{"title":"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","authors":"S. Liang, †. R.L.Dong, W. W. Xu, Y. Q. Wei","doi":"10.47176/jafm.17.6.2251","DOIUrl":null,"url":null,"abstract":"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.","PeriodicalId":49041,"journal":{"name":"Journal of Applied Fluid Mechanics","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Numerical Analysis of Film Cooling Flow Dynamics and Thermodynamics for Perfect and Imperfect Cooling Holes\",\"authors\":\"S. Liang, †. R.L.Dong, W. W. Xu, Y. Q. Wei\",\"doi\":\"10.47176/jafm.17.6.2251\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"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.\",\"PeriodicalId\":49041,\"journal\":{\"name\":\"Journal of Applied Fluid Mechanics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2024-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Applied Fluid Mechanics\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://doi.org/10.47176/jafm.17.6.2251\",\"RegionNum\":4,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Fluid Mechanics","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.47176/jafm.17.6.2251","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MECHANICS","Score":null,"Total":0}
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.
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) .