Instability analysis under part-load conditions in centrifugal pump
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In this study, a centrifugal pump with a specific speed of 39.12 m×min-1×m3s-1 is treated to analyze the flow instability under part-load conditions by numerical simulation and experimental test. For calculations, the RANS method, coupled with the k-ω SST turbulence model, is adopted. Numerical results at different operation points are compared with available experimental data, such as hydraulic performance and flow field information by particle image velocimetry. The numerical and experiment results agree well. The flow simulation indicates a strong reverse flow at the passage upstream impeller inlet, and the energy loss in the impeller is the largest under part-load conditions among all flow components in the pump. In one impeller revolution, one blade-to-blade flow passage is always nearly blocked off by the rotating stall occurring at the impeller inlet for each instant, and the blockage induces a jet flow with large velocity at the next blade-to-blade flow passage along the rotational direction of the impeller. The blockage and the jet flow in the blade-to-blade flow passages will make the flow unstable inside the impeller and cause performance breakdown and pressure vibration under part-load conditions for the pump.
KeywordsCentrifugal pump Flow instability Part-load conditions Rotating stall
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- J. Y. Mao, S. Q. Yuan, J. F. Zhang, Y. L. Li and Y. F. Wang, Analysis of inner flow characteristics in low specific speed centrifugal pump around hump conditions, Journal of Drainage and Irrigation Machinery Engineering (JDIME), 33 (4) (2015) 283–289.Google Scholar
- J. G. Mou, S. C. Zhang, S. H. Zheng and H. Y. Deng, Reason for centrifugal pump performance curve hump and the elimination method, Transactions of the Chinese Society of Agricultural Machinery, 37 (4) (2006) 56–59.Google Scholar
- O. Braun, Part-load flow in radial centrifugal pumps, Lausanne: Ecole polytechnique fédérale de Lausanne (Epfl) (2009).Google Scholar
- A. Guedes, J. L. Kueny, G. D. Ciocan and F. Avellan, Unsteady rotor-stator analysis of hydraulic pump-turbine: CFD and experimental approach, Proceedings of 21st IAHR Symposium on Hydraulic Machinery and Systems, Lausanne, Sweden (2002).Google Scholar
- Y. Li, X. J. Li, Z. C. Zhu and F. Q. Li, Investigation of unsteady flow in a centrifugal pump at low flow rate, Advances in Mechanical Engineering, 8 (12) (2016) 1–8.Google Scholar
- S. Berten, P. Dupont, L. Fabre, M. Kayal, F. Avellan and M. Farhat, Experimental investigation of flow instabilities and rotating stall in a high energy centrifugal pump stage, Proceedings of ASME 2009 Fluids Engineering Division Summer Meetings, Vail, Colorado, USA (2009) 78562.Google Scholar
- G. D. Ciocan and J. L. Kueny, Experimental analysis of rotor-stator interaction in a pump-turbine, Proceedings of 23th IAHR Symposium on Hydraulic Machinery and Systems, Yokohama, Japan (2006) 216–226.Google Scholar
- D. K. Walters and D. Cokljat, A three-equation eddyviscosity model for Reynolds-averaged Navier-Stokes simulations of transitional flow, Journal of Fluids Engineering, 130 (12) (2008) 121401.Google Scholar