Film Cooling of a Gas Turbine Blade

Ito, S.; Goldstein, R. J.; Eckert, E. R. G.

doi:10.1115/1.3446382

Cited by 164 publications

(61 citation statements)

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“…The verification of such statement may be given when the results of studies that have investigated the effect of curvature and such, present in airfoil types of configuration, are reviewed, e.g. Mayle et al [38], Ito et al [39] and Davidson et al [40].…”

Section: Computational Fluid Dynamics Studiesmentioning

confidence: 99%

On Film Cooling of Turbine Guide Vanes : From Experiments and CFD-Simulations to Correlation Development

Najafabadi¹

2015

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To achieve high thermal efficiency in modern gas turbines, the turbine-inlet temperature has to be increased. In response to such requisites and to prevent thermal failure of the components exposed to hot gas streams, the use of different cooling techniques, including film cooling, is essential. Finding an optimum film cooling design has become a challenge as it is influenced by a large number of flow and geometrical parameters. This study is dedicated to some important aspects of film cooling of a turbine guide vane and consists of three parts. The first part is associated with an experimental investigation of the suction and pressure side cooling by means of a transient IR-Thermography technique under engine representative conditions. It is shown that the overall film cooling performance of the suction side can be improved by adding showerhead cooling if fan-shaped holes are used, while cylindrical holes may not necessarily benefit from a showerhead. According to the findings, investigation of an optimum cooling design for the suction side is not only a function of hole shape, blowing ratio, state of approaching flow, etc., but is also highly dependent on the presence/absence of showerhead cooling as well as the number of cooling rows. In this regard, it is also discussed that the combined effect of the adiabatic film effectiveness (AFE) and the heat transfer coefficient (HTC) should be considered in such study. As for the pressure side cooling, it is found that either the showerhead or a single row of cylindrical cooling holes can enhance the HTC substantially, whereas a combination of the two or using fan-shaped holes indicates considerably lower HTC. An important conclusion is that adding more than one cooling row will not augment the HTC and will even decrease it under certain circumstances. In the second part, computational fluid dynamics (CFD) investigations have shown that film cooling holes subjected to higher flow acceleration will maintain a higher level of AFE. Although this was found to be valid for both suction and pressure side, due to an overall lower acceleration for the pressure side, a lower AFE was achieved. Moreover, the CFD results indicate that fan-shaped holes with low area ratio (dictated by design constraints for medium-size gas turbines), suffer from cooling jet separation and hence reduction in AFE for blowing ratios above unity. Verification of these conclusions by experiments suggests that CFD can be used more extensively, e.g. for parametric studies. The last part deals with method development for deriving correlations based on experimental data to support engineers in the design stage. The proposed method and the ultimate correlation model could successfully correlate the laterally averaged AFE to the downstream distance, the blowing ratio and the local pressure coefficient representing the effect of approaching flow. The applicability of the method has been examined and the high level of predictability of the final model demonstrates its suitability to be used for design purposes...

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Section: Computational Fluid Dynamics Studiesmentioning

confidence: 99%

On Film Cooling of Turbine Guide Vanes : From Experiments and CFD-Simulations to Correlation Development

Najafabadi¹

2015

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“…The Heat Transfer Laboratory has investigated film cooling effectiveness using the foreign gas injection method through ondtwo rows of film cooling holes on convex/concave surfaces and turbine blades (Schwan andGoldstein, 1988 andIto, Goldstein andEckert, 1978). Results show that the blade surface curvature influences the f i l m cooling effectiveness particularly in the vicinity of the injection holes, with higher effectiveness on the convex surface, lower on the concave surface, as compared to a flat plate case.…”

Section: Surface Measurementsmentioning

confidence: 99%

Proceedings of the 1999 Advanced Turbine Systems Annual Program Review Meeting

2000

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ForewordThe U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Office of Fossil Energy, held its Second Annual Advanced Turbine Systems Program Review on November 9-11, 1994, in Arlington, Virginia. The goals of this eight-year program are to develop cleaner, more efficient, and less expensive gas turbine systems for utility and industrial electric power generation, cogeneration, and mechanical drive units. Projects are funded jointly by the office of Fossil Energy and private industry.During the three-day meeting, presentations on energy policy issues were delivered by representatives of regulatory, industry, and research institutions; program overviews and technical reviews were given by contractors; and on-going and proposed future projects sponsored by university and industry were presented and displayed at the poster session. Panel discussions on distributed power and Advanced Gas Systems Research (AGTSR) education provided a forum for interactive dialog and exchange of ideas. Exhibitors at the conference included the U.S. Department of Energy; Solar Turbines, Incorporated; Westinghouse Electric Corporation; Allison Engine Company; and General Electric.This proceedings contains copies of the majority of the papers and posters presented during the sessions in the order listed on the agenda.William P. Parks, Jr. Acting Director, Industrial Energy Efficiency Division Advanced Turbine Systems Office of Industrial Technologies DISCLAIlWRThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, qr process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product; process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recornmendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. V INTRODUCTIONThese proceedings summarize the annual activities of the Advanced Turbine System (ATS) Program. The objective of the program is to develop more efficient gas turbine systems for both, utility and industrial power generation (including cogeneration). The program is developing base-load power systems for commercial offering in the year 2000. Although the target market is natural gas, advanced turbine systems will be adaptable to coal and biomass fuels. All advanced turbines will exhibit: (1) ultra-high efficiencies, (2) environmentally superiority, and (3) cost competitiveness.The ATS ""Comprehensive Program Plan" outlines an eight-year program, estimated to be $700 million consisting...

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“…Ito et al (1978) found that an increase in coolant-to-mainstream density ratio causes an increase in film effectiveness on both pressure and suction surfaces for a blowing ratio of 1.0. Haas et al (1992) found that their results show the same trends as that of Ito et al (1978). They reported that an increase in coolant density for a low blowing ratio of 0.5 causes a decrease in film effectiveness on the suction surface.…”

Section: Introductionmentioning

confidence: 99%

“…Takeishi et al (1992) compared the film effectiveness values for a stationary cascade with mainstream turbulence intensity under 4% and for a rotor blade using the heat-mass transfer analogy. Ito et al (1978) and Haas et al (1992) studied the effect of coolant density on film effectiveness on turbine blades under low mainstream turbulence levels. Ito et al (1978) found that an increase in coolant-to-mainstream density ratio causes an increase in film effectiveness on both pressure and suction surfaces for a blowing ratio of 1.0.…”

Section: Introductionmentioning

confidence: 99%

“…Ito et al (1978) and Haas et al (1992) studied the effect of coolant density on film effectiveness on turbine blades under low mainstream turbulence levels. Ito et al (1978) found that an increase in coolant-to-mainstream density ratio causes an increase in film effectiveness on both pressure and suction surfaces for a blowing ratio of 1.0. Haas et al (1992) found that their results show the same trends as that of Ito et al (1978).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Detailed Film Cooling Measurements over a Gas Turbine Blade Using a Transient Liquid Crystal Image Technique

Ekkad

Han

et al. 2001

International Journal of Rotating Machinery

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Detailed heat transfer coefficient and film effectiveness distributions over a gas turbine blade with film cooling are obtained using a transient liquid crystal image technique. The test blade has three rows of film holes on the leading edge and two rows each on the pressure and suction sur- for CO2 injection. Results show that film injection promotes earlier laminar-turbulent boundary layer transition on the suction surface and also enhances local heat transfer coefficients (up to 80%) downstream of injection. An increase in coolant blowing ratio produces higher heat transfer coefficients for both coolants. This effect is stronger immediately downstream of injection holes. Film effectiveness is highest at a blowing ratio of 0.8 for air injection and at a blowing ratio of 1.2 for CO2 injection. Such detailed results will help provide insight into the film cooling phenomena on a gas turbine blade.

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Film Cooling of a Gas Turbine Blade

Cited by 164 publications

References 0 publications

On Film Cooling of Turbine Guide Vanes : From Experiments and CFD-Simulations to Correlation Development

On Film Cooling of Turbine Guide Vanes : From Experiments and CFD-Simulations to Correlation Development

Proceedings of the 1999 Advanced Turbine Systems Annual Program Review Meeting

Detailed Film Cooling Measurements over a Gas Turbine Blade Using a Transient Liquid Crystal Image Technique

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