convection of fluid flow and heat transfer in a discretely heated square lid-driven cavity has been numerically investigated using the lattice Boltzmann method. The fluid inside the inclined cavity is a water-based nanofluid, enhanced with Al₂O₃ nanoparticles. The cavity is discretely heated from the left and bottom walls and cooled from the right wall, while the top wall is adiabatic and moves at a constant velocity. Simulations have been performed to analyze the effects of key controlling parameters, including the Richardson number (Ri), inclination angle (θ), and the solid volume fraction of nanoparticles (ϕ). The results indicate that increasing the inclination angle enhances heat transfer on the left wall but reduces it on the bottom wall. Furthermore, to achieve the lowest mean fluid temperature, an inclination angle of 90° is recommended, regardless of the Richardson number and nanoparticle volume fraction. Additionally, the introduction of nanoparticles into the base fluid improves the heat transfer rate and increases the average temperature within the cavity. Nomenclature