The paper contains new, representative equations for the viscosity and thermal conductivity of carbon dioxide. The equations are based in part upon a body of experimental data that have been critically assessed for internal consistency and for agreement with theory whenever possible. In the case of the low-density thermal conductivity at high temperatures, all available data are shown to be inconsistent with theoretical expectation and have therefore been abandoned in favor of a theoretical prediction. Similarly, the liquid-phase thermal conductivity has been predicted owing to the small extent and poor quality of the experimental information. In the same phase the inconsistencies between the various literature reports of viscosity measurements cannot be resolved and new measurements are necessary. In the critical region the experimentally observed enhancements of both trans: port properties are well represented by theoretically based equations containing just one adjustable parameter. The complete correlations cover the temperature range 200 K~T < 1500 K for viscosity and 200 K~T~l000 K for thermal conductivity, ~nd pressures up to 100 MPa. The uncertainties associated with the correlation vary according to the thermodynamic state from ± 0.3% for the viscosity of the dilute gas near room temperature to ± 5% for the thermal conductivity in the liquid phase. Tables of the viscosity and thermal conductivity generated by the representative equations are provided to assist with the confirmation of computer implementations of the calculation procedure.
This paper describes improved international formulations for the viscosity and thermal conductivity of water substance recently adopted by the International Association for the Properties of Steam.
Experimental evidepce for steam and other fluids has demonstrated the existence of an anomalous enhancement of [he dynamic viscosity in the close vicinity of the critical point. A re-analysis of the experimental evidence for the viscosity of steam indicates that the observed behavior of the critical viscosity enhancement is consistent with current theoretical predictions. An interpolating equation for the dynamic viscosity of water substance is presented which is in good agreement with the experimental viscosity data in a large range of temperatures and pressures. The equation contains a smaller number of coefficients than the current international equation for the viscosity of water substance and incorporates the enhancement of the viscosity in the close vicinity of tht:: critical point.
The paper documents the development of the available information for the thermal conductivity offluid H 2 0 since the promulgation ofthe first international formulation for the transport properties of water substance in 1964. As a result of this development, the International Association for" the Properties of Steam has adopted new recommended interpolating equations for the thermal conductivity of fluid H 2 0 at pressures up to 100 MPa and at temperatures up to 800 0c. These new international equations are discussed.
A new representation of the viscosity of ammonia is presented. The representative equations are based on a set of experimental data selected as a result of a critical assessment of the available information. The validity of the representation extends from 196 K to the critical temperature for both liquid and vapor phases. In the supercritical region the temperature range extends to 680 K for pressures at or below ambient and to 600 K for pressures up to 50 MPa. The accuracy of the representation varies from 0.5% for the viscosity of the dilute gas phase at moderate temperatures to about 5% for the viscosity at high pressures and temperatures. Tables of the viscosity generated by the correlating equation at selected temperatures and pressures and along the saturation line are presented to provide easy reference as well as for the validation of computer codes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.