Purpose

Endwall film cooling protects vane endwall by coolant coverage, especially at the leading edge (LE) region and vane-pressure side (PS) junction region. Strong flow impingement and complex vortexaa structures on the vane endwall cause difficulties for coolant flows to cover properly. This work aims at a full-scale arrangement of film cooling holes on the endwall which improves coolant efficiency in the LE region and vane-PS junction region.

Design/methodology/approach

The endwall film holes are grouped in four-holes constructal patterns. Three ways of arranging the groups are studied: based on the pressure field, the streamlines or the heat transfer field. The computational analysis is done with the k-ω SST model after validating the turbulence model properly.

Findings

By clustering the film cooling holes in four-holes patterns, the ejection of the coolant flow is stronger. The four-holes constructal patterns also improve the local coolant coverage in the “tough” regions, such as the junction region of the PS and the endwall. The arrangement based on streamlines distribution can effectively improve the coolant coverage and the arrangement based on the heat transfer distribution (HTD) has benefits by reducing high-temperature regions on the endwall.

Originality/value

A full-scale endwall film cooling design is presented considering interactions of different film cooling holes. A comprehensive model validation and mesh independence study are provided. The cooling holes pattern on the endwall is designed as four-holes constructal patterns combined with several arrangement choices, i.e. by pressure, by heat transfer and by streamline distributions.

中文翻译：

---

四孔型涡轮叶片端壁气膜冷却设计的数值研究

目的

端壁薄膜冷却通过冷却剂覆盖来保护叶片端壁，尤其是在前缘 (LE) 区域和叶片压力侧 (PS) 连接区域。叶片端壁上的强流冲击和复杂的涡流结构导致冷却剂流难以正确覆盖。这项工作旨在在端壁上全面布置薄膜冷却孔，以提高 LE 区域和叶片-PS 结区域的冷却剂效率。

设计/方法/方法

端壁膜孔按四孔构造模式分组。研究了三种排列组的方法：基于压力场、流线或传热场。在正确验证湍流模型后，使用 k-ω SST 模型进行计算分析。

发现

通过以四孔模式聚集薄膜冷却孔，冷却剂流的喷射更强。四孔构造模式还提高了“坚韧”区域的局部冷却剂覆盖率，例如 PS 和端壁的连接区域。基于流线分布的布置可以有效提高冷却剂覆盖率，基于传热分布（HTD）的布置具有减少端壁高温区域的好处。

原创性/价值

考虑到不同薄膜冷却孔的相互作用，提出了一种全尺寸端壁薄膜冷却设计。提供了全面的模型验证和网格独立性研究。端壁上的冷却孔图案设计为四孔结构图案，结合多种布置选择，即压力、传热和流线分布。