A Single-Component Nonhomogeneous Lattice Boltzmann Model for Natural Convection in Al₂O₃/Water Nanofluid

Abstract

Natural convection heat transfer in Al₂O₃/water nanofluid is analyzed using the single-component nonhomogeneous lattice Boltzmann method (SCNHLBM). There exists a contradictory observation between the numerical and experimental works in the literature with respect to the heat transfer of nanofluids in natural convection. Nanofluid is treated as a single component with nonhomogeneous particle distribution introduced by a concentration transport equation of nanoparticles by considering the Brownian and thermophoretic diffusions. The average Nusselt number is found to deteriorate with increasing nanoparticle volume fraction; thus the trend of the experimental results is captured using SCNHLBM. Addition of Brownian and thermophoretic diffusion results in additional thermal diffusion and hence reduces the convective transport of heat. The contribution of Brownian and thermophoretic diffusions in heat transfer deterioration is revealed.

The authors would like to thank P.G. Senapathy Computing Center, IIT Madras, for providing access to VIRGO SUPER CLUSTER for the simulation. The authors would also like to acknowledge the useful technical discussions and inputs on LBM from Dr Martin Geier, during his DAAD-IIT faculty exchange stay at IIT Madras.