完美和不完美冷却孔的薄膜冷却流动力学和热力学数值分析

IF 1.1 4区工程技术 Q4 MECHANICS

Journal of Applied Fluid Mechanics Pub Date : 2024-06-01 DOI:10.47176/jafm.17.6.2251

S. Liang, †. R.L.Dong, W. W. Xu, Y. Q. Wei

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引用次数: 0

摘要

薄膜冷却可保护高温部件，并通过主流流与注入的冷却剂之间的相互作用产生复杂的涡流结构。此外，涂覆隔热涂层的过程会产生不完美的冷却孔。为了研究流场涡流结构和孔缺陷的影响，我们对平板上单排排列的倾斜完美孔和不完美孔这两种几何配置进行了数值模拟研究。采用 k-epsilon 湍流模型分析了不同吹气比和缺陷位置对流场结构和冷却效率的影响，涡流动力学提供了解释性见解。随着吹气比的增大，与完美孔洞相关的肾涡逐渐脱离壁面，从而降低了薄膜冷却效率。肾型漩涡源于主流和撞击射流之间的剪切相互作用，主要受漩涡拉伸分量的影响。不完善的孔会影响肾涡的分布状态，在 IT4 缺陷位置观察到的卷曲现象会减弱。因此，在孔的近端附近，薄膜冷却效果明显增强。

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Numerical Analysis of Film Cooling Flow Dynamics and Thermodynamics for Perfect and Imperfect Cooling Holes

Film cooling protects high-temperature components and generates complex vortex structures through the interaction between the mainstream flow and the injected coolant. Additionally, the process of applying thermal barrier coatings introduces imperfect cooling holes. A numerical simulation study is conducted on two geometric configurations: inclined perfect and imperfect holes arranged in a single row on a flat plate to investigate the effects of flow field vortex structures and hole imperfections. The k-epsilon turbulent model is employed to analyse the impact of varying blowing ratios and defect positions on flow field structure and cooling efficiency, with vortex dynamics providing explanatory insights. As the blowing ratio increases, the kidney vortex associated with the perfect holes progressively detaches from the wall, reducing film cooling efficiency. The kidney vortex originates from the shear interaction between the mainstream and the impinging jet, predominantly influenced by the vortex stretching component. Imperfect holes influence the distribution state of the kidney vortex, with weakened roll-up phenomena observed at the IT4 defect location. Consequently, a noticeable enhancement in film cooling effectiveness is achieved near the proximal end of the hole.

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来源期刊

Journal of Applied Fluid Mechanics THERMODYNAMICS-MECHANICS

CiteScore

2.00

自引率

20.00%

发文量

138

审稿时长

>12 weeks

期刊介绍： The Journal of Applied Fluid Mechanics (JAFM) is an international, peer-reviewed journal which covers a wide range of theoretical, numerical and experimental aspects in fluid mechanics. The emphasis is on the applications in different engineering fields rather than on pure mathematical or physical aspects in fluid mechanics. Although many high quality journals pertaining to different aspects of fluid mechanics presently exist, research in the field is rapidly escalating. The motivation for this new fluid mechanics journal is driven by the following points: (1) there is a need to have an e-journal accessible to all fluid mechanics researchers, (2) scientists from third- world countries need a venue that does not incur publication costs, (3) quality papers deserve rapid and fast publication through an efficient peer review process, and (4) an outlet is needed for rapid dissemination of fluid mechanics conferences held in Asian countries. Pertaining to this latter point, there presently exist some excellent conferences devoted to the promotion of fluid mechanics in the region such as the Asian Congress of Fluid Mechanics which began in 1980 and nominally takes place in one of the Asian countries every two years. We hope that the proposed journal provides and additional impetus for promoting applied fluids research and associated activities in this continent. The journal is under the umbrella of the Physics Society of Iran with the collaboration of Isfahan University of Technology (IUT) .