Heat Transfer and Film Cooling Following Normal Injection Through a Round Hole

Eriksen, V. L.; Goldstein, R. J.

doi:10.1115/1.3445854

Cited by 11 publications

(6 citation statements)

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“…The film cooling technique is an effective approach to protect the advanced gas turbine airfoils [6][7][8]. In this process, cooling gas passes through the internal cooling channels and emerges from the film holes to create a blanket of thin film over the outer surface of the airfoil thus preventing the direct contact of the hot gases and the coverage surfaces.…”

Section: Introductionmentioning

confidence: 99%

Effects of Diffusion Film Hole Exit Area on the Film Cooling Effectiveness

Fan

Taslim

2022

International Journal of Rotating Machinery

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One popular method for the protection of gas turbines' hot sections from high-temperature combustor gases is film cooling. Substantial amounts of research have been conducted to accomplish this task with the minimum cooling flow, maximum surface coverage, and minimal aerodynamic inefficiencies or structural penalties. In this study, a combined experimental and numerical investigation was conducted on three selected film-cooling hole geometries. These geometries were designed with the same initial metering (feed) section, a cylindrical hole of 30 °inclination angle, followed by three different forward expansion section geometries. The expansion sections had a 7 °laid-back angle and a 17 °expansion angle in each lateral direction. However, different interior corner radii were used to blend the metering hole to the exit area, creating three different expansion geometries with almost the same exit areas. In practice, this variation in expansion geometry could represent manufacturing faults or tolerances in laser drilling of the film holes. This study shows that the variations in film-cooling effectiveness are not significant even though the expansion geometries are significantly different. The Pressure Sensitive Paint (PSP) technique was used to obtain the detailed distribution of film-cooling effectiveness on the surface area downstream of these film holes. Adiabatic film cooling effectiveness was measured at blowing ratios of 0.5, 1.0, and 2.0. CFD models of these film holes were also run, and the results were compared with the test data. The major conclusions of this study were that these proposed new geometries produced higher film effectiveness than the conventional 7 °-7 °-7 °diffusion film holes, for the same exit area, the expansion section geometry of the film holes did not have a significant effect on the film coverage, and the numerical results were in good agreement with the test data.

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Section: Introductionmentioning

confidence: 99%

Effects of Diffusion Film Hole Exit Area on the Film Cooling Effectiveness

Fan

Taslim

2022

International Journal of Rotating Machinery

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“…To go over the details of each study is well beyond the allotted space in this manuscript. We, however, would like to refer the reader to the work of pioneers such as Goldstein et al [1], Eriksen and Goldstein [2], and Pedersen et al [3] in this field who investigated the effects of main parameters such as hole geometry, density ratio, and blowing ratio on three-dimensional film cooling. Bogard et al [4] and Sen et al [5] reported adiabatic film cooling effectiveness values and heat transfer coefficients downstream of compound angle holes.…”

Section: Introductionmentioning

confidence: 99%

Experimental Film Cooling Effectiveness of Three-Hole-Branch Circular Holes

Fan

Taslim

2021

International Journal of Rotating Machinery

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A three-hole-branch geometry for film cooling is proposed. Each branch is made up of a streamwise 30°-angled circular hole with a circular hole of the same diameter on each side of it. These three holes share the same inlet area on the coolant supply side. Three side hole inclination angles of 30°, 37.5°, and 45° and three branch angles (the angle between the main and side holes) generated nine configurations that were tested for four blowing ratios of 0.5, 1, 1.5, and 2. To their benefits, these straight-through circular holes could easily be laser drilled on the airfoils or other gas turbine hot section surfaces. For comparative evaluation of these film hole geometries, the commonly used 7°-7°-7° diffusion hole geometry with the same inlet hole diameter was tested as a baseline under otherwise identical conditions. The pressure-sensitive paint (PSP) technique was utilized to test these geometries for their film cooling effectiveness. Depending on the branch geometry, for the same amount of coolant, some configurations were found to be superior to the baseline case for stream- or spanwise film cooling distributions while for the steeper side hole angles, these branched holes did not perform as well as the baseline case. The main conclusion is that the three holes with the same inclination angle of 30° exhibited the best film cooling effectiveness performance including the baseline geometry.

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“…The effects of injection geometry and injection ratio have been experimentally investigated by a number of workers. Ramsey and Goldstein (1971), Eriksen and Goldstein (1971), Eriksen and Goldstein (1974), investigated the effect of M and ao on jet trajectory and spread. Kruse and Metzinger (1984) did a systematic study on the effect of M, a o and p/d on the spanwise averaged effectiveness (n).…”

Section: Introductionmentioning

confidence: 99%

Prediction of Heat Transfer Characteristics for Discrete Hole Film Cooling for Turbine Blade Applications

Tafti

Yavuzkurt

1989

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration

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A two-dimensional (2-D) injection model is used with a 2-D low Reynold’s number k-ε model boundary layer code. The three-dimensional effects of the discrete hole injection process is introduced in the 2-D prediction scheme through an “entrainment fraction” (T). An established correlation between T and the injection parameters obtained in a previous paper is used to predict the film cooling effectiveness (η̄) and heat transfer coefficients for multirow injection, injection into a laminar boundary layer and finally injection on convex curved surfaces. Predictions of η̄ are in good agreement with experimental data for most of the cases tested. Predictions of Stanton numbers defined by St(0) and St(1) are good for low injection ratios (M) but as M increases the values are underpredicted. In spite of some shortcomings, in the authors’ opinion the present 2-D prediction scheme is one of the most comprehensive developed so far. It is seen that the entrainment fraction T is quite universal in its application to 2-D predictions of the discrete hole film cooling process.

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Heat Transfer and Film Cooling Following Normal Injection Through a Round Hole

Cited by 11 publications

References 0 publications

Effects of Diffusion Film Hole Exit Area on the Film Cooling Effectiveness

Effects of Diffusion Film Hole Exit Area on the Film Cooling Effectiveness

Experimental Film Cooling Effectiveness of Three-Hole-Branch Circular Holes

Prediction of Heat Transfer Characteristics for Discrete Hole Film Cooling for Turbine Blade Applications

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