A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect

Annular gas seals are critical components in turbomachines for restricting leakage and ensuring efficiency. Reducing seal clearance is the most direct method to minimize leakage. Flexible seals such as brush seals, leaf seals, and finger seals are typical solutions. These seals achieve minimal leaka...

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Main Authors: Weirong Wu, Qianlei Gu, Wanfu Zhang, Hongyu Gao, Yucong Zhang, Mingjie Zhang
Format: Article
Language:English
Published: Elsevier 2025-10-01
Series:Ain Shams Engineering Journal
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2090447925003600
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author Weirong Wu
Qianlei Gu
Wanfu Zhang
Hongyu Gao
Yucong Zhang
Mingjie Zhang
author_facet Weirong Wu
Qianlei Gu
Wanfu Zhang
Hongyu Gao
Yucong Zhang
Mingjie Zhang
author_sort Weirong Wu
collection DOAJ
description Annular gas seals are critical components in turbomachines for restricting leakage and ensuring efficiency. Reducing seal clearance is the most direct method to minimize leakage. Flexible seals such as brush seals, leaf seals, and finger seals are typical solutions. These seals achieve minimal leakage rates through extremely tight clearances, yet face inevitable rubbing risk during severe operational conditions. This paper proposes a novel flexible self-adaptive seal (FSS), featuring axial flexible teeth and radial rigid teeth. The radial deformation of flexible teeth, induced by the natural pressure differential between the outer and inner surface, enables adaptive clearance adjustment. With this effect, the inherent rub problem in traditional flexible seals is resolved. A two-way fluid–structure interaction (FSI) analysis was carried out, simulating the deformation characteristics and the flow field distribution for various operating conditions and flexible teeth geometric parameters. Results indicate that when leakage fluid passes through the seal clearance, a flow contraction effect occurs. This effect creates a low-pressure zone on the inner surface of the flexible teeth, while the outer surface exists higher cavity pressure. Under the pressure differential between the two surfaces, the flexible teeth deform toward the rotor center, enabling adaptive clearance adjustment. This effect contributes to the enhanced flow contraction, thus increasing the leakage resistance. The leakage reduction effect of FSS increases as the pressure ratios (PR) increase. For the case of PR = 9.9, the maximum leakage reduction ratio reaches 24 % compared to the traditional labyrinth seal. The proposed FSS offers critical advancements in sealing capability for high-parameter operational scenarios.
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publishDate 2025-10-01
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series Ain Shams Engineering Journal
spelling doaj-art-f2cbfab91cbc4f8f9ffc82a0af4b6b8f2025-07-19T04:38:14ZengElsevierAin Shams Engineering Journal2090-44792025-10-011610103619A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effectWeirong Wu0Qianlei Gu1Wanfu Zhang2Hongyu Gao3Yucong Zhang4Mingjie Zhang5School of Energy and Power Engineering, University of Shanghai for Science and Technology, 516, Jungong Road, Shanghai 200093, PR ChinaSchool of Energy and Power Engineering, University of Shanghai for Science and Technology, 516, Jungong Road, Shanghai 200093, PR ChinaSchool of Energy and Power Engineering, University of Shanghai for Science and Technology, 516, Jungong Road, Shanghai 200093, PR China; Corresponding author.School of Energy and Power Engineering, University of Shanghai for Science and Technology, 516, Jungong Road, Shanghai 200093, PR ChinaSchool of Energy and Power Engineering, University of Shanghai for Science and Technology, 516, Jungong Road, Shanghai 200093, PR ChinaSchool of Electrical and Power Engineering, Hohai University, Nanjing, Jiangsu Province 211100, PR ChinaAnnular gas seals are critical components in turbomachines for restricting leakage and ensuring efficiency. Reducing seal clearance is the most direct method to minimize leakage. Flexible seals such as brush seals, leaf seals, and finger seals are typical solutions. These seals achieve minimal leakage rates through extremely tight clearances, yet face inevitable rubbing risk during severe operational conditions. This paper proposes a novel flexible self-adaptive seal (FSS), featuring axial flexible teeth and radial rigid teeth. The radial deformation of flexible teeth, induced by the natural pressure differential between the outer and inner surface, enables adaptive clearance adjustment. With this effect, the inherent rub problem in traditional flexible seals is resolved. A two-way fluid–structure interaction (FSI) analysis was carried out, simulating the deformation characteristics and the flow field distribution for various operating conditions and flexible teeth geometric parameters. Results indicate that when leakage fluid passes through the seal clearance, a flow contraction effect occurs. This effect creates a low-pressure zone on the inner surface of the flexible teeth, while the outer surface exists higher cavity pressure. Under the pressure differential between the two surfaces, the flexible teeth deform toward the rotor center, enabling adaptive clearance adjustment. This effect contributes to the enhanced flow contraction, thus increasing the leakage resistance. The leakage reduction effect of FSS increases as the pressure ratios (PR) increase. For the case of PR = 9.9, the maximum leakage reduction ratio reaches 24 % compared to the traditional labyrinth seal. The proposed FSS offers critical advancements in sealing capability for high-parameter operational scenarios.http://www.sciencedirect.com/science/article/pii/S2090447925003600Annular gas sealLeakage performanceFlow contraction effectFluid-structure interactionComputational Fluid Dynamics (CFD)
spellingShingle Weirong Wu
Qianlei Gu
Wanfu Zhang
Hongyu Gao
Yucong Zhang
Mingjie Zhang
A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
Ain Shams Engineering Journal
Annular gas seal
Leakage performance
Flow contraction effect
Fluid-structure interaction
Computational Fluid Dynamics (CFD)
title A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
title_full A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
title_fullStr A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
title_full_unstemmed A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
title_short A flexible self-adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
title_sort flexible self adaptive seal concept for sealing performance enhancement by controlling the flow contraction effect
topic Annular gas seal
Leakage performance
Flow contraction effect
Fluid-structure interaction
Computational Fluid Dynamics (CFD)
url http://www.sciencedirect.com/science/article/pii/S2090447925003600
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