Morioka S
Key Laboratory of Liquid Structure and Heredity of Materials, College of Materials Science and Engineering, Shandong University, Jinan, Shandong 250061, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Nov;72(5 Pt 1):051203. doi: 10.1103/PhysRevE.72.051203. Epub 2005 Nov 17.
An improved formula of shear viscosity for liquids is presented by introducing a phenomenological viscous factor in the nonequilibrium term in the doublet distribution function, which improves an incomplete formula of shear viscosity presented in an early work of Born and Green. The phenomenological viscous factor effectively counts some higher-order interactions, and is constrained so that, in the limit of hard-sphere liquids, the magnitude of the improved formula of shear viscosity reduces to that of Enskog for dense fluids. The improved formula does not require any adjustable parameters except for the pair potential to describe liquids. In order to verify the improved formula, a liquid of Ar near the triple point is studied in detail. In addition, liquids of Pb in wide ranges of temperature are examined to test the temperature dependence of the phenomenological viscous factor. Here an available integral equation is employed to calculate the radial distribution function by prescribed pair potentials. One finds that the present formula is capable to describe the shear viscosity in accord with those of experimental data for both cases of Ar and Pb. The phenomenological viscous factor plays a crucial role in the evaluation of shear viscosity for liquids.
通过在双重分布函数的非平衡项中引入一个唯象粘性因子，给出了一种改进的液体剪切粘度公式，该公式改进了玻恩和格林早期工作中给出的不完整的剪切粘度公式。唯象粘性因子有效地考虑了一些高阶相互作用，并受到约束，使得在硬球液体的极限情况下，改进后的剪切粘度公式的大小在高密度流体时降至恩斯科格公式的大小。除了用于描述液体的对势外，改进后的公式不需要任何可调参数。为了验证改进后的公式，详细研究了处于三相点附近的氩液体。此外，还研究了宽温度范围内的铅液体，以测试唯象粘性因子的温度依赖性。这里采用一个可用的积分方程，通过规定的对势来计算径向分布函数。人们发现，对于氩和铅这两种情况，本公式都能够与实验数据一致地描述剪切粘度。唯象粘性因子在液体剪切粘度的评估中起着关键作用。
