ISSN 1810-2328, Journal of Engineering Thermophysics, 2017, Vol. 26, No. 4, pp. 580–597. c  Pleiades Publishing, Ltd., 2017. Eulerian–Eulerian Simulation of Non-Uniform Magnetic Field Eﬀects on the Ferroﬂuid Nucleate Pool Boiling R. Mortezazadeh 1 , H. Aminfar 1* , and M. Mohammadpourfard 2** 1 Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran 2 Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz, 5166616471 Iran Received October 19, 2015 Abstract—The nucleate pool boiling heat transfer of ferroﬂuid on a horizontal plate in the presence of a non-uniform magnetic ﬁeld has been studied numerically using Eulerian–Eulerian approach. Also, the wall partitioning model was extended to consider the boiling surface modiﬁcation by the nanoparticles deposition on the heated surface. Adding nanoparticles causes deterioration in the boiling heat transfer coeﬃcient and void fraction. Moreover, applying the magnetic ﬁeld intensiﬁes these reductions. DOI: 10.1134/S1810232817040129 1. INTRODUCTION Alongside the recent progress in technology and engineering devices, the desire for transferring a higher amount of heat is becoming more tangible. Boiling is a practical, unchallenged, and, simultane- ously, the best mechanism in the ﬁeld of heat transfer, which is found in the vast majority of industrial machines such as boiler and heat exchanger. Steam nucleation alters the system thermodynamic equilibrium; consequently, the bulk of heat removed from the boiling surface is increased substantially, even at low temperature diﬀerences, which is possibly a positive factor [1, 2]. However, the chain of this interaction between the liquid and vapor is not appealing at all. When the boiling surface becomes free from liquid and the vapor ﬁlm is established, the boiling heat transfer coeﬃcient (HTC) deteriorates dramatically and the surface temperature increases, known as the critical heat ﬂux point (CHF), or the ultimate limit of the vapor nucleation [3, 4]. The CHF occurrence can expose the system and the operation safety to some issues such as damage or deformation of materials [4–7]. Introducing nanoparticles, even at very low volume concentration, into the base liquid oﬀers a great opportunity to overcome the boiling crisis and is anonymously reported in the experiments [3, 5, 8–11]. A vast number of nanoﬂuids pool boiling studies have reported a signiﬁcant increase in the CHF, although the eﬀects of adding the nanoparticles to the HTC still remain as a controversial challenge. The statistics and trends of the HTC enhancement and deterioration along with the CHF increase rate can be found in [7, 9]. A general theory that can estimate the CHF point precisely is still far beyond the horizon, although several studies have classiﬁed main parameters such as contact angles, thermophysical properties, surface roughness, wettability and operational pressure that aﬀect the boiling phenomenon [12–15]. The deposition of nanoparticles on the boiling surface was observed in [4, 16–18] and reported as the most contributing parameter providing a new means to improve the heated surface characteristics that inﬂuenced nucleate boiling. A good review of the eﬀects of the deposited nanoparticles on the surface characteristics like nucle- ation site density, wettability, contact angle and roughness can be found in the work of [19]. Because of the stationary state in the pool boiling and the microlayer evaporations of the undetached vapor bubble in the nucleation site, the concentration of nanoparticles in this area is intensiﬁed. Consequently, the * E-mail: hh_aminfar@tabrizu.ac.ir ** E-mail: Mohammadpour@tabrizu.ac.ir 580