Computation of unsteady flow and performance prediction for centrifugal pump
Zhou Lingjiu1， Wang Zhanmin2， Jiang Dongzhi1
(1.College of Conservancy and Civil Engineering， China Agricultural University, Beijing 100083, China; 2.Tianjin Pumps and Machinery Group Company Ltd., Tianjin 300400, China)
Abstract：The unsteady flow in a centrifugal pump was computed by applying Reynoldsaveraged equations closed by SST k-ω model and slidemeshmethod. Taking leakage loss, disk friction loss and mechanical loss into account, the performance curves of pump were predicted based on the computation results of unsteady flow, and were compared with the experimental data. The results show that the head and shaft power fluctuate greatly with different relative position of impeller blade and diffuser volute for a given flow rate, and the fluctuation amplitudes increase with flow rate increasing. The performance curves predicted of the steady and unsteady flow computation have little difference at both large flow rate and design point, but have obvious difference at low flow rate. Compared with tested curves, the predicted head and shaft power curves are lower, and the predicted efficiency curve is similar. Because of little difference between steady and unsteady flow computation at design point, the results of steady flow computation is feasible for impeller design.
[1]Shahram D,Ahmad N.Theoretical,numerical and experimental investigation of centrifugal pumps in reverse operation[J].Experimental Thermal and Fluid Science,2008,32(8):1620-1627.[2]谈明高,刘厚林,吴贤芳.基于Fluent的离心泵水力性能预测技术[J].排灌机械,2008,26(3):22-25.Tan Minggao,Liu Houlin,Wu Xianfang.Hydraulic characteristic prediction technique of centrifugal pumps based on Fluent[J].Drainage and Irrigation Machinery,2008,26 (3):22-25.(in Chinese)[3]杨敏官,刘栋,贾卫东,等.离心泵叶轮内部三维湍流流动的分析[J].江苏大学学报:自然科学版,2006,27 (6):524-527.Yang Minguan,Liu Dong,Jia Weidong,et,al.Analysis on turbulent flow in impeller of centrifugal pump[J].Journal of Jiangsu University:Natural Science Edition,2006,27 (6):524-527.(in Chinese)[4]Jose G,Joaquin F,Eduardo B.Numerical simulation of the dynamic effects due to impeller-volute interaction in a centrifugal pump[J].Journal of Fluids Engineering,2002,124 (2):348-355.[5]Miguel A,Farid B,Smaine K.Numerical modelization of the flow in centrifugal pump:volute influence in velocity and pressure fields[J].International Journal of Rotating Machinery,2005 (3):244-255.[6]Spence R,Amaral-Teixeira J.A CFD parametric study of geometrical variations on the pressure pulsations and performance characteristics of a centrifugal pump[J].Computers and Fluids,2009,38(6):1243-1257.[7]Kitano M.Numerical study of unsteady flow in a centri-fugal pump[J].Journal of Turbomachinery,2005,127(2):363-371.[8]Yuan Shouqi,Ni Yongyan,Pan Zhongyong,et al.Unsteady turbulent simulation and pressure fluctuation analysis for centrifugal pumps[J].Chinese Journal of Mechanical Engineering,2009,22 (1):64-69.[9]关醒凡.现代泵技术手册[M].北京:宇航出版社,1998:532-542.[10]Gulich J F.Disk friction losses of closed turbomachine impellers[J].Forschung im Ingenieurwesen,2003,68(2):87-95.
