New International Formulation for the Viscosity of Heavy Water

The International Association for the Properties of Water and Steam has recently adopted a new formulation for the thermodynamic properties of heavy water. This manuscript describes the development of a new formulation for the viscosity of heavy water that is consistent with the new equation of state and is valid for fluid states up to 775 K and 960 MPa with uncertainties ranging from 1% to 5% depending on the state point. Comparisons with experimental data and with a previous viscosity formulation are presented. The new formulation contains terms for the enhancement of viscosity in a small region near the critical point that were not included in previous formulations. The new formulation is applicable over a wider range of conditions than previous correlations.