准确描述流体输运性质，对于基础研究和工业应用都具有重要意义。输运性质决定了流体的流动、换热、传质特性，是流体力学、传热传质学等相关学科研究必备的关键基础数据，在动力、制冷、化工、石油、航天等工程领域应用广泛。随着能源革命的纵深发展，针对流体输运性质的研究需要提高模型计算精度、探索更多流体种类、拓展模型适用范围。为此，本文采用剩余熵标度方法，期望探索输运性质半理论建模的新思路，结合状态方程并利用有限的实验数据基础，在更广阔的温度压力范围内实现实际流体输运性质的准确描述。以单原子的惰性气体为媒介，探索实际流体剩余熵标度的基本规律，定义了新的剩余熵标度。采用Soave-Redlich-Kwong（SRK）状态方程导出惰性气体的剩余熵，利用从头算给出的稀薄气体黏度数据并基于对比态原理建立了惰性稀薄气体输运性质模型。发现以相同温度下稀薄气体黏度、导热系数为参比算得的约化黏度、导热系数均为剩余熵的单调增函数，且不同种类惰性气体的函数规律相同，由此建立了惰性气体的输运性质模型。模型将黏度、导热系数随热力学状态的变化关系简化为近似线性的单变量函数关系，具有较好的外推性能。以制冷和中低温能源利用系统中应用广泛的氟代烃类物质为媒介，将新剩余熵标度推广应用于结构各异的多原子分子体系。采用立方缔合状态方程导出剩余熵，探索引入旋转振动贡献后导热系数的剩余熵标度规律，建立了通用于氟代烃的剩余熵标度输运性质模型。通过引入标度特征参数将不同种类氟代烃体系的输运性质映射至同一剩余熵标度曲线；改进了新剩余熵标度中参比导热系数的计算形式；建立混合体系的标度特征参数混合规则，无需额外引入可调参数即可准确预测二元混合体系黏度和导热系数，将剩余熵标度推广应用于混合体系。针对剩余熵标度规律在近临界区的失效，以CO2为例，在新剩余熵标度中引入跨接方法。拟合了包含内核项的跨接比容平移SRK状态方程，并由之导出了剩余熵及输运性质跨接方法所需的热力学性质及流体特征参数。基于模式耦合理论导出的跨接函数分别计算了黏度和导热系数的临界增强效应，发现近临界区域输运性质背景项的约化值遵循同时适用于气相、液相及超临界区域的剩余熵标度规律，由此建立的新剩余熵标度模型可在包含近临界区域在内的宽广温度压力范围内实现黏度和导热系数的准确预测。
Transport properties determine the momentum, heat, and mass transfer characteristics of fluids. The accurate description of fluid transport properties is of great significance for both natural science disciplines such as fluid mechanics, heat and mass transfer, and industrial applications such as power, refrigeration, chemical, petroleum, aerospace, etc. The energy revolution in full swing calls for the fluid transport property modeling research on more fluid types, with higher accuracy and wider scope of application. This work adopts a novel approach to accurately represent the transport properties of real fluids in wide ranges of temperature and pressure using residual entropy scaling incorporating the equation of state with limited experimental data as reference.A novel residual entropy scaling is defined by exploring the basic law of residual entropy scaling for real fluids taking monoatomic noble gases as a demonstration. The residual entropy of noble gases is derived from the Soave-Redlich-Kwong （SRK） equation of state. The model of dilute gas transport property is developed for noble gases using the dilute gas viscosity data yielded by ab initio based on the principle of corresponding state. It is found that the reduced viscosity and thermal conductivity, taking the dilute gas viscosity and thermal conductivity at the same temperature as the reference, follow monotonically increasing functions of the residual entropy separately. The property of various noble gases are mapped onto the same curve using residual entropy scaling. The model simplifies the relationship between the viscosity or thermal conductivity and the thermodynamic state to an approximately linear univariate function and thus improves the accuracy of extrapolation.The novel residual entropy scaling is extended to polyatomic molecular systems with different structures, taking hydrofluorocarbons and hydrofluoroolefins, which are widely used in refrigeration and energy utilization systems under low and moderate temperatures, as a demonstration. The residual entropy is derived from the cubic-plus-association equation of state. The residual entropy scaling law is retested with the contribution of the internal （i.e., rotational or vibrational） freedom to the thermal conductivity of the polyatomic molecular systems. Then the definition of the reference thermal conductivity is revised for the novel residual entropy scaling of polyatomic molecular pure and mixture systems. The transport property of various hydrofluorocarbons and hydrofluoroolefins is mapped onto the same residual entropy scaling curve by introducing the rescaling parameter. The mixing rule of rescaling parameters is proposed, through which the viscosity and thermal conductivity of the binary mixing system can be accurately predicted without introducing additional adjustable parameters. The residual entropy scaling is thus extended to mixtures.Near the critical point, the conventional residual entropy scaling fails to describe the enhancement of the viscosity and thermal conductivity. To overcome this failure, the crossover residual entropy scaling incorporating the crossover method is proposed taking CO2 as a demonstration. A crossover volume-translation SRK equation of state with kernel term is fitted to accurately represent the thermodynamic parameters and properties in the residual entropy scaling and critical enhancement term. The critical enhancement of viscosity and thermal conductivity are determined separately using the crossover functions derived from the mode-coupling theory. The background part of the reduced transport property in the near-critical region also follows the univariate function of residual entropy, which is unified for the gaseous, liquid, and supercritical regions. Here, the novel residual entropy scaling model enables accurate representations of the viscosity and thermal conductivity over wide temperature and pressure ranges, including in the near-critical region.
