气流物性参数的选取与简化对提升涡轮叶片冷却性能预测的准确性具有重要意义。通过使用SSTk–ω 湍流模型结合γ-θ输运方程进行求解的方式研究了气流物性参数对叶片不同位置气膜冷却效率的影响。结果表明:物性参数对冷却效率的影响程度从高到低排序为密度、黏性系数、比热容、导热系数，按此优先级依次考虑各物性参数变化，可使叶片表面高温区域的分布特征接近真实工况；如果仅匹配密度参数，相对质量流量比MFRr≤1.0时，与气流工质的冷却效率偏差小于5%，相对质量流量比MFRr=1.6时，压力面和吸力面的偏差分别扩大至6.46%和12.23%；密度变化对气膜冷却性能的作用因气膜孔位置而异:压力面上密度提高仅在气膜贴壁良好时提升效率，而气膜脱离壁面时则降低效率；吸力面高密度冷气始终有利于增强贴附性并提高冷却效率。

The selection and simplification of airflow thermophysical properties are of great significance for improving the accuracy of cooling performance predictions in turbine blades. Using the SSTk–ω turbulence model combined with the γ-θ transport equation, the influence of airflow thermophysical properties on film cooling effectiveness at different blade locations was investigated. The results show that the degree of influence of thermophysical properties on cooling effectiveness, ranked from high to low, is density, viscosity coefficient, specific heat capacity, and thermal conductivity. Considering these parameter variations in order of priority allows the distribution characteristics of high-temperature regions on the blade surface to approach real operating conditions. If only the density parameter is matched, the deviation in cooling effectiveness relative to the airflow working medium is less than 5% when the relative mass flow ratio (MFRr) is ≤ 1.0. However, when MFRr = 1.6, the deviations on the pressure side and suction side increase to 6.46% and 12.23%, respectively. The effect of density variation on film cooling performance depends on the location of the film holes: on the pressure side, increased density only enhances effectiveness when the film adheres well to the wall, whereas it reduces effectiveness when the film detaches. On the suction side, higher-density coolant consistently improves adhesion and enhances cooling effectiveness.

国家自然科学(52306119)