Effects of upstream ramp on the performance of film cooling

Chen, Shuping P.; Chyu, Minking K.; Shih, Tsan‐Hsing

doi:10.1016/j.ijthermalsci.2010.10.005

Cited by 50 publications

(27 citation statements)

References 14 publications

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“…7 where the curves show recognizable trends in the range of (X/D= 5-30) and the temperature ratio of T c /T g =0. 6 shows best agreement with the experimental study in compression to the other temperature ratios.…”

Section: Resultssupporting

confidence: 84%

“…They found that an increase of the forward expansion angle makes a reduction of film cooling effectiveness and the lateral expansion angle has the biggest impact among the four geometrical variables on the spatially averaged film cooling effectiveness. Chen et al [6] experimentally evaluated the efficiency of the concept of using an upstream ramp to enhance film cooling performance. They concluded that a large ramp angle with a high blowing ratio leads to better film cooling protection than other cases considered.…”

Section: Introductionmentioning

confidence: 99%

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Validation of three dimensional film cooling modeling on convex surface for gas turbine blade

Yusop¹,

Ali²,

Abdullah³

2012

International Communications in Heat and Mass Transfer

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Section: Resultssupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Validation of three dimensional film cooling modeling on convex surface for gas turbine blade

Yusop¹,

Ali²,

Abdullah³

2012

International Communications in Heat and Mass Transfer

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“…In comparison with the case of D0-B0, film coverage length is increased by surface deposition, especially at larger BR=1.5 and 2.0. As discussed by Barigozzi et al [22] and Chen et al [23], the upstream deposition or ramp can uplift mainstream from the wall, and cause an area of low pressure behind the deposition or ramp, which can provide a separation cavity, which leads to coolant flow residing in the cavity. Therefore, the 6 Copyright © 2016 by ASME deposition model D1.5 can improve film cooling effect.…”

Section: Effect Of Surface Deposition (Without Hole-blockage)mentioning

confidence: 99%

Combined Influence of Surface Deposition and Hole-Blockage on Film-Cooling Performances

Wang

Yuan

et al. 2016

Volume 5C: Heat Transfer

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Commercial aero-engines may operate in dust-laden environments, such as taking off and landing on desert ground or flying through volcano dust cloud, and foreign particles frequently deposit at hot surface and film hole-exits, which results in partial blockage of film holes, clog of cooling air, reduction in cooling effect, and could induce catastrophic damage. This problem has not been well solved up to now. This paper presents an experimental investigation on two surface deposition models (deposition limited to upstream of hole with a peak height of 1.5 diameter of hole called D1.5, and downstream forming a trench with a peak height of 1.0 diameter of hole, called D1) and two blockage models (leading edge of hole LB, and trailing edge TB), as well as two combined models D1.5-LB, and D1-TB. The experiments are conducted in a low speed water tunnel using Planar Laser Induced Fluorescence (PLIF) technique. Through this experiment, the following interesting phenomena, which were not reported in previous literatures, are reveled: 1) The effect of blockage ratio at leading edge on cooling performance of combined D1.5-LB is opposite to individual LB, i.e. in the case of combined D1.5-LB, a higher blockage ratio corresponds to a lower cooling effectiveness; whereas, for individual LB, the cooling effectiveness increases with the blockage ratios in the tested range. 2) At all blowing ratios, the cooling performances of combined D1.5-LB are better than that of perfect model D0-B0 (without deposition and blockage). At all blockage ratios tested in this experiment, in the case of combined D1.5-LB, a higher blowing ratio corresponds to a higher cooling effectiveness and a lager film coverage length. 3) At lower blockage ratios of 0.1 and 0.3, the overall-averaged cooling effectiveness of combined D1-TB is higher than that of perfect model D0-B0. At large blockage ratio 0.5, the blockage effect is dominant, and the averaged cooling effectiveness of combined model D1-TB is lower than that of D0-B0. In the case of individual deposition model D1-B0, although the lateral-averaged film cooling effectiveness is augmented, the area of film cooling is reduced.

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“…For the rod-based thermal element, we use the following interpolation functions of the temperature at the nodes as an approximate value: the temperature in the cross section is separated into average and perturbation temperature values [34]. Then, we can obtain the temperature at any point of the rod by using the following equation: …”

Section: Transient Temperature Field Of the Rod Elementmentioning

confidence: 99%

“…However, reports on the quantitative analysis of the thermodynamic behavior of SSRMs that consider the thermal environment in orbit are rare. Although a large number of works in the field of transient nonlinear thermal analysis of space vehicles have been conducted [32][33][34], not much attention has been focused on analyzing the thermodynamic behavior of SSRMs with an integrated TPS (ITPS).…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic analysis of a space station remote manipulator with a harmonic drive that considers an integrated thermal protection layer

Zhao

Yan

et al. 2015

Sci. China Technol. Sci.

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To eliminate anomalies and improve the performance of a space station remote manipulator (SSRM) used in a dynamically changeable thermal environment, we analyze the thermodynamic behavior of an SSRM that considers an integrated thermal protection system (ITPS). Solar radiative heat gain and loss become equally significant as conductive heat transfers through the interior of the SSRM on orbit. A thermodynamic model of the SSRM with a sandwich ITPS structure is established on the coupling between harmonic drive and changeable thermal environment. A motion precision is proposed to evaluate thermodynamic behavior under continuously changeable thermal circumstances. Simulation results indicate that the ITPS with a corrugated sandwich structure reduces the maximum amplitude of angular position errors to 41.6%, which helps improve the motion precision of the SSRM. The feasible regions for the SSRM in the Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) are analyzed, which shows that the proportion of feasible region in LEO is significantly larger than that in GEO. Space station remote manipulator, integrated thermal protection system, thermal analysis, harmonic drive, dynamic behavior Citation:Zhao J L, Yan S Z, Wu J N, et al. Thermodynamic analysis of a space station remote manipulator with a harmonic drive that considers an integrated thermal protection layer.

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Effects of upstream ramp on the performance of film cooling

Cited by 50 publications

References 14 publications

Validation of three dimensional film cooling modeling on convex surface for gas turbine blade

Validation of three dimensional film cooling modeling on convex surface for gas turbine blade

Combined Influence of Surface Deposition and Hole-Blockage on Film-Cooling Performances

Thermodynamic analysis of a space station remote manipulator with a harmonic drive that considers an integrated thermal protection layer

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