Abstract
The stall is an unsteady flow phenomenon that always causes instabilities and low efficiency for pumps. This paper focuses on the unsteady flow structures and evolutions under two types of stall conditions in centrifugal pump impellers. Two centrifugal pump impellers, one with 6 and another with 5 blades, are considered and a developed large-eddy simulation method is adopted. The results show that the alternative stall occurs in the impeller with 6 blades, while, the rotating stall is observed in that with 5 blades. The flow structure and the pressure fluctuation characteristics are further analyzed. For the alternative stall, the stall cells are fixed relative to the impeller, but a large vortex in the stalled passage is always swaying. The outlet vortex is generated from it, and then develops and sheds periodically. For the rotating stall, the stall cells first occur in the suction side of the blade. With the growth of the stall cells, the block area gradually increases until the inlet region is almost blocked, then moves to the pressure side with a continuous decay. When the rotating stall occurs, the amplitude of the pressure fluctuation is much larger than that under the alternative stall condition. The propagation of the stall cells has a significant effect on the pressure fluctuations in the impeller.
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References
Brennen C. E. Hydrodynamics of pumps [M]. New York, USA: Cambridge University Press, 2011, 146–148.
Masahiro M., Maeda H., Umeki I. et al. Unstable headflow characteristic generation mechanism of a low specific speed mixed flow pump [J]. Journal of Thermal Science, 2006, 15(2): 115–120.
Zhou P. J., Wang F. J., Yang Z. J. Impeller-volute interaction around tongue region in centrifugal pump under rotating stall condition [J]. Transactions of the Chinese Society of Agricultural Engineering, 2015, 31(7): 85–90(in Chinese).
Pei J., Yuan S. Q., Li X. J. et al. Numerical prediction of 3-D periodic flow unsteadiness in a centrifugal pump under part-load condition [J]. Journal of Hydrodynamics, 2014, 26(2): 257–263.
Pacot O., Kato C., Guo Y. et al. Large eddy simulation of the rotating stall in a pump-turbine operated in pumping mode at a part-load condition [J]. Journal of Fluids Engineering, 2016, 138(11): 111102.
Zhou P., Wang F., Mou J. Investigation of rotating stall characteristics in a centrifugal pump impeller at low flow rates [J]. Engineering Computations, 2017, 34(6): 1989–2000.
Shibata A., Hiramatsu H., Komaki S. et al. Study of flow instability in off design operation of a multistage centrifugal pump [J]. Journal of Mechanical Science and Technology, 2016, 30(2): 493–498.
Pedersen N., Larsen P. S., Jacobsen C. B. Flow in a centrifugal pump impeller at design and off-design conditions: Part I: Particle image velocimetry (PIV) and laser Doppler velocimetry (LDV) measurements [J]. Journal of Fluids Engineering, 2003, 125(1): 61–72.
Johnson D. A., Pedersen N., Jacobsen C. B. Measurements of rotating stall inside a centrifugal pump impeller [C]. ASME 2005 Fluids Engineering Division Summer Meeting, Houston, USA, 2005, 1281–1288.
Feng J., Benra F., Dohmen H. J. Time-resolved particle image velocimetry (PIV) measurements in a radial diffuser pump [C]. ASME 2009 Fluids Engineering Division Summer Meeting, Colorado, USA, 2009, 323–329.
Ullum U., Wright J., Dayi O. et al. Prediction of rotating stall within an impeller of a centrifugal pump based on spectral analysis of pressure and velocity data [J]. Journal of Physics: Conference Series, 2006, 52(1): 36–45.
Krause N., Zähringer K., Pap E. Time-resolved particle imaging velocimetry for the investigation of rotating stall in a radial pump [J]. Experiments in Fluids, 2005, 39(2): 192–201.
Feng J., Benra F., Dohmen H. J. Application of different turbulence models in unsteady flow simulations of a radial diffuser pump [J]. Forschung im Ingenieurwesen, 2010, 74(3): 123–133.
Braun O. Part load flow in radial centrifugal pumps [D]. Doctoral Thesis, Lausanne, Switzerland: École Polytechnique Fédérale de Lausanne, 2009.
Byskov R. K., Jacobsen C. B., Pedersen N. Flow in a centrifugal pump impeller at design and off-design conditions: Part II: Large eddy simulations [J]. Journal of Fluids Engineering, 2003, 125(1): 73–83.
Lucius A., Brenner G. Numerical simulation and evaluation of velocity fluctuations during rotating stall of a centrifugal pump [J]. Journal of Fluids Engineering, 2011, 133(8): 081102.
Lu H., Christopher C. J. Structural subgrid-scale modeling for large-eddy simulation: A review [J]. Acta Mechanica Sinica, 2016, 32(4): 567–578.
Zhou P. J., Wang F. J., Yang Z. F. et al. Investigation of rotating stall for a centrifugal pump impeller using various SGS models [J]. Journal of Hydrodynamics, 2017, 29(2): 235–242.
Yang Z. J., Wang F. J. A dynamic mixed nonlinear subgrid-scale model for large-eddy simulation [J]. Engineering Computations, 2012, 29(7): 778–791.
Emmons H. W., Pearson C. E., Grant H. P. Compressor surge and stall propagation [J]. Transactions of the ASME, 1955, 77(3): 455–469.
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Project supported by the National Nature Science Foundation of China (Grant No. 51709234, 51779226), the Natural Science Foundation of Zhejiang Provincial (Grant No. LQ17E090005).
Biography: Pei-jian Zhou (1986-), Male, Ph. D.
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Zhou, Pj., Dai, Jc., Li, Yf. et al. Unsteady flow structures in centrifugal pump under two types of stall conditions. J Hydrodyn 30, 1038–1044 (2018). https://doi.org/10.1007/s42241-018-0125-3
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DOI: https://doi.org/10.1007/s42241-018-0125-3