LBM Simulation of Free Convection Heat Transfer of Cu/Water Nanofluid in Inclined Cavity with Non-Uniform Heating Temperature Distribution

Abstract

In the present study, natural convection of Cu/water nanofluid in an inclined square cavity has been investigated numerically using lattice Boltzmann method (LBM). The left wall of the cavity is maintained at a constant hot temperature, while the right wall is subjected to non-uniform temperature distribution. The upper and lower walls are insulated. The fluid flow and heat transfer characteristics are investigated over a wide range of parameters, including Rayleigh numbers (Ra = 103, 104 and 105), solid volume fractions (Φ = 0%, 2%, 4% and 6%), amplitude ratio (A = 0, 0.5 and 1) and phase deviations of sinusoidal temperature distribution (Φ = 0, π/4, π/2, 3π/4 and π). The results are presented graphically in the form of streamlines, isotherms and Nusselt numbers for the different combinations of the considered parameters. The heat transfer rate inside the nanofluid increases as the Rayleigh number and the volume fraction of nanoparticles increase. Further, an increase in the amplitude ratio results in a decrease in the heat transfer rate, with a reduction of up to 8.67% at A = 1. On the other hand, changes in the phase deviation of the sinusoidal temperature distribution lead to an increase in the heat transfer rate, with a surge of up to 32.04% observed at Φ = π.