IAPWS logo

IAPWS R18-21
Release on the IAPWS Formulation 2021 for the Thermal Conductivity of Heavy Water
September 2021

PDF of document

This formulation is recommended for the calculation of the thermal conductivity of heavy water in its fluid phases.
The formulation consists of a dilute-gas term that is only a function of temperature, a finite-density term as a function of temperature and density, and a critical enhancement term as a function of temperature and density. A simplified version of the critical enhancement term is supplied for simplified industrial use.
The region of validity the entire stable fluid region from the melting curve to 825 K at pressures up to 250 MPa. It extrapolates in a physically reasonable way outside this region.
The development of the formulation and comparisons to available data are described in detail in a scientific article.

Revision History

This Release is the product of the Working Group "Thermophysical Properties of Water and Steam" (TPWS) of the International Association for the Properties of Water and Steam (IAPWS).

This page updated March 9, 2022

iapws.org >> releases, guidelines, etc. >> IAPWS 2021 Formulation for Thermal Conductivity of Heavy Water