Thermophysical properties of supercritical fluids and fluid mixtures

Technical Report · Mon Jul 01 00:00:00 EDT 1991

OSTI ID:5665334

Sengers, J V

This research is concerned with the development of a quantitative scientific description of the thermodynamic and transport properties of supercritical and subcritical fluids and fluid mixtures. It is known that the thermophysical properties of fluids and fluid mixtures asymptotically close to the critical point satisfy scaling laws with universal critical exponents and universal scaling functions. However, the range of validity of these asymptotic scaling laws is quite small. As a consequence, the impact of the modern theory of critical phenomena on chemical engineering has been limited. On the other hand, an a priori estimate of the range of temperatures and densities, where critical fluctuations become significant, can be made on the basis of the so-called Ginzburg criterion. A recent analysis of this criterion suggests that this range is actually quite large and for a fluid like carbon dioxide can easily extend to 100 degrees or so above the critical temperature. Hence, the use of traditional engineering equations like cubic equations is not scientifically justified in a very wide range of temperatures and densities around the critical point. We have therefore embarked on a scientific approach to deal with the global effects of critical fluctuations on the thermophysical properties of fluids and fluid mixtures. For this purpose it is not sufficient to consider the asymptotic critical fluctuations but we need to deal also with the nonasymptotic critical fluctuations. The goal is to develop scientifically based questions that account for the crossover of the thermophysical properties from their asymptotic singular behavior in the near vicinity of the critical point to their regular behavior very far away from the critical point.

• Research Organization: Maryland Univ., College Park, MD (United States). Inst. for Physical Science and Technology
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG05-88ER13902
• OSTI ID: 5665334
• Report Number(s): DOE/ER/13902-3; ON: DE91015794
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL FLOW
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
MIXTURES
TURBULENT FLOW
FLUCTUATIONS
GINZBURG-PITAEVSKII THEORY
PROGRESS REPORT
SPECIFIC HEAT
SUPERCRITICAL STATE
TEMPERATURE DEPENDENCE
TRANSPORT THEORY
DISPERSIONS
DOCUMENT TYPES
FLUID FLOW
VARIATIONS
640410* - Fluid Physics- General Fluid Dynamics