Pin-fin cooling has long been a crucial technique employed in gas turbine blades to manage the extreme thermal conditions experienced during operation. While numerous studies have investigated the heat transfer characteristics of different pin–fin configurations, the substantial impact of the endwall of the cooling channel on the heat transfer capability of turbine blades has not received adequate attention or thorough investigation. This research paper focuses on studying the influence of a novel geometry, termed C-shaped-recessed endwall, on pin–fin cooling channels in gas turbine blades. The primary objective of this investigation is to analyze the vortex formation and its impact on heat transfer characteristics within the cooling system. The study involved testing five different pin–fin arrays with C-shaped-recessed endwalls inserted between them, spanning a Reynolds number range of 7400 to 36000. The results show that with reference geometrical values, the new geometry increases the Heat Transfer Efficiency Index (HTEI) by 36.53 % compared to the flat endwall at Re = 29000. Higher heat transfer capacities were achieved by manipulating the C-shaped-recessed endwall heights and width of indentations, and the peak HTEI recorded an increase of 49.75 % at Re = 29000 compared to the flat endwall. The findings from this study underscore the potential of the C-shaped-recessed endwall geometry to improve the heat transfer capability of pin-fins by optimizing endwall configurations.

中文翻译：

---

燃气轮机叶片内冷通道C形凹端壁针翅片传热特性数值研究

长期以来，针翅式冷却一直是燃气轮机叶片采用的一项关键技术，用于管理运行过程中遇到的极端热条件。虽然大量研究调查了不同针翅结构的传热特性，但冷却通道端壁对涡轮叶片传热能力的实质性影响尚未得到足够的关注或彻底的研究。本研究论文重点研究一种新型几何形状（称为 C 形凹进端壁）对燃气轮机叶片中针翅式冷却通道的影响。这项研究的主要目的是分析涡流的形成及其对冷却系统内传热特性的影响。该研究涉及测试五种不同的针翅阵列，其间插入了 C 形凹进端壁，雷诺数范围为 7400 至 36000。结果表明，根据参考几何值，新的几何形状提高了传热效率指数（与 Re = 29000 时的平坦端壁相比，HTEI）提高了 36.53 %。通过控制 C 形凹进端壁高度和凹痕宽度实现了更高的传热能力，并且在 Re = 29000 时峰值 HTEI 增加了 49.75 %与平坦端壁相比。这项研究的结果强调了 C 形凹进端壁几何形状通过优化端壁配置来提高针翅片传热能力的潜力。