Quiñones-Cisneros Sergio E, Deiters Ulrich K
Institute of Physical Chemistry, University of Cologne, Luxemburger Str. 116, D-50939 Koeln, Germany.
J Phys Chem B. 2006 Jun 29;110(25):12820-34. doi: 10.1021/jp0618577.
The friction theory (FT) approach relates the viscosity of a fluid to its equation of state (EoS), and it is known to give good results for a large number of compounds over wide ranges of temperature and pressure. Previous FT versions were restricted to use EoS of the van der Waals type, i.e., EoS explicitly consisting of a repulsive and an attractive term, which limited the number of usable EoS as well as the accuracy of the viscosity predictions. In this work, the restriction is removed by means of a pragmatic generalized definition of repulsive and attractive terms based on the internal pressure concept. As a result, the FT theory can be extended to practically all types of EoS, from theoretical ones (e.g., EoS based on thermostatistical or renormalization theories) to the highly accurate empirical reference EoS. In combination with the later, the FT is shown to represent experimental viscosity data for several fluids, including water, with an accuracy as high as that required for reference models. Additionally, some relevant phenomena, such as the critical anomaly, appear to follow naturally from the physics already built into the EoS.
摩擦理论（FT）方法将流体的粘度与其状态方程（EoS）相关联，并且已知在很宽的温度和压力范围内，该方法对大量化合物都能给出良好的结果。以前的FT版本仅限于使用范德华类型的状态方程，即明确由排斥项和吸引项组成的状态方程，这限制了可用状态方程的数量以及粘度预测的准确性。在这项工作中，基于内压概念，通过对排斥项和吸引项进行实用的广义定义，消除了这一限制。结果，FT理论可以扩展到几乎所有类型的状态方程，从理论性的（例如基于热统计或重整化理论的状态方程）到高度精确的经验参考状态方程。与后者相结合时，FT被证明能够以与参考模型所需精度一样高的精度表示包括水在内的几种流体的实验粘度数据。此外，一些相关现象，如临界异常，似乎自然地源于状态方程中已有的物理原理。
