Natural convection of nanofluids inside a vertical enclosure in the presence of a uniform magnetic field

The present study is a theoretical investigation of natural convective heat transfer of nanofluids, inside a vertical enclosure, in the presence of a uniform magnetic field. A modified Buongiornoʹs model is employed for the nanofluid, which fully accounts for the effect of nanoparticle migration. The behavior of the nanofluid is investigated for two different nanoparticles in the water-base fluid, namely alumina and titania. It was observed that the nanoparticles move from the heated walls (nanoparticlesʹ depletion) toward the cold wall (nanoparticlesʹ accumulation) and construct a non-uniform nanoparticle distribution. The results also indicate that for smaller nanoparticles, the nanoparticle volume fraction is more uniform and there is no abnormal variation in the heat transfer rate. Moreover, NuB is reduced in the presence of the magnetic field for alumina/water nanofluid; however, for titania/water nanofluid it is vice versa.