^3He状态方程框架及热力学性质推导

THE FRAMEWORK OF STATE EQUATION FOR HELIUM-3 AND THE DERIVATION OF THERMODYNAMIC PROPERTIES

构建了低温流体3He状态方程的总体研究框架 ,以温度和密度为独立变量 ,采用Helmholtz能形式表述3He的热力性质依赖关系。在此基础上 ,推导了基于Helmholtz能形式基本状态方程的各热力学性质表达式。若对pVT ,比热容、(dp/dT) ρ,(dp/dρ) T 以及声速等实验数据一起进行最小二乘拟合 ,通过适当地选取方程形式、筛选实验数据以及赋以相应权重等技术手段 ,可产生同时适用于正常相液体以及气体区的解析形式3He热力学状态方程。

The main framework of the equation of state for the cryogenic fluid 3He is constructed. In this framework,the temperature and the density are treated as the independent input variables and the helmholtz energy as the dependent variable. All the other thermodynamic property expressions are obtained by derivation of helmholtz energy with respect to temperature or density or both of them. The form of the equation of state and those derived property expressions together show the thermodynamic consistency, feasibility and advantages of the framework. The principle of data selection and weighting, the fundamental requirements and the criteria of the future equation of state are presented. The least-squares fitting to the experimental data consisted of p-ρ-T, specific heat capacity, (dp/dT) ρ, (dp/dρ) T and velocity of sound are briefly introduced.