Transport properties of real moist air, dry air, steam, and water. (21st January 2021) - Herrmann, Sebastian
Abstract : This paper presents the ASHRAE transport properties model for moist air as a "real-gas mixture" employing a modification of the mixing model of Vesovic and Wakeham. It uses the latest research from the International Association for the Properties of Water and Steam (IAPWS), the International Union of Pure and Applied Chemistry (IUPAC), and the National Institute of Standards and Technology (NIST). The modification represents an improvement and consists in an adjustment of the underlying Vesovic-Wakeham model to experimental data in accordance with the composition of the mixture moist air. The model allows the calculation of viscosity and thermal conductivity in the validity range with total pressures from 0.01 kPa to 10 MPa, temperatures from −70 to 300 °C, and humidity ratios from 0 to 10 kgw /kga . The model has been used to generate transport property tables for moist air and for H2 O at saturation states for the Psychrometrics Chapter in the 2021 ASHRAE Handbook Fundamentals. This work summarizes the results of the ASHRAE Research Project 1767 (RP-1767).