Role of microconvection induced by Brownian motion of nanoparticles in the enhanced thermal conductivity of stable nanofluids
Role of microconvection induced by Brownian motion of nanoparticles in the enhanced thermal conductivity of stable nanofluids
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DOI：
10.1063/1.3147855
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发表时间：
2009-06
影响因子：
4
通讯作者：
P. Shima;J. Philip;B. Raj
中科院分区：
文献类型：
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作者：
P. Shima;J. Philip;B. Raj
我们研究了纳米颗粒布朗运动引起的微对流对平均直径为2.8-9.5 nm的稳定纳米流体导热性增强的作用。纳米流体的有效导热系数（k/kf）随着颗粒直径的增加从1.05增加到1.25。当纳米流体中线性链的长径比增加时，观察到热导率有很大的增强。这些发现证实，微对流不是纳米流体中热导率增强的关键机制，而聚集具有更突出的作用。
We investigate the role of microconvection induced by Brownian motion of nanoparticles on thermal conductivity enhancement in stable nanofluids containing nanoparticles of average diameters 2.8–9.5 nm. Nanofluids with a fixed particle loading of 5.5 vol. %, the effective thermal conductivity (k/kf) increases from 1.05 to 1.25 with increasing particle diameter. Upon increasing the aspect ratio of the linear chains in nanofluids, very large enhancement of thermal conductivity is observed. These findings confirm that microconvection is not the key mechanism responsible for thermal conductivity enhancements in nanofluids whereas aggregation has a more prominent role.