In view of the ever-increasing thermal load being placed on gas turbine blade endwalls, there is an urgent need to develop advanced endwall thermal management techniques. This paper proposes a non-axisymmetric endwall contouring method based on two parameterized control curves. The method is then applied to a blade endwall with an upstream purge flow. The effects of contoured endwalls with different maximum amplitudes on endwall aero-thermal performance are numerically investigated under three different mass flow ratios (MFR). The results indicate that, with endwall contouring, the strength of the horseshoe vortex and turbulent mixing of the mainstream and coolant can be both diminished, leading to a slightly lower aerodynamic loss. A contoured endwall significantly enhances the endwall film cooling effectiveness when MFR>1.0%, while having little impact when MFR = 0.5%, when compared to a flat endwall. More importantly, a contoured endwall significantly enlarges the film-cooling coverage near a blade leading edge, where the thermal load is extremely high. A contoured endwall with a maximum amplitude of 1.5% can substantially enhance the area-averaged film-cooling effectiveness by 41% when MFR = 1.0%. Furthermore, the contoured endwall also shows a considerable reduction in endwall heat transfer rates for all the MFRs investigated. It should be noted that the contouring amplitude for the lowest heat transfer rate also obtains the highest film cooling effectiveness when MFR>1.0%. The optimal contouring amplitude is found to be H/S = 1.5% and H/S = 1.0% for MFR = 1.0% and MFR = 1.5%, respectively. Overall, a contoured endwall with an appropriate contouring amplitude can significantly reduce the thermal load on endwalls, without any serious aerodynamic impact.

鉴于越来越多的热负荷施加在燃气轮机叶片端壁上，迫切需要开发先进的端壁热管理技术。本文提出了一种基于两条参数化控制曲线的非轴对称端壁轮廓法。然后将该方法应用于具有上游吹扫流的叶片端壁。在三种不同的质量流量比（MFR）下，数值研究了具有不同最大振幅的异形端壁对端壁空气热性能的影响。结果表明，利用端壁轮廓，马蹄涡流的强度以及主流和冷却剂的湍流混合都可以减小，从而导致空气动力损失稍低。当MFR> 1.0％时，轮廓成型的端壁可显着提高端壁膜的冷却效率，与平端墙相比，当MFR = 0.5％时几乎没有影响。更重要的是，轮廓化的端壁大大增加了叶片前缘附近的薄膜冷却范围，在叶片前缘，热负荷非常高。当MFR = 1.0％时，最大振幅为1.5％的异形端壁可以将平均面积的薄膜冷却效率提高41％。此外，对于所有研究的MFR，轮廓化的端壁还显示出端壁传热速率的显着降低。应当注意的是，当MFR＞ 1​​.0％时，最低传热速率的轮廓振幅也获得最高的薄膜冷却效率。对于MFR ＝ 1.0％和MFR ＝ 1.5％，发现最佳轮廓幅度分别为H / S ＝ 1.5％和H / S ＝ 1.0％。全面的，