Analysis of enhanced heat transfer by magnetic nanofluids in a mini channel under hard/soft-magnetic elements. (11th October 2018)

• Record Type: Journal Article
• Authors: Sun, Jiajia; Shi, Zongqian; Chen, Shuang; Jia, Shenli
• Is Part Of: Journal of physics. Volume 51:Number 48(2018)
• Publication Date: 2018-10-11
• Subjects: magnetic nanofluids -- heat transfer -- mixture model -- soft-magnetic element/hard-magnetic element -- magnetic field; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aae367
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: The heat transfer characteristic of magnetic nanofluid in a 2D channel, below which a current-carrying wire or hard-magnetic elements (HMEs)/soft-magnet elements (SMEs) are embedded, is analyzed using a two-phase mixture model. The magnetic field produced by the current-carrying wire, the HMEs or the magnetized SMEs permeates into the channel giving rise to an attractive Kelvin force on the magnetic nanofluids. An equivalent charge method is adopted to obtain a closed-form field analysis, which can be combined with numerical hydrodynamic analysis to predict the heat transfer process of the magnetic nanofluids. The heat transfer characteristics of the magnetic nanofluids in the presence of a current-carrying wire or an HME are compared, which denotes that one HME with a certain configuration can provide sufficient Kelvin force to control the behavior of the magnetic nanofluids without introducing additional heat. To further enhance the heat transfer, two HMEs are proposed. In addition, an SME is introduced to improve the heat transfer of the magnetic nanofluid, which can also implement the function of switching on/off by applying or removing the external magnetic field.