Experimental analysis of magnetic field effect on the pool boiling heat transfer of a ferrofluid

In this research, an experimental study was conducted to investigate the pool boiling heat transfer of Fe3O4/water nanofluid (ferrofluid) in the atmospheric pressure. This study also investigated the influence of the magnetic field on the rate of boiling heat transfer of nanofluid. Deionized (DI) water was used to examine the repeatability, integrity and precision of the experimental apparatus where a well agreement with the existing correlations was observed. The investigation of various volume concentrations of nano fluid revealed that boiling heat transfer in high concentrations decreases with an increase of concentration while it rises with the increase of concentration in low concentrations. The boiling heat transfer coefficient at 0.1% volume concentration nanofluid was evaluated as optimal (increasing up to 43%). In addition, experimental studies showed that the presence of positive and negative magnetic field gradients decrease and increase the boiling heat transfer, respectively. The findings of this study showed that at higher concentrations of nanofluid, the effect of the magnetic field on nanoparticles is boosted. The results of the experiments indicated that adding nanoparticles would not necessarily increase the boiling heat transfer coefficient. In fact, the surface roughness and the magnetic field gradient on the boiling surface were the main factors that could affect the boiling heat transfer coefficient, significantly. (C) 2016 Elsevier Ltd. All rights reserved.