Volume 5C: Heat Transfer最新文献_第5页

LES Study of the Laminar Heat Transfer Augmentation on the Pressure Side of a Turbine Vane Under Freestream Turbulence 自由流湍流条件下涡轮叶片压力侧层流强化换热的LES研究

Volume 5C: Heat Transfer Pub Date : 2018-06-11 DOI: 10.1115/GT2018-77135

Y. Kanani, S. Acharya, F. Ames

{"title":"LES Study of the Laminar Heat Transfer Augmentation on the Pressure Side of a Turbine Vane Under Freestream Turbulence","authors":"Y. Kanani, S. Acharya, F. Ames","doi":"10.1115/GT2018-77135","DOIUrl":"https://doi.org/10.1115/GT2018-77135","url":null,"abstract":"Vane pressure side heat transfer is studied numerically using Large Eddy Simulation (LES) on an aft loaded vane with a large leading edge over a range of turbulence conditions. Numerical simulations are performed in a linear cascade at exit chord Reynolds number of Re = 5.1 × 105 at low (Tu≈0.7%), moderate (Tu≈7.9%) and high (Tu≈12.4%) freestream turbulence with varying length scales as prescribed by the experimental measurements of Varty and Ames (2016). Heat transfer predictions (i.e. Stanton number based on exit condition) on the vane pressure side are in a very good agreement with the experimental measurements and the heat transfer augmentation due to the freestream turbulence is well captured. At Tu≈12.4%, freestream turbulence enhances the Stanton number on the pressure surface without boundary layer transition to turbulence by a maximum of about 50% relative to the low freestream turbulence case (Tu≈0.7%). Higher freestream turbulence generates elongated structures and high-velocity streaks wrapped around the leading edge that contain significant energy. Amplification of the velocity streaks is observed further downstream with max r.m.s of 0.3 near the trailing edge but no transition to turbulence or formation of turbulence spots is observed on the pressure side. The heat transfer augmentation at the higher freestream turbulence is primarily due to the initial amplification of the low-frequency velocity perturbations inside the boundary layer that persist along the entire chord of the airfoil. Stanton numbers appear to scale with the streamwise velocity fluctuations inside the boundary layer. Görtler vortices are not observed for this airfoil geometry.","PeriodicalId":239866,"journal":{"name":"Volume 5C: Heat Transfer","volume":"8 10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128991759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Assessment of External Heat Transfer Modeling of a Laboratory-Scale Combustor Inside a Pressure-Housing Environment 压力壳体环境下实验室规模燃烧器外传热模型的评估

Volume 5C: Heat Transfer Pub Date : 2018-06-11 DOI: 10.1115/GT2018-76579

P. L. Rodrigues, O. Gicquel, N. Darabiha, K. Geigle, R. Vicquelin

{"title":"Assessment of External Heat Transfer Modeling of a Laboratory-Scale Combustor Inside a Pressure-Housing Environment","authors":"P. L. Rodrigues, O. Gicquel, N. Darabiha, K. Geigle, R. Vicquelin","doi":"10.1115/GT2018-76579","DOIUrl":"https://doi.org/10.1115/GT2018-76579","url":null,"abstract":"Many laboratory-scale combustors are equipped with viewing windows to allow for characterization of the reactive flow. Additionally, pressure housing is used in this configuration to study confined pressurized flames. Since the flame characteristics are influenced by heat losses, the prediction of wall temperature fields becomes increasingly necessary to account for conjugate heat transfer in simulations of reactive flows. For configurations similar to this one, the pressure housing makes the use of such computations difficult in the whole system. It is therefore more appropriate to model the external heat transfer beyond the first set of quartz windows. The present study deals with the derivation of such a model which accounts for convective heat transfer from quartz windows external face cooling system, free convection on the quartz windows 2, quartz windows radiative properties, radiative transfer inside the pressure housing and heat conduction through the quartz window. The presence of semi-transparent viewing windows demands additional care in describing its effects in combustor heat transfers. Because this presence is not an issue in industrial-scale combustors with opaque enclosures, it remains hitherto unaddressed in laboratory-scale combustors. After validating the model for the selected setup, the sensitivity of several modeling choices is computed. This enables a simpler expression of the external heat transfer model that can be easily implemented in coupled simulations.","PeriodicalId":239866,"journal":{"name":"Volume 5C: Heat Transfer","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132281011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Effects of Combustor Cooling Features on Nozzle Guide Vane Film Cooling Experiments 燃烧室冷却特性对喷嘴导叶气膜冷却实验的影响

Volume 5C: Heat Transfer Pub Date : 2018-06-11 DOI: 10.1115/GT2018-75249

Nicholas E. Holgate, P. Ireland, E. Romero

{"title":"The Effects of Combustor Cooling Features on Nozzle Guide Vane Film Cooling Experiments","authors":"Nicholas E. Holgate, P. Ireland, E. Romero","doi":"10.1115/GT2018-75249","DOIUrl":"https://doi.org/10.1115/GT2018-75249","url":null,"abstract":"Recent advances in experimental methods have allowed researchers to study nozzle guide vane film cooling in the presence of combustor dilution ports and endwall films. The dilution injection creates nonuniformities in temperature, velocity, and turbulence, and an understanding of the vane film cooling performance is complicated by competing influences. In this study, dilution port temperature profiles have been measured in the absence of vane film cooling and compared to film effectiveness measurements in the presence of both films and dilution, illustrating the effects of the dilution port turbulence on film cooling performance. It is found that dilution port injection can create significant effectiveness benefits at the difficult-to-cool vane stagnation region, due to the more turbulent hot mainstream enhancing the mixing of film coolant jets that have left the airfoil surface.\u0000 Also explored are the implications of endwall film cooling for infrared vane surface temperature measurements. The reduced endwall temperatures reduce the thermal emissions from this surface, so reducing the amount of extraneous radiation reflected from the vane surface where measurements are being made. The results of a detailed calibration show that the maximum local film effectiveness measurement error could be up to 0.05 if this effect were to go unaccounted for.","PeriodicalId":239866,"journal":{"name":"Volume 5C: Heat Transfer","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125214424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Endwall 3D Contouring on Film Cooling Effectiveness of Cylindrical Hole Injections at Different Locations on Vane Endwall 端壁三维轮廓对叶片端壁不同位置圆柱孔注入气膜冷却效果的影响

Volume 5C: Heat Transfer Pub Date : 2018-06-11 DOI: 10.1115/GT2018-76844

Pingting Chen, Hongyu Gao, Xueying Li, Jing Ren, Hongde Jiang

{"title":"Effects of Endwall 3D Contouring on Film Cooling Effectiveness of Cylindrical Hole Injections at Different Locations on Vane Endwall","authors":"Pingting Chen, Hongyu Gao, Xueying Li, Jing Ren, Hongde Jiang","doi":"10.1115/GT2018-76844","DOIUrl":"https://doi.org/10.1115/GT2018-76844","url":null,"abstract":"With the development of gas turbine, the secondary flow loss in vane passage is getting higher. To reduce the strength of secondary flows within vane passage, endwall 3D contouring is an effective design. Endwall 3D contouring can lead to significant changes in the secondary flow vortices, which lead to changes on jet-to-secondary flow interaction and then changes on the film cooling effectiveness. Meanwhile, the geometry configuration of the contoured endwall, such as the rising and falling on the endwall, can also have an impact on film cooling performance. As a result, the film cooling performance on contoured endwall differs from that on flat endwall. Understanding the difference in film cooling characteristics on the contoured endwall and flat endwall may help to make better endwall contouring design and better endwall film cooling arrangement.\u0000 The present experiment compares the film cooling effectiveness of cylindrical hole injections at different locations on 3D contoured endwall versus flat endwall in an NGV (nozzle guide vane) passage. The measurement is performed in a low speed wind tunnel with a F-class annular sector NGV cascade. The cylindrical hole injections are located as 4 different rows at −30% axial chord, 30% axial chord, 50% axial chord and 70% axial chord. Endwall pressure distribution is measured with pressure taps by pressure sensor while film cooling effectiveness is measured using PSP (Pressure Sensitive Paint). Two density ratios with 1.0 and 1.5 and several average blowing ratios are investigated. Effects of endwall contouring, density ratio and blowing ratio on film cooling effectiveness are obtained and the results are presented and explained in this investigation.","PeriodicalId":239866,"journal":{"name":"Volume 5C: Heat Transfer","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133299998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Studies on Cooling Performance of Round Cooling Holes With Various Configurations on a High-Pressure Turbine Vane 高压涡轮叶片不同结构圆孔冷却性能研究

Volume 5C: Heat Transfer Pub Date : 2018-06-11 DOI: 10.1115/GT2018-75439

K. Funazaki, Fumiya Kikuchi, Issei Tashiro, T. Ideta, Yuhi Tanaka

引用次数: 0

Numerical Investigation of Gas Turbine Combustor Liner Film Cooling Slots 燃气轮机燃烧室尾膜冷却槽的数值研究

Volume 5C: Heat Transfer Pub Date : 2018-06-11 DOI: 10.1115/GT2018-75608

Firat Kiyici, A. Topal, Ender Hepkaya, S. Inanli

引用次数: 5