A comprehensive database of experimental and computed data for the viscosity of carbon dioxide (CO2) was compiled and a new reference correlation was developed. Literature results based on an ab initio 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 T → 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 ργ /T the significance of which was confirmed by symbolic regression. The final viscosity correlation covers temperatures from 100 K to 2000 K for gaseous CO2, 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 CO2 is included in the new correlation.

中文翻译：

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二氧化碳粘度的参考相关性

编制了二氧化碳 (CO2) 粘度的实验和计算数据的综合数据库，并开发了新的参考相关性。基于 ab initio 势能面的文献结果是 100 K 至 2000 K 温度范围内零密度极限下粘度相关性的基础。 采用引导符号回归获得新的正确外推的函数形式到 T → 0 K 和到 10 000 K。低密度下的协调测量使得在线性密度粘度项中实现 Rainwater-Friend 理论的温度依赖性成为可能。残余粘度可以用标度项 ργ /T 公式化，其重要性通过符号回归得到证实。最终的粘度相关性涵盖 100 K 至 2000 K 的气态 CO2 温度，以及 220 K 至 700 K 的温度，压缩和超临界液态沿熔化线的压力高达 8000 MPa。数据表示比以前的相关性更准确，覆盖的压力和温度范围显着扩展。CO2 粘度的关键增强包含在新的相关性中。