Forced convection of a temperature-sensitive ferrofluid in presence of magnetic field of electrical current-carrying wire: A two-phase approach

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 29; no. 9; pp. 2168 - 2175
• Main Authors: Hangi, Morteza, Bahiraei, Mehdi, Rahbari, Alireza
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2018
• Subjects: Forced convection; Heat transfer enhancement; Magnetic field; Temperature-sensitive ferrofluid; Two-phase mixture model; Heat transfer enhancement; Forced convection; Temperature-sensitive ferrofluid; Magnetic field; Two-phase mixture model
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2018.05.026

[Display omitted] •Forced convection of a temperature-sensitive ferrofluid is assessed in a tube.•Ferrofluid is exposed to magnetic field produced by a current-carrying wire.•The two-phase mixture model is employed for the simulations.•Effect of magnetic field enhances with increasing field strength and reducing Re.•Placing two wires above and under the tube enhances flow mixing and heat transfer. This research examines laminar forced convection of a temperature-sensitive magnetic nanofluid flowing within a horizontal tube through the two-phase mixture model. The ferrofluid flowing in the tube is exposed to the magnetic field generated by electrical current-carrying wire(s) along the tube, and the effect of such magnetic field is studied on heat and mass transfer phenomena. It is observed that due to the dependency of magnetization on temperature, the cold fluid flowing at the central regions of the tube is attracted more significantly towards the source of the magnetic field, which results in creation of secondary flow. Such mixing in the flow, subsequently, disturbs the thermal and hydrodynamic boundary layers, especially at the vicinity of the magnetic field source, leading to better heat transfer rate and also higher pressure drop. Furthermore, increasing the strength of the magnetic field leads to greater enhancement in heat transfer, while increasing the Reynolds number decreases the effectiveness of the magnetic field on the ferrofluid flow and heat transfer. Moreover, placing two wires above and under the tube can enhance the heat transfer even more significantly, such that the average convective heat transfer coefficient in this case is about 34.5% higher than that of the case without magnetic field.