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Tip clearance

About: Tip clearance is a research topic. Over the lifetime, 2637 publications have been published within this topic receiving 32671 citations.


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Proceedings ArticleDOI
01 Jan 2004
TL;DR: In this paper, a numerical study has been performed to simulate the tip leakage flow and heat transfer on the first stage of a high-pressure turbine, which represents a modern gas turbine blade geometry.
Abstract: in Undetermined A numerical study has been performed to simulate the tip leakage flow and heat transfer on the first stage of a high-pressure turbine, which represents a modern gas turbine blade geometry. The low Re k-ω (SST) model is used to model the turbulence. Calculations are performed for both a flat and a squealer blade tip for three different tip gap clearances. The computations were carried out using a single blade with periodic conditions imposed along the boundaries in the circumferential (pitch) direction. The predicted tip heat transfer and static pressure distributions show reasonable agreement with experimental data. It was also observed that the tip clearance has a significant influence on local tip heat transfer coefficient distribution. The flat tip blade provides a higher overall heat transfer coefficient than the squealer tip blade. (Less)

21 citations

Journal ArticleDOI
TL;DR: In this article, the flow induced by the clearance between the tip of an isolated airfoil and an end-plate is investigated numerically, using a zonal approach with large-eddy simulation in the region of interest.
Abstract: The flow induced by the clearance between the tip of an isolated airfoil and an end-plate is investigated numerically, using a zonal approach with large-eddy simulation in the region of interest. The results are analyzed in comparison with available experimental data, presented in a companion paper. The incoming boundary layer and the pressure distribution around the blade are evaluated. The description of the inflow-jet deviation, with an averaged approach, enables to represent the proper loading on the airfoil. Also, particular attention is paid to the powerful tipleakage vortex. The vortex characteristics are investigated using specific functions to locate its center and quantify its width. Overall, good results are obtained for the flow statistics and spectra. Furthermore, a very good description of the far-field pressure is achieved using the acoustic analogy, and the results confirm that the tip-flow essentially radiates in the central frequency range (0.7 kHz, 7 kHz).

20 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the leakage loss caused by leaks through the impeller tip clearance for a centrifugal compressor and found that the average compressor performance would be reduced by about 4 percent when the relative clearance was increased from 0.0125 to 0.125 and the resulting leakage loss was dependent on the Reynolds number.
Abstract: Fluid loss caused by leaks through the impeller tip clearance was investigated for a centrifugal compressor. Operating conditions, Reynolds number, and clearance were varied independently during the experiment. It was found that the average compressor performance would be reduced by about 4 percent when the relative clearance was increased from 0.0125 to 0.125 and the resulting leakage loss was dependent on the Reynolds number, the tendency of which was just opposite in case of wall friction loss, as was well-known. Moreover, a determination of the leakage loss coefficient was made as a function of the relative clearance, relative leak level and the Reynolds number as the result of this experiment.

20 citations

Journal ArticleDOI
Kehan Zhou1, Jiangfeng Wang1, Jiaxi Xia1, Yumin Guo1, Pan Zhao1, Yiping Dai1 
TL;DR: In this article, the design study of an S-CO2 radial inflow turbine based on system optimization is conducted, and the CFD simulation of the turbine under design and offdesign conditions is performed, and tip clearance analysis is conducted to evaluate the turbine performance.

20 citations

Proceedings ArticleDOI
13 Jun 1994
TL;DR: In this paper, the performance of a low speed axial turbine followed by a second stage nozzle is measured with particular reference to the understanding of tip clearance effects in a real machine and to possible benefits of streamlined low loss rotor tips.
Abstract: The performance of a low speed axial turbine followed by a second stage nozzle is measured with particular reference to the understanding of tip clearance effects in a real machine and to possible benefits of streamlined low loss rotor tips.A radiused pressure edge was found to improve the performance of b single stage and of a one and a half stage turbine at the small tip clearance levels for which the radius was selected. This is in contrast to cascade results where mixing loss reduced the benefits of such tips. Clearance gap flow appears therefore to be just like other turbine flow where the loss mechanism of separation must be avoided. Loss formation within and downstream of a rotor are more complex than previously realized and do not obey the simple rules that have been used to design for minimum tip clearance loss. For example, approximately 48% of the tip leakage mass flow within a rotor appears to be a flat wall jet rather than a wrapped up vortex.The second stage nozzle efficiency was found to be significantly higher than for the first stage and to even increase with tip clearance. This is a surprising result since it means that not only is there a reduction in secondary flow loss but also that rotor leakage and rotor secondary flows do not generate downstream mixing loss.Copyright © 1994 by ASME

20 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202354
2022149
202189
2020111
2019116
201897