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2026 , Vol. 35 >Issue 1: 15 - 34

DOI: https://doi.org/10.1007/s11630-026-2215-9

Impact Mechanism of Blade Tip Clearance on Jet-Wake Characteristics in Supercritical CO2 Centrifugal Compressors

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  • 1. Department of Power Engineering, North China Electric Power University, Baoding 071003, China
    2. Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding 071003, China

网络出版日期: 2026-01-05

基金资助

The authors would like to acknowledge the support of the National Natural Science Foundation of China (No. 52076079), Natural Science Foundation of Hebei Province (E2022502052, E2022502048), and Fundamental Research Funds for the Central Universities (2023MS121).

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Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2026
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Impact Mechanism of Blade Tip Clearance on Jet-Wake Characteristics in Supercritical CO2 Centrifugal Compressors

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  • 1. Department of Power Engineering, North China Electric Power University, Baoding 071003, China
    2. Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding 071003, China

Online published: 2026-01-05

Supported by

The authors would like to acknowledge the support of the National Natural Science Foundation of China (No. 52076079), Natural Science Foundation of Hebei Province (E2022502052, E2022502048), and Fundamental Research Funds for the Central Universities (2023MS121).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2026
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摘要

超临界二氧化碳（S-CO2）的高密度特性使得离心压缩机的结构十分紧凑，较小的绝对叶顶间隙也会导致叶顶间隙相对值较大。与空气压缩机相比，这一结构特征征势必会带来叶轮出口紧凑空间中泄漏流动的显著增强，进而改变叶轮出口速度分布。本研究通过稳态模拟研究了不同相对叶顶间隙（CR = 0%、3.33%、6.66% 和 10%）对叶轮出口射流-尾迹的影响。结果表明：受尺寸效应影响，叶轮内部二次流与涡结构的类型及分布随叶顶间隙发生显著变化，进而影响叶轮出口的射流-尾迹和扩压器内失速区域的分布。当相对叶顶间隙超过一定界限时，部分二次流被限制在间隙内，沿叶顶间隙向叶轮出口流动，并在轮盖侧形成低流向速度区域。此外，在小相对间隙工况下，尾迹区主要受通道涡和分离涡影响。而随着间隙增大，通道二次流减弱而泄漏流增强，导致泄漏涡向高叶高区域扩展并占据主导，分离涡则在中高位置吸力侧形成。这最终导致叶轮出口尾迹核心区从轮毂侧转移至轮盖侧，同时扩压器内回流区域从低于20%叶高（近轮毂处）上移至超过80%叶高（近轮盖处）位置。

关键词： jet-wake; flow characteristics; supercritical CO2; centrifugal compressors

本文引用格式

ZHANG Lei, WANG Yongfu, WANG Yongsheng, YUAN Wei . Impact Mechanism of Blade Tip Clearance on Jet-Wake Characteristics in Supercritical CO2 Centrifugal Compressors[J]. 热科学学报, 2026 , 35(1) : 15 -34 . DOI: 10.1007/s11630-026-2215-9

Abstract

The high-density nature of supercritical carbon dioxide (S-CO2) allows for compact centrifugal compressor designs, where small absolute tip clearances result in relatively large normalized clearance ratios. This increases leakage flow at the impeller outlet, altering the velocity distribution, especially compared to air compressors. Steady-state simulations were conducted to investigate different relative tip clearances (CR=0%, 3.33%, 6.66%, and 10%). The results show that due to size effects, the types and distributions of secondary flows and vortices within the impeller vary significantly with tip clearance, affecting the jet-wake distribution at the impeller exit and the stall region in the diffuser. When the relative tip clearance exceeds a certain threshold, some secondary flow becomes trapped in the clearance, moving towards the impeller outlet and forming a low flow velocity region on the shroud side. Additionally, when the relative clearance is small, the wake region is primarily affected by channel and separation vortices. As the relative tip clearance increases, the secondary flow in the channel weakens, while the leakage flow intensifies, causing the leakage vortex to extend and dominate at higher blade heights, at the same time, the separation vortex to be formed near the suction side at mid to high positions. Consequently, the core region of the wake at the impeller outlet shifts from the hub side to the casing side, and the reverse flow region in the diffuser shifts from below 20% span (near the hub) to above 80% span (near the shroud).

Key words： jet-wake; flow characteristics; supercritical CO2; centrifugal compressors

参考文献

[1] Ameli A., Afzalifar A., Turunen-Saaresti T., et al., Centrifugal compressor design for near-critical point applications. Journal of Engineering for Gas Turbines and Power, 2019, 141(3): 031016.
[2] Cheng K., Qin J., Sun H., et al., Power optimization and comparison between simple recuperated and recompressing supercritical carbon dioxide Closed-Brayton-Cycle with finite cold source on hypersonic vehicles. Energy, 2019, 181: 1189–1201.
[3] Ming Y., Liu K., Zhao F., et al., Dynamic modeling and validation of the 5 MW small modular supercritical CO2 Brayton-Cycle reactor system. Energy Conversion and Management, 2022, 253: 115184.
[4] Son S., Heo J.Y., Kim N.I., et al., Reduction of CO2 emission for solar power backup by direct integration of oxy-combustion supercritical CO2 power cycle with concentrated solar power. Energy Conversion and Management, 2019, 201: 112161.
[5] Carraro G., Danieli P., Lazzaretto A., et al., A common thread in the evolution of the configurations of supercritical CO2 power systems for waste heat recovery. Energy Conversion and Management, 2021, 237: 114031.
[6] Zhang L., Zhou J., Zuo S., et al., Anti-freezing mechanism of the direct air-cooled system by splitting columns operation. International Communications in Heat and Mass Transfer, 2024, 158: 107883.
[7] Zhang L., Zhou J., Zuo S., et al., Effect mechanism of ambient air parameters on the thermal performance for cooling towers. Journal of Thermal Science and Engineering Applications, 2024, 16(1): 011011.
[8] Li Y., Ding J., Sun H., et al., Performance analysis of the inverted Brayton cycle in the atmospheric solid oxide fuel cell hybrid power system. Energy Conversion and Management, 2024, 316: 118828.
[9] Shaaban S., Design optimization of a centrifugal compressor vaneless diffuser. International Journal of Refrigeration, 2015, 60: 142–154.
[10] Wright S.A., Radel R.F., Vernon M.E., et al., Operation and analysis of a supercritical CO2 Brayton cycle. Sandia National Laboratories (SNL), Albuquerque, NM, USA, 2010, 87185-MS1136.
[11] Zhang L., Yang Z., Sun E., et al., Numerical simulation study on influence of equation of state on internal flow field and performance of s-CO2 compressor. Journal of Thermal Science, 2024, 33(3): 888–898.
[12] Zhang L., Yang F., An G., et al., Investigation of a rotating stall in a supercritical CO2 centrifugal compressor. Physics of Fluids, 2024, 36(5): 054102.
[13] Zhang L., An G., Lang J., et al., Investigation of the unsteady flow mechanism in a centrifugal compressor adopted in the compressed carbon dioxide energy storage system. Journal of Energy Storage, 2024, 104: 114488.
[14] Lopez A., Monje B., Sanchez D., et al., Effect of turbulence and flow distortion on the performance of conical diffusers operating on supercritical carbon dioxide. Turbo Expo: Power for Land, Sea, and Air, American Society of Mechanical Engineers, SAN Antonio, USA, 2013, 55294: V008T34A002. 
DOI: https://doi.org/10.1115/GT2013-94009.
[15] Liu Z., Wang P., Zhao B., Numerical investigation of the rotating instability uniqueness in a MW scale supercritical carbon dioxide centrifugal compressor. Korean Journal of Chemical Engineering, 2022, 39(11): 2935–2944.
[16] Cao R., Li Z., Deng Q., et al., Design and aerodynamic performance investigations of centrifugal compressor for 150 kW class supercritical carbon dioxide simple brayton cycle. Turbo Expo: Power for Land, Sea, and Air, American Society of Mechanical Engineers, London, UK, 2020, 84232: V011T031A019. 
DOI: https://doi.org/10.1115/GT2020-16156.
[17] Zhang H., Yang Y., Xu C., et al., Numerical study of the coherent characteristics of the blade tip of a micro centrifugal compressor and its application in a new unsteady casing-treatment experiment. Physics of Fluids, 2024, 36(1): 017139.
[18] Yang Z., Jiang H., Zhuge W., et al., Flow loss mechanism in a supercritical carbon dioxide centrifugal compressor at low flow rate conditions. Journal of Thermal Science, 2024, 33(1): 114–125.
[19] Cai R., Yang M., Yang B., et al., Study of unsteady shear flow near stall in a shrouded supercritical carbon dioxide centrifugal compressor. Physics of Fluids, 2024, 36(11): 114104.
[20] Gooding W.J., Fabian J.C., Key N.L., Laser doppler velocimetry characterization of unsteady vaned diffuser flow in a centrifugal compressor. Journal of Turbomachinery, 2020, 142(4): 041001.
[21] Stuart C., Spence S., Filsinger D., et al., A three-zone modeling approach for centrifugal compressor slip factor prediction. Journal of Turbomachinery, 2019, 141(3): 031008.
[22] Zheng Q., Liu S., Numerical investigation on the formation of jet-wake flow pattern in centrifugal compressor impeller. Turbo Expo: Power for Land, Sea, and Air, 2003, 36894: 755–764.
[23] Gooding W.J., Fabian J.C., Key N.L., LDV characterization of unsteady vaned diffuser flow in a centrifugal compressor. Journal of Turbomachinery, 2020, 142(4): 1–10.
[24] Hong S.S., Schleer M., Abhari R.S., Effect of tip clearance on the flow and performance of a centrifugal compressor. Fluids Engineering Division Summer Meeting, Hawaii, USA, 2003, 36975: 563–569.
[25] Chen Z., Yang S., Li X., et al., Investigation on leakage vortex cavitation and corresponding enstrophy characteristics in a liquid nitrogen inducer. Cryogenics, 2023, 129: 103606.
[26] Zeng L., Gao Z., Xu T., et al., Mechanism analysis of the vortex ring and its effects on an axial descending rotor. International Journal of Fluid Engineering, 2024, 1(2): 023101.
[27] Zhang L., He R., Wang X., et al., Study on static and dynamic characteristics of an axial fan with abnormal blade under rotating stall conditions. Energy, 2019, 170: 305–325.
[28] An G., Kang J., Zou Y., et al., Investigation of the unsteady flow in a transonic axial compressor adopted in the compressed air energy storage system. Journal of Energy Storage, 2023, 63: 106928.
[29] An G., Kang J., Wang L., et al., Decoupling and reconstruction analysis in a transonic axial compressor using the dynamic mode decomposition method. Physics of Fluids, 2023, 35(8): 084120.
[30] Schleer M., Song S.J., Abhari R.S., Clearance effects on the onset of instability in a centrifugal compressor. Journal of Turbomachinery, 2008, 130(3): 031002.
[31] Bulot N., Trébinjac I., Effect of the unsteadiness on the diffuser flow in a transonic centrifugal compressor stage. International Journal of Rotating Machinery, 2009, 2009(1): 932593.
[32] Zhang L., Zheng Z., Zhang Q., et al., Study of rotating stall in a centrifugal compressor with wide vaneless diffuser. Journal of Thermal Science, 2020, 29(3): 743–752.
[33] Zhang L., Kang J., Lang J., et al., Stall evolution mechanism of a centrifugal compressor with a wide-long vaneless diffuser. Journal of Thermal Science, 2024, 33(3): 899–913.
[34] Liu Z., Luo W., Zhao Q., et al., Preliminary design and model assessment of a supercritical CO2 compressor. Applied Sciences, 2018, 8(4): 595.
[35] Li X., Cao Z., Wei Z., et al., Theoretical model of energy conversion and loss prediction for multi-stage centrifugal pump as turbine. Energy Conversion and Management, 2025, 325: 119379.
[36] Schleer M., Abhari R.S., Clearance effects on the evolution of the flow in the vaneless diffuser of a centrifugal compressor at part load condition. Journal of Turbomachinery, 2008, 130(3): 031009.
[37] Hah C., Krain H., Secondary flows and vortex motion in a high-efficiency backswept impeller at design and off-design conditions. Journal of Turbomachinery, 1990, 112(1): 7–13.
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