Film Cooling Effectiveness and Heat Transfer of Rectangular-Shaped Film Cooling Holes

Rhee, Dong-Ho; Lee, Youn Seok; Cho, Hyung Hee

doi:10.1115/gt2002-30168

Cited by 17 publications

(26 citation statements)

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“…Figure 6 shows the cooling effectiveness from different models. Basically, the standard k-ε, RNG, and RSM models give very similar results: The cooling effectiveness differs only by 0.02, which is slightly higher than the test data in [33]. However, the k-ω and SST give results significantly deviating from the former group; the difference of cooling effectiveness can be as large as 0.2.…”

Section: Effect Of Turbulence Modelssupporting

confidence: 50%

Effects of Various Modeling Schemes on Mist Film Cooling Simulation

Wang

2007

Journal of Heat Transfer

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Numerical simulation is performed in this study to explore filmcooling enhancement by injecting mist into the cooling air with a focus on investigating the effect of various modeling schemes on the simulation results. The effect of turbulence models, dispersed-phase modeling, inclusion of different forces (Saffman, thermophoresis, and Brownian), trajectory tracking, and mist injection scheme is studied. The effect of flow inlet boundary conditions (with/without air supply plenum), inlet turbulence intensity, and the near-wall grid density on simulation results is also included. Using a 2-D slot film cooling simulation with a fixed blowing angle and blowing ratio shows a 2% mist injected into the cooling air can increase the cooling effectiveness about 45%. The RNG k-ε model, RSM and the standard k-ε turbulence model with the enhanced wall treatment produce consistent and reasonable results while the turbulence dispersion has a significant effect on mist film cooling through the stochastic trajectory calculation. The thermophoretic force slightly increases the cooling effectiveness, but the effect of Brownian force and Saffman lift is imperceptible. The cooling performance is affected negatively by the plenum in this study, which alters the velocity profile and turbulence intensity at the jet exit plane. The results of this paper can serve as the qualification reference for future more complicated studies including 3-D cooling holes, different blowing ratios, various density ratios, and rotational effect.

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Section: Effect Of Turbulence Modelssupporting

confidence: 50%

Effects of Various Modeling Schemes on Mist Film Cooling Simulation

Wang

2007

Journal of Heat Transfer

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“…There are a lot of published papers that used heat transfer and film cooling effectiveness equations, and in this paper, the equations of Rhee et al [24] will be used. In general, heat transfer to a film-cooled surface is expressed as follows:…”

Section: Heat Transfer Coefficient and Film Cooling Effectiveness Equmentioning

confidence: 99%

“…This decreases the momentum of the jet and reduces penetration into the mainstream. Rhee et al [24] conducted an experimental study to measure the local film cooling effectiveness, and the heat transfer coefficient for four different cooling hole shapes such as a straight rectangular hole, a rectangular hole with laterally expanded exit, a circular hole and a two-dimensional slot is tested. The results showed that the rectangular holes provide better performance than the cylindrical holes.…”

Section: A Review Of Studies On Heat Transfer Coefficientmentioning

confidence: 99%

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CFD Simulations of Film Cooling Effectiveness and Heat Transfer for Annular Film Hole

Abdala

Elwekeel

2016

Arab J Sci Eng

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The increasing turbine entry temperature has placed demands for improvements in engine cooling, and the work described in this paper is the development of a new film cooling configuration to meet this demand. In this study, numerical simulations were performed to predict the improvement in film cooling performance with novel film hole called an annular film hole. The film cooling performance parameters such as heat transfer coefficient (h), film cooling effectiveness (η) and the net heat flux reduction (NHFR) over flat plate were investigated and compared with other configurations. Velocity profiles, pressure coefficient and turbulence kinetic energy contours were discussed. Four mass flow rates of secondary flow fluid were used to investigate the effects of film coolant velocity on the film cooling performance behavior. Results indicate that an annular film hole gives high film effectiveness, low heat transfer coefficient and higher NHFR compared to rectangular and circular film holes. The average values of laterally averaged film cooling effectiveness of the annular film hole increased to 106 and 328.5 % compared with the rectangular and circular film holes at moderate flow rate, respectively. This difference is attributable to decreasing the jet vertical velocity component in a case of the annular hole. Also the low and high heat transfer coefficient regions were described for annular hole in detail. B Antar M. M. Abdala

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“…Eckert et al studied the differences in the wall temperatures inside the cooling holes and the direction changes of the cooling fluid [3][4][5][6][7][8]. Rhee et al suggested a rectangular-shaped channel for good cooling performance under low turbulence [9]. In addition, Sunden et al proposed several cooling techniques to protect the blade tips from local thermal stress and high temperature [10].…”

Section: Introductionmentioning

confidence: 98%

Development of a perpendicular vibration-induced electrical discharge machining process for fabrication of partially wavy inner structures

et al. 2016

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Heat transfer enhancement is an important issue in energy systems. To improve the efficiency of a cooling channel used inside injection molds, turbine blades, and high-temperature devices, channels with various shapes, such as wavy, elliptical, and twisted, have been studied. A cooling channel with a partially wavy inner structure has shown outstanding cooling performance despite a small increase in friction factor. However, generating a partially wavy inner structure inside a channel through conventional machining processes is not easy. To address this problem, we developed a new process called Perpendicular vibration-induced electrical discharge machining (PV-EDM). A specific electrode and one-and random-directional vibrating devices controlled by a pneumatic load were designed for the PV-EDM process. Experimental results showed that local shaping on the inner wall of a channel is possible, which confirmed the possibility of application of this process to actual industrial problems.

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Film Cooling Effectiveness and Heat Transfer of Rectangular-Shaped Film Cooling Holes

Cited by 17 publications

References 0 publications

Effects of Various Modeling Schemes on Mist Film Cooling Simulation

Effects of Various Modeling Schemes on Mist Film Cooling Simulation

CFD Simulations of Film Cooling Effectiveness and Heat Transfer for Annular Film Hole

Development of a perpendicular vibration-induced electrical discharge machining process for fabrication of partially wavy inner structures

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