In this paper, reference values and reference correlations for the thermal conductivity and viscosity of pure fluids are reviewed. Reference values and correlations for the thermal conductivity and the viscosity of pure fluids provide thoroughly evaluated data or functional forms and serve to help calibrate instruments, validate or extend models, and underpin some commercial transactions or designs, among other purposes. The criteria employed for the selection of thermal conductivity and viscosity reference values are also discussed; such values, which have the lowest uncertainties currently achievable, are typically adopted and promulgated by international bodies. Similar criteria are employed in the selection of reference correlations, which cover a wide range of conditions, and are often characterized by low uncertainties in their ranges of definition.

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Reference Values and Reference Correlations for the Thermal Conductivity and Viscosity of Fluids

The NIST REFPROP software program is a powerful tool for calculating thermophysical properties of industrially important fluids, and this manuscript describes the models implemented in, and features of, this software. REFPROP implements the most accurate models available for selected pure fluids and their mixtures that are valid over the entire fluid range including gas, liquid, and supercritical states, with the goal of uncertainties approaching the level of the underlying experimental data. The equations of state for thermodynamic properties are primarily of the Helmholtz energy form; a variety of models are implemented for the transport properties. We document the models for the 147 fluids included in the current version. A graphical user interface generates tables and provides extensive plotting capabilities. Properties can also be accessed through third-party apps or user-written code via the core property subroutines compiled into a shared library. REFPROP disseminates international standards in both the natural gas and refrigeration industries, as well as standards for water/steam.

https://pubs.acs.org/doi/pdf/10.1021/acs.iecr.2c01427

The NIST REFPROP Database for Highly Accurate Properties of Industrially Important Fluids

This paper presents new, wide-ranging correlations for the viscosity and thermal conductivity of n-undecane based on critically evaluated experimental data. The correlations are designed to be used with a recently published equation of state that is valid from the triple point to 700 K, at pressures up to 500 MPa, with densities below 776.86 kg m−3. The estimated uncertainty for the dilute-gas viscosity is 2.4%, and the estimated uncertainty for viscosity in the liquid phase for pressures up to 60 MPa over the temperature range 260 K–520 K is 5%. The estimated uncertainty is 3% for the thermal conductivity of the low-density gas and 3% for the liquid over the temperature range from 284 K to 677 K at pressures up to 400 MPa. Both correlations behave in a physically reasonable manner when extrapolated to the full range of the equation of state, but care should be taken when using the correlations outside of the validated range. The uncertainties will be larger outside of the validated range and also in the ...

Reference Correlations for the Viscosity and Thermal Conductivity of n-Undecane

This paper presents a new wide-ranging correlation for the viscosity of ammonia based on critically evaluated experimental data. The correlation is designed to be used with a recently developed equation of state, and it is valid from the triple point to 725 K at pressures up to 50 MPa. The estimated uncertainty varies depending on the temperature and pressure, from 0.6% to 5%. The correlation behaves in a physically reasonable manner when extrapolated to 100 MPa; however, care should be taken when using the correlation outside of the validated range.

Reference Correlation for the Viscosity of Ammonia from the Triple Point to 725 K and up to 50 MPa

Modeling the thermal conductivity of hydrofluorocarbons, hydrofluoroolefins and their binary mixtures using residual entropy scaling and cubic-plus-association equation of state

This paper presents new wide-ranging correlations for the viscosity and thermal conductivity of ethyl fluoride (R161) based on critically evaluated experimental data The correlations are designed to be used with a recently published equation of state that is valid from 130 to 450 K, at pressures up to 100 MPa The estimated uncertainty at a 95% confidence level is 2% for the viscosity of low-density gas (pressures below 05 MPa) and 3% for the viscosity of the liquid over the temperature range from 243 to 363 K at pressures up to 30 MPa The estimated uncertainty is 3% for the thermal conductivity of the low-density gas and 3% for the liquid over the temperature range from 234 to 374 K at pressures up to 20 MPa Both correlations may be used over the full range of the equation of state, but the uncertainties will be larger, especially in the critical region

/pdf/correlations-for-the-viscosity-and-thermal-conductivity-of-49byc04mrj.pdf

Ch. M. Tsolakidou

Papers

Correlations for the Viscosity and Thermal Conductivity of Ethyl Fluoride (R161).