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IAPWS R17-20
Release on the IAPWS Formulation 2020 for the Viscosity of Heavy Water
September 2020

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This formulation is recommended for the calculation of the viscosity 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 near-critical term as a function of temperature and density. The near-critical term is negligible except very close to the critical point; it should be omitted for industrial use and may be omitted for other uses outside the critical region.
The region of validity the entire stable fluid region from the melting curve to 775 K at pressures to 100 MPa, to 473 K at pressures up to 200 MPa, and to 373 K at pressures up to 960 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 December 29, 2021

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