Abstract Endwall film cooling upstream of the leading edge (LE) of a vane presents a relatively complex flow phenomenon due to the horseshoe vortices (HVs) generated at the LE region. Upstream of the LE region, the coolant flow has difficulties to eject out. This research work focuses on controlling the jet holes coolant coverage upstream of the LE region. Compound angle holes in staggered arrangement are introduced and applied in the LE region to increase the coolant coverage. Six different arrangements of cooling holes are designed, with variations from one row or two rows arrangements, parallel or staggered arrangements, normal cylindrical holes or compound angle holes. Besides cooling holes with different shapes and arrangements, effect of the blowing ratio (BR) and turbulence intensity (TI) are also considered. The BR ranges from 1 to 3 and TI ranges from 1.3% to 15%. The calculated results show that the film cooling holes upstream of the LE of a vane have significant cooling effects on both the vane surfaces and the endwall. At small BRs, the film cooling effectiveness (η) on the endwall is considerable. When the BR is increased, the η on the vane surfaces is increased more quickly and becomes dominant. The coolant coverage in the vane-endwall junction region are not affected by the mainstream turbulence intensity and almost keep the same with the varied turbulence intensities. A single row of cylindrical holes (Case 1) and two rows of compound angle holes with staggered arrangement (Case 5) have relatively high overall averaged cooling effectiveness compared with other cases at different BRs. In addition, the high averaged cooling effectiveness on the endwall and vane surfaces by Case 5 is not affected by a change of the BRs.

中文翻译：

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涡轮叶片前缘上游端壁薄膜冷却孔设计

摘要 由于在 LE 区域产生的马蹄涡 (HV)，叶片前缘 (LE) 上游的端壁薄膜冷却呈现出相对复杂的流动现象。在 LE 区域的上游，冷却剂流难以排出。这项研究工作的重点是控制 LE 区域上游的喷射孔冷却剂覆盖率。在LE区域引入并应用交错排列的复合角孔，以增加冷却剂覆盖率。设计了六种不同的冷却孔排列方式，从一排或两排排列，平行或交错排列，普通圆柱孔或复合角孔排列。除了不同形状和排列的冷却孔外，还考虑了鼓风比（BR）和湍流强度（TI）的影响。BR 范围从 1 到 3，TI 范围从 1.3% 到 15%。计算结果表明，叶片 LE 上游的薄膜冷却孔对叶片表面和端壁都有显着的冷却效果。在小 BR 处，端壁上的薄膜冷却效率 (η) 是可观的。当 BR 增加时，叶片表面上的 η 增加得更快并成为主导。叶片端壁连接区冷却液覆盖率不受主流湍流强度的影响，几乎与不同的湍流强度保持一致。单排圆柱孔（案例1）和两排交错排列的复合角孔（案例5）与不同BR的其他情况相比，整体平均冷却效率相对较高。此外，