Numerical study of cooling performance and flow characteristics of film hole-broken rib composite structure with squealer tip

IF 4.9 2区工程技术 Q1 ENGINEERING, MECHANICAL International Journal of Thermal Sciences Pub Date : 2024-06-08 DOI:10.1016/j.ijthermalsci.2024.109211

Zhen Xiang , Shaohua Han , Shizhen Qi , Yibin Jia , Tairan Guo , Na An , Qilong Liu , Tianyi Huo , Jiangjiang Xing , Runsheng Zhang , Leping Zhou , Li Li , Hui Zhang , Xiaoze Du

{"title":"Numerical study of cooling performance and flow characteristics of film hole-broken rib composite structure with squealer tip","authors":"Zhen Xiang , Shaohua Han , Shizhen Qi , Yibin Jia , Tairan Guo , Na An , Qilong Liu , Tianyi Huo , Jiangjiang Xing , Runsheng Zhang , Leping Zhou , Li Li , Hui Zhang , Xiaoze Du","doi":"10.1016/j.ijthermalsci.2024.109211","DOIUrl":null,"url":null,"abstract":"<div><p>The gas turbine blade tip might face substantial heat loads because of leakage flow between the blades and the casing. For blade tip cooling, a composite cooling structure with film holes and broken ribs is first used on GE-E<sup>3</sup> blade in this work. The flow and cooling characteristics of the innovative structure are studied by numerical simulation under various blowing ratio (BR) conditions. Meanwhile, the impact of modifying both the rib angle and the rib height on the adiabatic film cooling effectiveness (AFCE) at the tip of the squealer is analyzed. According to the results, adding rib structures to the squealer tip can effectively regulate the paths of cavity vortices and kidney-shaped vortex pairs (KVP) at the tip. As a result, the averaged AFCE at the blade tip is improved. The notch pressure-side broken rib structure has good aerothermal performance, and the highest AFCE at BRs of 0.50, 1.00, and 1.50 basically occur under the “R60-100 %” condition (R60 refers to the rib structure of 60°, and 100 % is the ratio of rib height to notch depth), and the corresponding AFCE are 27.71 %, 26.00 %, and 32.47 % higher than those of the no-rib case, respectively. The corresponding AFCE increased by 27.71 %, 26.52 %, and 32.47 %, respectively, compared to the no-rib condition. The highest AFCE at a BR of 1.50 occurs at “R75-70 %“, which is a 38.20 % increase in AFCE compared to the no rib case. The improvement in AFCE is due to the difference in the flow of the cooling jets, which are subject to cavity vortices at different BRs. The analysis shows that the addition of ribs disrupts the formation of KVPs and weakens the influence of the cavity vortex, thus reducing the low AFCE region at the lower end of the tip groove and increasing the AFCE. However, due to the blocking effect of the ribs, the pressure loss at the blade tip is elevated. The proposed blade tip cooling structure is expected to provide new ideas for the next generation of advanced gas turbine cooling designs.</p></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Thermal Sciences","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1290072924003338","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}

引用次数: 0

Abstract

The gas turbine blade tip might face substantial heat loads because of leakage flow between the blades and the casing. For blade tip cooling, a composite cooling structure with film holes and broken ribs is first used on GE-E³ blade in this work. The flow and cooling characteristics of the innovative structure are studied by numerical simulation under various blowing ratio (BR) conditions. Meanwhile, the impact of modifying both the rib angle and the rib height on the adiabatic film cooling effectiveness (AFCE) at the tip of the squealer is analyzed. According to the results, adding rib structures to the squealer tip can effectively regulate the paths of cavity vortices and kidney-shaped vortex pairs (KVP) at the tip. As a result, the averaged AFCE at the blade tip is improved. The notch pressure-side broken rib structure has good aerothermal performance, and the highest AFCE at BRs of 0.50, 1.00, and 1.50 basically occur under the “R60-100 %” condition (R60 refers to the rib structure of 60°, and 100 % is the ratio of rib height to notch depth), and the corresponding AFCE are 27.71 %, 26.00 %, and 32.47 % higher than those of the no-rib case, respectively. The corresponding AFCE increased by 27.71 %, 26.52 %, and 32.47 %, respectively, compared to the no-rib condition. The highest AFCE at a BR of 1.50 occurs at “R75-70 %“, which is a 38.20 % increase in AFCE compared to the no rib case. The improvement in AFCE is due to the difference in the flow of the cooling jets, which are subject to cavity vortices at different BRs. The analysis shows that the addition of ribs disrupts the formation of KVPs and weakens the influence of the cavity vortex, thus reducing the low AFCE region at the lower end of the tip groove and increasing the AFCE. However, due to the blocking effect of the ribs, the pressure loss at the blade tip is elevated. The proposed blade tip cooling structure is expected to provide new ideas for the next generation of advanced gas turbine cooling designs.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

带尖啸器的膜孔-断肋复合结构冷却性能和流动特性的数值研究

由于叶片和机壳之间存在泄漏流，燃气轮机叶尖可能面临巨大的热负荷。为了冷却叶尖，本研究首次在 GE-E3 叶片上使用了一种带有薄膜孔和断裂肋片的复合冷却结构。通过数值模拟研究了创新结构在不同吹风比（BR）条件下的流动和冷却特性。同时，分析了改变肋片角度和肋片高度对叶尖绝热膜冷却效果（AFCE）的影响。结果表明，在尖叫器顶端增加肋条结构可以有效调节顶端空腔涡和肾形涡对（KVP）的路径。因此，叶尖的平均 AFCE 得到了改善。缺口压力侧断肋结构具有良好的气动热性能，BR 值为 0.50、1.00 和 1.50 时的最高 AFCE 基本上出现在 "R60-100%"条件下（R60 指 60° 的肋条结构，100% 是肋条高度与缺口深度之比），相应的 AFCE 分别比无肋条情况下的 AFCE 高 27.71%、26.00% 和 32.47%。与无肋条情况相比，相应的 AFCE 分别增加了 27.71 %、26.52 % 和 32.47 %。在 BR 值为 1.50 时，"R75-70 %"的 AFCE 最高，与无肋条情况相比，AFCE 增加了 38.20 %。AFCE 的提高是由于冷却喷流的流动性不同造成的，在不同的 BR 下，冷却喷流会受到空腔涡流的影响。分析表明，增加肋片会破坏 KVP 的形成，削弱空腔漩涡的影响，从而减少尖端凹槽下端的低 AFCE 区域，提高 AFCE。然而，由于肋片的阻挡作用，叶尖的压力损失会升高。所提出的叶尖冷却结构有望为下一代先进的燃气轮机冷却设计提供新思路。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

International Journal of Thermal Sciences 工程技术-工程：机械

CiteScore

8.10

自引率

11.10%

发文量

531

审稿时长

55 days

期刊介绍： The International Journal of Thermal Sciences is a journal devoted to the publication of fundamental studies on the physics of transfer processes in general, with an emphasis on thermal aspects and also applied research on various processes, energy systems and the environment. Articles are published in English and French, and are subject to peer review. The fundamental subjects considered within the scope of the journal are: * Heat and relevant mass transfer at all scales (nano, micro and macro) and in all types of material (heterogeneous, composites, biological,...) and fluid flow * Forced, natural or mixed convection in reactive or non-reactive media * Single or multi–phase fluid flow with or without phase change * Near–and far–field radiative heat transfer * Combined modes of heat transfer in complex systems (for example, plasmas, biological, geological,...) * Multiscale modelling The applied research topics include: * Heat exchangers, heat pipes, cooling processes * Transport phenomena taking place in industrial processes (chemical, food and agricultural, metallurgical, space and aeronautical, automobile industries) * Nano–and micro–technology for energy, space, biosystems and devices * Heat transport analysis in advanced systems * Impact of energy–related processes on environment, and emerging energy systems The study of thermophysical properties of materials and fluids, thermal measurement techniques, inverse methods, and the developments of experimental methods are within the scope of the International Journal of Thermal Sciences which also covers the modelling, and numerical methods applied to thermal transfer.