Experimental data for the viscosity and thermal conductivity of water and steam

As part of a joint project between the International Association for the Properties of Water and Steam and the Subcommittee on Transport Properties of the International Union of Pure and Applied Chemistry Commission I.2 on Thermodynamics, all available and reliable experimental data on the viscosity and thermal conductivity of ordinary water and steam have been collected and converted to the current temperature scale (ITS-90) and a common set of units. The data are grouped according to state into four regions: the liquid phase (excluding data near 0.101 325 MPa), the steam (vapor) phase, the supercritical region (T>T-c for any pressure), and liquid water at ambient pressure (near 0.101 325 MPa) between the triple-point temperature and the normal boiling-point temperature. For each point with measured temperature and pressure (or at specified saturation conditions), a density has been computed with the current scientific standard thermodynamic formulation (IAPWS-95), and each experimental datum has been compared with the viscosity or thermal conductivity calculated from the current standard formulations for these properties. The total data collection contains 4090 points for viscosity in the range of temperatures from 238 to 1346 K with pressures to 346 MPa and 5107 points for thermal conductivity in the range of temperatures from 256 to 1191 K with pressures to 785 MPa. The current standard IAPWS formulations for the transport properties of water are based on correlations adopted in 1984 which considered experimental data available through 1980. The present study considers all data available in the earlier work, data collected in bibliographic efforts within IAPWS and documented in unpublished reports through 1988, and additional data published subsequent to the earlier reports or, in some cases, older data which were not considered in the previous compilations. Thus, this study has identified new data which were not available for the previous reviews of the transport properties of water, has identified regions in which the current standard transport property formulations can now be improved, and is intended to facilitate the development of new, more accurate, international formulations for the viscosity and thermal conductivity of water and steam. (C) 2000 American Institute of Physics. [S0047-2689(00)00202-].