Rheological behaviour of ethylene glycol-titanate nanotube nanofluids
Rheological behaviour of ethylene glycol-titanate nanotube nanofluids
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DOI：
10.1007/s11051-009-9599-9
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发表时间：
2009-08-01
影响因子：
2.5
通讯作者：
Fan, Xiaolei
中科院分区：
文献类型：
--
作者：
Chen, Haisheng;Ding, Yulong;Fan, Xiaolei
实验工作已经进行了乙二醇基纳米流体的流变行为，包含钛酸酯纳米管超过20-60摄氏度和0- 8%的颗粒质量浓度。结果发现，纳米流体表现出剪切稀化行为，特别是在颗粒浓度超过类似于2%。温度对纳米流体的流变行为施加了非常强的影响，温度越高，剪切稀化越强。对于给定的颗粒浓度，存在一定的剪切速率，低于该剪切速率，粘度随温度升高而增加，而高于该剪切速率则相反。然而，相对于基础液体粘度的标准化高剪切粘度与温度无关。进一步的分析表明，温度效应是由于布朗扩散和对流对粘性的相对贡献的剪切依赖性。分析还表明，颗粒聚集和颗粒形状效应的组合是所观察到的高剪切流变行为的机制，这也支持的热导率测量和分析。
Experimental work has been performed on the rheological behaviour of ethylene glycol based nanofluids containing titanate nanotubes over 20-60 degrees C and a particle mass concentration of 0-8%. It is found that the nanofluids show shear-thinning behaviour particularly at particle concentrations in excess of similar to 2%. Temperature imposes a very strong effect on the rheological behaviour of the nanofluids with higher temperatures giving stronger shear thinning. For a given particle concentration, there exists a certain shear rate below which the viscosity increases with increasing temperature, whereas the reverse occurs above such a shear rate. The normalised high-shear viscosity with respect to the base liquid viscosity, however, is independent of temperature. Further analyses suggest that the temperature effects are due to the shear-dependence of the relative contributions to the viscosity of the Brownian diffusion and convection. The analyses also suggest that a combination of particle aggregation and particle shape effects is the mechanism for the observed high-shear rheological behaviour, which is also supported by the thermal conductivity measurements and analyses.