Effect of a magnetic field on natural convection in an open cavity subjugated to water/alumina nanofluid using Lattice Boltzmann method

In this paper, the effect of a magnetic field on natural convection in an open enclosure which subjugated to water/alumina nanofluid using Lattice Boltzmann method has been investigated. The cavity is filled with water and nanoparticles of Al2O3at the presence of a magnetic field. Calculations were performed for Rayleigh numbers (Ra=104-106), volume fractions of nanoparticles (φ=0,0.02,0.04 and 0.06) and Hartmann number (0≤Ha≤90) with interval 30 while the magnetic field is considered horizontally. Results show that the heat transfer decreases by the increment of Hartmann number for various Rayleigh numbers and volume fractions. The magnetic field augments the effect of nanoparticles at Rayleigh number of Ra=106regularly. Just as the most effect of nanoparticles for Ra=104is observed at Ha=30, so the most influence of nanoparticles occurs at Ha=60 for Ra=105. © 2012 Elsevier Ltd.