Liquid metal buoyancy driven convection heat transfer in a rectangular enclosure in the presence of a transverse magnetic field. (October 2017)

• Record Type: Journal Article
• Authors: Wang, Z.H.; Meng, X.; Ni, M.J.
• Is Part Of: International journal of heat and mass transfer. Volume 113(2017)
• Page Start: 514
• Page End: 523
• Publication Date: 2017-10
• Subjects: MHD buoyancy driven convection -- Heat transfer -- Liquid metal -- CFD -- UDV; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2017.05.121
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: UDV can penetrate liquid metal to give precise buoyancy driven convection velocity. Small magnetic field promotes natural convection. Strong magnetic field restrains it. The mechanism depends on Grashof number, Hartmann number and Prandtl number. We fit the natural convection Nusselt number equation under a strong magnetic field. Abstract: Liquid metal, an electrically conducting fluid, buoyancy driven convection heat transfer processes are fundamental problems in the design of the fusion reactor due to the influence of the large temperature difference and the strong magnetic field. An investigation of liquid metal buoyancy driven convection heat transfer is conducted in a rectangular enclosure with a square cross-section under the influence of a uniform horizontal magnetic field. Two opposite vertical walls are maintained at different temperatures and the other four walls are thermally insulating. The applied magnetic field is perpendicular to the temperature gradient. Ultrasound Doppler velocimetry measurement method is used to get natural convection velocity in different temperature difference and different magnetic field intensities. The flow is characterized by the external Grashof number, Gr, determined from the temperature difference of the side walls, and the Hartmann number, Ha, determined from the intensities of the imposed magnetic field. Two multiple linear regression models of the Nusselt number based on the Hartmann layers theory are summarized which indicate that the induced current's restraining influence determines the natural convection heat transfer process of viscous electric liquids in a strong magnetic field.