Laesecke Arno, Muzny Chris D
National Institute of Standards and Technology, Material Measurement Laboratory, Applied Chemicals and Materials Division.
J Phys Chem Ref Data. 2017;46. doi: 10.1063/1.4977429. Epub 2017 Mar 20.
A comprehensive database of experimental and computed data for the viscosity of carbon dioxide (CO) was compiled and a new reference correlation was developed. Literature results based on an potential energy surface were the foundation of the correlation of the viscosity in the limit of zero density in the temperature range from 100 K to 2000 K. Guided symbolic regression was employed to obtain a new functional form that extrapolates correctly to → 0 K and to 10 000 K. Coordinated measurements at low density made it possible to implement the temperature dependence of the Rainwater-Friend theory in the linear-in-density viscosity term. The residual viscosity could be formulated with a scaling term / the significance of which was confirmed by symbolic regression. The final viscosity correlation covers temperatures from 100 K to 2000 K for gaseous CO, and from 220 K to 700 K with pressures along the melting line up to 8000 MPa for compressed and supercritical liquid states. The data representation is more accurate than with the previous correlations, and the covered pressure and temperature range is significantly extended. The critical enhancement of the viscosity of CO is included in the new correlation.
编制了一个关于二氧化碳（CO₂）粘度的实验数据和计算数据的综合数据库，并开发了一种新的参考关联式。基于势能面的文献结果是在100 K至2000 K温度范围内零密度极限下粘度关联的基础。采用引导式符号回归来获得一种新的函数形式，该形式能正确外推至T→0 K和10000 K。在低密度下的协同测量使得能够在密度线性的粘度项中体现雨水-弗伦德理论的温度依赖性。残余粘度可以用一个标度项η/η₀来表示，其重要性通过符号回归得到证实。最终的粘度关联式涵盖了气态CO₂在100 K至2000 K的温度范围，以及压缩和超临界液态在220 K至700 K且沿熔点压力高达8000 MPa的情况。数据表示比以前的关联式更准确，并且涵盖的压力和温度范围显著扩展。新的关联式包含了CO₂粘度的临界增强。
