Abstract
Examples of engineering interest in the crossover expressions for critical enhancement of thermophysical properties are explained. Designing and controlling a power plant, a chemical plant or various energy conversion machineries require very precise formulations, charts or computer softwares over a wide range of temperature and pressure including the critical region. Development of crossover expressions is needed for working fluids and fluids for energy conversion.
In the case of thermodynamic properties, approaches based on the combined equations of state using a so-called switching function often encounter serious troubles when derived functions are to be calculated. Other approaches include extention of an asymptotic scaling equation, extention of far-field analytic equation into the critical region and so on. Development of an universal theoretical expression of crossover is needed not only for scientific calculations but also for engineering applications.
