Abstract This paper aims to provide a novel enhanced heat transfer method for the internal tip surface of a U bend channel of relevance for a gas turbine rotor blade. The DWVGs (delta-winglet vortex generators) pair is arranged at multiple locations on the tip surface. Two types of vortex generators are studied, including common-flow-up and common-flow-down configurations. The inlet channel Reynolds number varies from 10,000 to 50,000. The topological analysis method is used to determine the formation and evolution of the vortices and to better understand the mechanism of the heat transfer enhancement. Results of skin-friction lines, topological portrait, Nusselt number, friction factor, thermal performance are included. The results show that due to the interaction among the vortices surrounding the vortex generators, the DWVGs pair in common-flow-up configuration has a slight heat transfer improvement, and is not sensitive to the tip location. However, the DWVGs pair in common-flow-down configuration placed at the downstream of the tip surface improved the heat transfer significantly as the induced vortices between the turbulator pairs effectively reduce the thickness of the boundary layer. Compared with the smooth U bend channel, the optimal design shows that the heat transfer and overall thermal performance can be increased by up to 7.4% and 6.8%, respectively. This study elaborates the flow and heat transfer processes from the perspective of topology, which is helpful in the design of cooling procedures of turbine blades.

中文翻译：

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不同三角翼涡发生器布置的燃气轮机叶片内叶尖涡结构拓扑及传热研究

摘要 本文旨在为与燃气轮机转子叶片相关的 U 形弯曲通道的内部尖端表面提供一种新的增强传热方法。DWVG（三角翼涡流发生器）对布置在尖端表面的多个位置。研究了两种类型的涡流发生器，包括共同向上流动和共同向下流动配置。入口通道雷诺数从 10,000 到 50,000 不等。拓扑分析方法用于确定涡流的形成和演化，更好地理解传热增强的机制。包括皮肤摩擦线、拓扑图、努塞尔数、摩擦系数、热性能的结果。结果表明，由于涡流发生器周围涡流之间的相互作用，共同向上流动配置中的 DWVG 对具有轻微的传热改进，并且对尖端位置不敏感。然而，放置在尖端表面下游的共同向下流动配置的 DWVGs 对显着改善了传热，因为湍流器对之间的诱导涡流有效地降低了边界层的厚度。与光滑的 U 形弯道相比，优化设计表明传热和整体热性能可分别提高 7.4% 和 6.8%。本研究从拓扑学的角度阐述了流动和传热过程，有助于涡轮叶片冷却程序的设计。放置在尖端表面下游的共同向下流动配置的 DWVGs 对显着改善了传热，因为湍流器对之间的诱导涡流有效地降低了边界层的厚度。与光滑的 U 形弯道相比，优化设计表明传热和整体热性能可分别提高 7.4% 和 6.8%。本研究从拓扑学的角度阐述了流动和传热过程，有助于涡轮叶片冷却程序的设计。放置在尖端表面下游的共同向下流动配置的 DWVGs 对显着改善了传热，因为湍流器对之间的诱导涡流有效地降低了边界层的厚度。与光滑的 U 形弯道相比，优化设计表明传热和整体热性能可分别提高 7.4% 和 6.8%。本研究从拓扑学的角度阐述了流动和传热过程，有助于涡轮叶片冷却程序的设计。优化设计表明，传热和整体热性能可分别提高 7.4% 和 6.8%。本研究从拓扑学的角度阐述了流动和传热过程，有助于涡轮叶片冷却程序的设计。优化设计表明，传热和整体热性能可分别提高 7.4% 和 6.8%。本研究从拓扑学的角度阐述了流动和传热过程，有助于涡轮叶片冷却程序的设计。