Cooling Performance of an Integrated Impingement and Pin Fin Cooling Configuration

Yamawaki, Shigemichi; Nakamata, Chiyuki; Imai, Ryouji; Matsuno, Shinsuke; Yoshida, Toyoaki; Mimura, Fujio; Kumada, Masaya

doi:10.1115/gt2003-38215

Cited by 18 publications

(7 citation statements)

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“…Quan et al [10] measured the cooling performance of an impingement system combined with pin fins by using infrared technology, and the overall cooling effectiveness was above 0.8. Funazaki et al [11,12], Son, et al [9] and Yamawaki et al [13] investigated the impingement cooling combined with circular pin fins by using transient liquid crystal technology. Their results showed that the wetted-area averaged Nusselt number of pin-fin roughened target plate was lower than flat plate; however the total heat transfer quantity of the pin-fin roughened plate increased by up to 50%, and the maximum pressure loss only increased by 10%.…”

Section: Introductionmentioning

confidence: 99%

Numerical predictions of jet impingement heat transfer on square pin-fin roughened plates

Wan

Rao

Chen

2015

Applied Thermal Engineering

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Section: Introductionmentioning

confidence: 99%

Numerical predictions of jet impingement heat transfer on square pin-fin roughened plates

Wan

Rao

Chen

2015

Applied Thermal Engineering

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“…Different morphology of target surface was carried out for optimal heat transfer performance, such as rib roughened surface [18,19], pin fin [20,21], and other shapes [22]. In 2000, Azad et al [23] studied the heat transfer characteristics of impinging jet with cylindrical dimpled target surface experimentally (Rej = 4850-18,300, ô/D = 0.5).…”

Section: Introductionmentioning

confidence: 99%

Flow and Heat Transfer Characteristics of Single Jet Impinging on Dimpled Surface

Xie¹,

Li²,

Lan³

et al. 2013

Journal of Heat Transfer

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Flow and Heat Transfer Characteristics of Single Jet Impinging on Dimpled SurfaceBased on combined particle image velocimetry (PIV) and numerical simulation, the flow and heat transfer characteristics of a single jet impinging on a dimpled surface for D/ D = 0.318. 0.5. 1.045; ô/D = 0.1, 0.2, 0.3; Rej = 5000. 10.000,23,000, were investigated for the first time. The distance between jet nozzle and plate was fi.xed and equal to H/D = 2. The results show that the flow structures of the single jet impingement with dimpled target surface can be summarized into three typical conceptual flow structures. Particularly, the third flow structure in the form of a large toroidal vortex bound up with the dimple is the result of the centrifugal force of the flow deflection at the stagnation region and spherical centrifugal force of the deep dimple surface. The heat transfer area increases when the dimple relative depth increases. For the cases of D/D = 0.318 and 0.5. the area increasing dominate the heat transfer process, and the average Nusselt number increases with the increasing of dimple relative depth. For the cases with Dy/D = 1.045, the local Nusselt number reduction dominate the heat transfer process, the average Nusselt number decreases with the increasing of dimple relative depth. The average Nusselt number of the Dj/D = 0.318 and 0.5 cases is larger than the baseline case, while those of the DjiD = 1.045 cases are smaller than the baseline case. Furthermore, the correlative expressions of the local Nusselt number, stagnation points Nusselt number and average Nusselt number are obtained.

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“…This is a kind of indication that movement of the wall jet was considerably blocked so that the heat transfer on the target plate somewhat drastically decreased. Furthermore, Yamawaki et al [1] reported that highly dense pin arrangement on the target plate seriously affected the heat transfer beneath the impingement jet. Accordingly, the pins very close to the impingement jet can be attributed to the reduction of heat transfer due to the impingement jet.…”

Section: Internal Heat Transfermentioning

confidence: 99%

“…However, because of the limited amount of the cooling air in consideration of thermal efficiency of gas turbine cycle, the development of much more effective cooling technology of the turbine vanes and blades is indeed indispensable to the achievement of higher TIT gas turbines. Among a number of new cooling technologies proposed so far, the present authors and other groups have been intensively investigating impingement cooling structures integrated with pin-fin cooling and film cooling as shown in Figure 1 [1], which is a conceptual image of this cooling structure. Funazaki et al [4] first proposed a basic configuration of the integrated impingement cooling system, followed by experimental and numerical verifications of the heat transfer enhancement attained inside the proposed concept.…”

Section: Introductionmentioning

confidence: 99%

Extensive Studies on Internal and External Heat Transfer Characteristics of Integrated Impingement Cooling Structures for HP Turbines

Funazaki

Salleh

2008

Volume 4: Heat Transfer, Parts a and B

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This paper deals with experimental and computational studies on internal and external heat transfer characteristics of advanced impingement cooling units combined with pin-fin cooling as well as film cooling, which is called integrated impingement cooling structure. This integrated cooling structure can be employed in the not too distant future as a simple model of quasi-transpiration cooling system for ultra high TIT (Turbine Inlet Temperature) aeroengines or gas turbines. The present study is motivated by the study of Nakamata et al. (2005) who carried out a series of studies on the integrated impingement cooling system. They found that several arrangements of impingement holes and film cooling holes mutually staggered with respect to pins yielded better cooling performance than other non-staggered configurations, although there was no evidence-based explanations shown in their study on the flow physics happening in the cooling models. Therefore, two large-scaled acrylic-resin test models with different arrangements of the impingement and film cooling holes around the pins are made in the present study, emulating the specimens used by Nakamata et al., to evaluate internal and external heat transfer coefficients as well as film effectiveness of the test models. This study accordingly aims at clarification of the reason for the clear distinction in cooling efficiency observed by Nakamata et al. between those two different cooling configurations. The measurement technique employed is a transient method using thermochromic liquid crystal to determine not only heat transfer coefficient but also film effectiveness at the same time. Steady RANS simulation is also executed using ANSYS CFX-10 to acquire detailed information on the flow behaviors and heat transfer characteristics inside and outside the cooling systems. The experimental data, along with the numerical information, reveal that the observed difference in cooling efficiency is can be explained mainly by the difference in internal heat transfer coefficient over the target plate, indicating that the pin arrangement around the impingement jet is an important factor in order to attain higher cooling performance of the proposed integrated impingement cooling system.

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Cooling Performance of an Integrated Impingement and Pin Fin Cooling Configuration

Cited by 18 publications

References 0 publications

Numerical predictions of jet impingement heat transfer on square pin-fin roughened plates

Numerical predictions of jet impingement heat transfer on square pin-fin roughened plates

Flow and Heat Transfer Characteristics of Single Jet Impinging on Dimpled Surface

Extensive Studies on Internal and External Heat Transfer Characteristics of Integrated Impingement Cooling Structures for HP Turbines

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