Mesoscopic study of natural convection in a square cavity filled with alumina-based nanofluid

摘要

In this work, the two-dimensional natural convection flow in a square cavity, with the vertical walls at slightly different temperatures and the horizontal boundaries taken as adiabatic has been investigated numerically by the thermal lattice Boltzmann method with the double population approach. The study was carried out for a homogeneous nanofluid containing pure water Pr=6.2 and alumina nanoparticles for solid volume fractions: Φ = 0.02, 0.04, 0.06 and 0.08 in laminar regime. The single-phase model was adopted; the effective dynamic viscosity and thermal conductivity were respectively evaluated by Brinkman and Maxwell-Garnetts models. Results are presented in terms of: streamlines, isotherms, Nusselt number, velocity and temperature profiles. According to this study, the heat transfer rate increases with the increase of Rayleigh number and solid volume fraction.