Abstract
The increasing interest in developing nanofluids in general and ferrofluids in particular offers a possibility of controlling and enhancing the flow and heat transfer in engineering processes. This paper attempts to review the benchmark thermo-physical and magnetic properties (thermal conductivity, convective heat transfer and viscosity) of ferrofluids reported in literature. The main focus of this review was to investigate the influence on the thermo-physical properties of a ferrofluid when external magnet field was applied. It was reported that the thermal conductivity of a ferrofluid could be up to 300 times that of base fluid and that the viscosity could also be increased due the formation of chain-like particle assembly in the magnetic field along the direction the thermal gradient. In addition recommendations for future work have drawn particularly in the area of understanding the magnetic nanoparticles distribution in the presence of magnetic field, developing realistic thermal conductivity models based on clustering and experimental validation of the theoretical models. (C) 2014 Elsevier Ltd. All rights reserved.