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| Head degradation mechanism research on mixed-flow pump under cavitation conditions |
| Shi Wei1,2, Zhang Daqing1, Pan Zhongyong1, Li Yanjun1, Yuan Shouqi1 |
| 1. Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.Jiangsu Water Supply Co.Ltd., for East Route of South-to-North Water Diversion, Nanjing, Jiangsu 210029, China |
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Abstract The cavitating flow in a mixed-flow pump with volute collector(the specific speed ns=449)under design condition was simulated numerically based on the cavitation model Rayleigh-Plesset equations and the SST turbulence model. The NPSHA-H curve was obtained accordingly.To investigate the inherence of mixed-flow pump cavitation breakdown condition and head degradation, the cavitation phenomenon in the impeller were comparatively analyzed under the inception,critical and severe cavitation conditions.The numerical simulation results and experimental ones were consistent with the error less than 5%. When the cavitation bubble in the flow passage adds up to a certain extent, it will make the liquid boundary layer separation and produce vortexes, which can be observed from the picture of vapor volume fraction distribution in impeller passage and streamline distribution on blade suction side. Vortex is the main cause of the mixed-flow pump cavitation breakdown and head degradation. The regularities of distribution of mixed-flow pump cavitating flow field were revealed.
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Received: 24 January 2013
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| [1]Brennen C E. Hydrodynamics of Pumps[M]. Oxford:Concepts ETI,Inc.& Oxford University Press,2011.[2]Pierrat D,Gros L,Pintrand G,et al.Experimental and numerical investigations of leading edge cavitation in a helico-centrifugal pump[C]//Proceedings of the 12th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery. Honolulu, Hawaii:[s.n.],2008.[3]Adrian S,Romeo S R,Liviu E A,et al.A new approach in numerical assessment of the cavitation behaviour of centrifugal pumps[J].International Journal of Fluid Machinery and Systems,2011,4(1):104-113.[4]Hironori Horiguchi, Shuhei Arai, Junichiro Fukutomi, et al. Quasi three-dimensional analysis of cavitation in an inducer[J]. Transactions of the Japan Society of Mechanical Engineers, 2004,126(5):709-715.[5]甘加业,薛永飞,吴克启.混流泵叶轮内空化流动的数值计算[J].工程热物理学报,2007,28(S1):165-168. Gan Jiaye,Xue Yongfei,Wu Keqi.Numerical prediction of cavitation in a mixed-flow pump[J].Journal of Engineering Thermophysics,2007,28(S1):165-168.(in Chinese)[6]王勇,刘厚林,袁寿其,等. 离心泵内部空化特性的CFD模拟[J].排灌机械工程学报,2011,29(2): 99-103. Wang Yong,Liu Houlin,Yuan Shouqi,et al.CFD simulation on cavitation characteristics in centrifugal pump[J].Journal of Drainage and Irrigation Machinery Engineering,2011,29(2): 99-103.(in Chinese)[7]Singhal Ashok K, Athavale Mahesh M, Li Huiying,et al.Mathematical basis and validation of the full cavitation model[J].Journal of Fluid Engineering,2002,124(3):617-624.[8]Schmidt Steffen J, Sezal Ismail H,Schnerr Günter H. Compressible simulation of high-speed hydrodynamics with phase change[C]// Proceedings of European Conference on Computational Fluid Dynamics.Netherlands:[s.n.], 2006.[9]李晓俊,袁寿其,潘中永,等.诱导轮离心泵空化条件下扬程下降分析[J].农业机械学报,2011,42(9):89-93. Li Xiaojun, Yuan Shouqi,Pan Zhongyong,et al.Analysis of cavitation head drop in centrifugal pump with inducer[J]. Transactions of the Chinese Society for Agricultural Machinery,2011,42(9):89-93.(in Chinese) |
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