Effect of chain-like magnetite nanoparticle aggregates on thermal conductivity of magnetic nanofluid in magnetic field

This paper investigated the effect of chain-like magnetic nanoparticles aggregates on the thermal conductivity of magnetic nanofluids (MNFs) in magnetic field via a proposed model of thermal conductivity of MNFs. The anisotropic feature of thermal conductivity ratio was predicted based on the field induced chain-like magnetic nanoparticles aggregates in MNFs. It was indicated that for a magnetic field parallel to temperature gradient, the thermal conductivity component along the magnetic field was significantly enhanced due to the magnetic field induced chain-like magnetic nanoparticles aggregates. The experimental data of thermal conductivity enhancement along the magnetic field direction were similar to those predicted by the proposed model. (C) 2012 Elsevier Inc. All rights reserved.