To understand the remarkable enhancements in viscosity and thermal conductivity of nanofluids, a molecular dynamics (MD) simulation approach was used to investigate the structure and thickness of the interfacial layer and obtain values for radial distribution function, g(r), viscosity, and thermal conductivity of Cu/water nanofluids with volume fractions and temperatures ranging from 0.5–2 vol% and 293–333 K, respectively. The results revealed that value of g(r) was much higher in the first molecular nanolayer compared to the second layer, indicating that greater numbers of water molecules are present in the first layer, which reduces contact thermal resistance and improves thermal conductivity of nanofluids. Moreover, while value of g(r) increased with increasing Cu volume fraction and decreased with temperature, nanolayer thickness was unchanged with temperature at each volume fraction, indicating that intermolecular forces intensify in the first nanolayer. Macroscopically, viscosity and thermal conductivity of the nanofluids increased at higher volume fractions, showing increases of 71.7% and 75% for viscosity, and 41.7% and 53.3% for thermal conductivity at 0.5 and 2 vol%, respectively, compared to water at 333 K. These results, although obtained for Cu/water systems, can provide useful insights into structural and transport properties of nanofluids in general.

为了了解纳米流体的粘度和导热性的显着提高，使用了分子动力学（MD）模拟方法来研究界面层的结构和厚度，并获得径向分布函数，g（r），粘度和热值铜/水纳米流体的电导率，体积分数和温度分别为0.5–2 vol％和293–333K。结果表明，g（r与第二层相比，第一分子纳米层中的）高得多，表明第一层中存在更多的水分子，这降低了接触热阻并提高了纳米流体的导热性。而且，当g（r随铜体积分数的增加而增加，而随温度的降低而减小，在每个体积分数下，纳米层的厚度均随温度而变化，表明分子间力在第一纳米层中增强。宏观上，与333 K的水相比，纳米流体的粘度和热导率在较高的体积分数下会增加，分别显示在0.5和2 vol％时，粘度分别增加71.7％和75％，热导率分别增加41.7％和53.3％。这些结果，尽管是从铜/水系统获得的，但通常可以提供有关纳米流体的结构和传输特性的有用见解。