Open Access

ARTICLE

Lattice Boltzmann Method for Simulation of Nanoparticle Brownian Motion and Magnetic Field Effects on Free Convection in A Nanofluid-filled Open Cavity with Heat Generation/Absorption and Non Uniform Heating on the Left Solid Vertical Wall

Mohamed Ammar Abbassi¹, Bouchmel Mliki¹, Ridha Djebali^1,2

1 UR:Unité de Recherche Matériaux, Energie et Energies Renouvelables (MEER), Faculté des Sciences de Gafsa, B.P.19, Zarroug, Gafsa, 2112, Tunisie.
2 ISLAIB-Université de Jendouba, Av. H. Bourguiba. BP 340, Béja 9000, Tunisie.

Fluid Dynamics & Materials Processing 2017, 13(2), 59-83. https://doi.org/10.3970/fdmp.2017.013.059

Abstract

This article reports a numerical study of nanoparticle Brownian motion and magnetic field effects by natural convection in a nanofluid-filled open cavity with non uniform boundary condition. Lattice Boltzmann Method (LBM) is used to simulate nanofluid flow and heat transfer. The effective thermal conductivity and viscosity of nanofluid are calculated by KKL (Koo-Kleinstreuer-Li) correlation. In this model effect of Brownian motion on the effective thermal conductivity and effective viscosity is considered and examined. Simulations have been carried out for the pertinent parameters in the following ranges: Rayleigh number (Ra=10³−10⁶), Hartmann number (Ha=0-60), nanoparticle volume concentration (Φ=0–0.04) and heat generation or absorption coefficient (q=−10, −5, 0, 5, 10). The numerical results show a decrease in heat transfer with an increase in particle volume fraction. In addition, it is observed that the Brownian motion greatly influences the heat transfer rate depending on the Hartmann number, Rayleigh number and nanoparticle solid volume fraction. Additionally, in the presence of the heat generation or absorption, the Brownian motion effect on heat transfer at Ra=10³ is more pronounced than other Rayleigh numbers and the least effect is observed at Ra= 10⁶.

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