Chereches Elena Ionela, Minea Alina Adriana
Faculty of Materials Science and Engineering, Technical University "Gh. Asachi" of Iasi, Bd. D. Mangeron no. 63, Iasi 700050, Romania.
Nanomaterials (Basel). 2019 Aug 29;9(9):1228. doi: 10.3390/nano9091228.
In this research, the electrical conductivity of simple and hybrid nanofluids containing AlO, TiO and SiO nanoparticles and water as the base fluid was experimentally studied at ambient temperature and with temperature variation in the range of 20-60 °C. A comparison of the experimental data with existing theoretical models demonstrated that the theoretical models under-predict the experimental data. Consequently, several correlations were developed for nanofluid electrical conductivity estimation in relation to temperature and volume concentration. The electrical conductivity of both simple and hybrid nanofluids increased linearly with both volume concentration and temperature upsurge. More precisely, by adding nanoparticles to water, the electrical conductivity increased from 11 times up to 58 times for both simple and hybrid nanofluids, with the maximum values being attained for the 3% volume concentration. Plus, a three-dimensional regression analysis was performed to correlate the electrical conductivity with temperature and volume fraction of the titania and silica nanofluids. The thermo-electrical conductivity ratio has been calculated based on electrical conductivity experimental results and previously determined thermal conductivity. Very low figures were noticed. Concluding, one may affirm that further experimental work is needed to completely elucidate the behavior of nanofluids in terms of electrical conductivity.
在本研究中,以水为基液,对含有AlO、TiO和SiO纳米颗粒的单一和混合纳米流体在环境温度以及20 - 60°C温度范围内的电导率进行了实验研究。将实验数据与现有理论模型进行比较表明,理论模型对实验数据的预测偏低。因此,针对纳米流体电导率与温度和体积浓度的关系,建立了几个相关性方程。单一和混合纳米流体的电导率均随体积浓度和温度升高呈线性增加。更确切地说,通过向水中添加纳米颗粒,单一和混合纳米流体的电导率增加了11倍至58倍,在体积浓度为3%时达到最大值。此外,进行了三维回归分析,以关联二氧化钛和二氧化硅纳米流体的电导率与温度及体积分数。基于电导率实验结果和先前测定的热导率计算了热电导率比。结果发现该比值非常低。总之,可以肯定的是,需要进一步开展实验工作,以全面阐明纳米流体在电导率方面的行为。