Abstract

This study presents an experimental investigation on forced convection heat transfer of ferrofluid between two parallel-plates in the presence of a static magnetic field (SMF). The heat transfer between two parallel-aluminum plates is studied, which heat source with a constant heat flux is applied on the bottom plate. The process of heat transfer is examined for DI-water and ferrofluid in the absence and the presence of the magnetic field. The heat transfer characteristics at the different flow rates, magnet distance from the test section (d = 2–80 mm) and nanoparticle volume fractions (ϕ = 0.25–2%wt) are compared to those of pure water. The results depicted that the heat transfer coefficient (h) and Nusselt number (Nu) of ferrofluid are higher than DI-water. In addition, the results show that applying SMF could enhance the convective heat transfer rate and it decreased by an increase in d that means the decrease in the magnetic field strength. The increase in the nanoparticle volume fraction leads to higher heat transfer enhancement. The maximum value of the heat transfer coefficient and Nusselt number are achieved for SMF with d = 2 mm and ϕ = 1% wt.

中文翻译：

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两平行板间铁磁流体强迫对流换热的实验研究

摘要

这项研究提出了在存在静磁场（SMF）的情况下两个平行板之间铁磁流体强迫对流换热的实验研究。研究了两个平行铝板之间的传热，将具有恒定热通量的热源施加在底板上。在不存在磁场和存在磁场的情况下，检查去离子水和铁磁流体的传热过程。与纯水相比，将不同流速，距测试部分的磁体距离（d = 2–80 mm）和纳米颗粒体积分数（ϕ = 0.25–2％wt）下的传热特性进行了比较。结果表明，铁磁流体的传热系数（h）和努塞尔数（Nu）均高于去离子水。此外，结果表明，应用SMF可以提高对流换热速率，并且随着d的增加而降低，这意味着磁场强度的降低。纳米颗粒体积分数的增加导致更高的热传递增强。对于d = 2 mm和ϕ = 1％wt的SMF，实现了传热系数和努塞尔特数的最大值。