Effect of blade loading on fluid-induced exciting force and noise in centrifugal pumps
Yang Ailing1, Xu Yang1, Li Guoping2, Zhang Yi2
1.School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; 2.704th Research Institute, China Shipbuilding Industry Corporation, Shanghai 200031, China
Abstract：The unsteady three-dimensional turbulent flow fields in two centrifugal pumps are analyzed by using large eddy simulation method, then the structure vibration of the volute and the noise induced by the unsteady pressure are simulated with boundary element method. The pumps have an identical volute, impeller outlet diameter, blade outlet width, duty head and flow rate and rotational speed but different blade loadings. The hydraulic efficiency, flow field characteristics, pressure pulsation, volute vibration features and radiated noise from the pump are compared to investigate effects of the loading on hydraulic performance and fluid-induced exciting force. The results show that the hydraulic efficiency of the pump with the higher blade loading is not only 1.1%-2.9% better than that with the lower loading, but also has a more uniform flow field. The unsteady pressure on the wet surfaces of the volute and the exciting force applied on the impellers at blade passing frequency are dominated. The amplitude of pressure fluctuation in the pump with the higher blade loading is so remarkable that the maximum pressure fluctuation amplitude at the volute tongue is 42.6% higher compared with that in the pump with the lower loading. Likewise, the magnitude of unsteady radial thrust fluctuation on the pump with the higher blade loading is increased by 7.63% as well. The maximum vibration velocity and acceleration of the volute in the pump with the higher blade loading at the 2nd harmonic frequency is 5-6 times the frequency in the pump with the lower blade loading. Note that the directivity pattern of noise also shows an obvious difference in the two pumps, particularly, the sound pressure level from the pump with the higher blade loading is more violent than that with the lower loading in the range of 10°-310° polar angle. These results suggest that blade loading is an important factor that affects the exciting force and subsequently alters fluid-induced noise from a centrifugal pump. In addition, the hydraulic efficiency and exciting force should be taken into account together in design of low noise centri-fugal pumps.
杨爱玲, 徐洋, 李国平, 章艺. 叶片载荷对离心泵内流动激励力及噪声的影响[J]. 排灌机械工程学报, 2014, 32(1): 23-28.
Yang Ailing, Xu Yang, Li Guoping, Zhang Yi. Effect of blade loading on fluid-induced exciting force and noise in centrifugal pumps. Journal of Drainage and Irrigation Machinery Engin, 2014, 32(1): 23-28.
[1]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 & Fluids, 2009,38(6): 1243-1257.[2]Berten S, Dupont P, Farhat M, et al. Rotor-stator inte-raction induced pressure fluctuations: CFD and hydroacoustic simulaton in the stationary components of a multistage centrifugal pump[C]//Proceedings of the 5th Joint ASME/JSME Fluids Engineering Conference. San Diego, California,USA:ASME,2007: 1-8.[3]丛国辉,王福军.双吸离心泵隔舌区压力脉动特性分析[J].农业机械学报,2008,39(6): 60-67. Cong Guohui, Wang Fujun. Numerical investigation of unsteady pressure fluctuations near volute tongue in a double-suction centrifugal pump[J]. Transactions of the Chinese Society for Agricultural Machinery, 2008, 39(6): 60-67.(in Chinese)[4]Barrio R, Blanco E, Parrondo J, et al. The effect of impeller cutback on the fluid-dynamic pulsations and load at the blade-passing frequency in a centrifugal pump[J]. Journal of Fluids Engineering, 2008,130(11):111102.[5]王洋,张翔,黎义斌.离心泵变工况流场分析及径向力数值预测[J].排灌机械,2008, 26(5): 18-22. Wang Yang, Zhang Xiang, Li Yibin. Off-design flow field analysis and radial force prediction of centrifugal pump[J]. Drainage and Irrigation Machinery, 2008, 26(5):18-22.(in Chinese)[6]Barrio R, Parrondo J, Blanco E. Numerical analysis of the unsteady flow in the near-tongue region in a volute-type centrifugal pump for different operating points[J]. Computers & Fluids, 2010,39(5):859-870.[7]González J, Parrondo J, Santolaria C, et al. Steady and unsteady radial forces for a centrifugal pump with impe-ller to tongue gap variation[J]. Journal of Fluids Engineering, 2006,128(3):454-462.[8]Yoshida Y, Tsujimoto Y, Kawakami T, et al. Unba-lanced hydraulic forces caused by geometrical manufacturing deviations of centrifugal impellers[J]. Journal of Fluids Engineering, 1998,120(3):531-537.[9]蒋爱华.流体激励诱发离心泵基座振动的研究[D].上海:上海交通大学机械系统振动国家重点实验室,2011.[10]Tan Y X, Wang H G, Yang A L, et al. Numerical prediction of hydrodynamic noise for a centrifugal pump[C]//Proceedings of the 2010 International Conference on Pumps and Fans, 2010:89-94.[11]王振宇,杨爱玲,戴韧. 离心泵流动诱导噪声的数值预测[J].机械工程学报,2012,48(1):162-167. Wang Zhenyu, Yang Ailing, Dai Ren. Numerical prediction of the flow-induced noise of centrifugal pump[J]. Journal of Mechanical Engineering, 2012,48(1):162-167.(in Chinese)
