Abstract:In order to study steady and transient characteristics of fluid flow in centrifugal multistage pumps, the unsteady flow field in two stages of a multistage centrifugal pump made of stainless steel was simulated under design flow condition by making use of ANSYS CFX and the standard k-ε turbulence model. The performance curves predicted are in good agreement with the experimental data, validating the accuracy of the flow models and numerical methods. Additionally, four monitoring points are specified on the pressure and suction sides in a flow passage of the impeller, respectively; meanwhile other six monitoring points are positioned in various locations in a flow passage of the diffuser and guide vane. The pressure pulsation characteristics are analysed in time and frequency domains at these points. The results show that the rotor-stator interaction between impeller and guide vane is the cause for the static pressure fluctuation, and the average fluctuation of static pressure increases gradually from the inlet to the outlet of impeller. The shape of integrally formed stamping impeller can affect the pressure pulsation in the diffuser, and the pressure pulsation in one period is similar in another. The influence of rotor-stator interaction is dominated in the first guide vane; as a result, the pressure fluctuation is in 3 times blade passing frequency in the middle and at the outlet of guide vane, but is in 1 time blade passing frequency only at the other locations. The pressure pulsation in the diffuser is in a frequency as low as blade passing frequency.
[1]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)[2]ZOBEIRIi A, KUENY J L, FARHAT M, et al. Pump-turbine rotor-stator interactions in generating model: Pressure fluctuation in distributor channel[C]//Proceedings of the 23rd IAHR Symposium on Hydraulic Machinery and Systems, 2006: 17-31.[3]袁寿其,何有世,袁建平,等. 带分流叶片的离心泵叶轮内部流场的PIV测量与数值模拟[J]. 机械工程学报,2006,42(5):60-63. YUAN Shouqi, HE Youshi, YUAN Jianping, et al. PIV measurements and numerical simulations of flow in centrifugal pump impellers with splitting vanes[J]. Chinese journal of mechanical engineering, 2006, 42(5): 60-63.(in Chinese)[4]耿少娟,聂超群,黄伟光,等. 不同叶轮形式下离心泵整机非定常流场的数值研究[J]. 机械工程学报,2006,42(5):27-31. GENG Shaojuan, NIE Chaoqun, HUANG Weiguang, et al. Numerical study of unsteady flow in centrifugal pump with different type of impellers[J]. Chinese journal of mechanical engineering, 2006, 42(5): 27-31.(in Chinese)[5]GONZÁLEZ J, SANTOLARIA C. Unsteady flow structure and global variables in a centrifugal pump[J]. Journal of fluids engineering, 2006, 128(9):937-946.[6]王川,陆伟刚,施卫东,等. 不锈钢冲压潜水井泵的数值计算与试验验证[J]. 江苏大学学报(自然科学版),2012,33(2):176-180. WANG Chuan, LU Weiguang, SHI Weidong, et al. Numerical calculation and experimental verification of stainless steel stamping submersible well pump[J]. Journal of Jiangsu University(natural science edition), 2012, 33(2): 176-180.(in Chinese)[7]刘阳,袁寿其,袁建平,等. 离心泵的压力脉动研究进展[J]. 流体机械,2008,36(9):33-37. LIU Yang, YUAN Shouqi, YUAN Jianping, et al. Overview of pressure fluctuation in centrifugal pump[J]. Fluid machinery, 2008, 36(9): 33-37.(in Chinese)[8]周岭,施卫东,陆伟刚,等. 深井离心泵内部非定常流动的压力脉动特性分析[J]. 农业工程学报,2011,27(10):44-49. ZHOU Ling, SHI Weidong, LU Weigang, et al. Analysis on pressure fluctuation of unsteady flow in deep-well centrifugal pump[J]. Transactions of the CSAE, 2011, 27(10): 44-49.(in Chinese)[9]靳栓宝,王永生,常书平,等. 混流泵内流场压力脉动特性研究[J]. 农业机械学报,2013,44(3): 64-68. JIN Shuanbao, WANG Yongsheng, CHANG Shuping, et al. Pressure fluctuation of interior flow in mixed-flow pump[J]. Transactions of the Chinese society for agricultural machinery, 2013, 44(3): 64-68.(in Chinese)[10]HAYASHI I, KANEKO S. Pressure pulsations in piping system excited by a centrifugal turbomachinery taking the damping characteristics into consideration[J]. Journal of fluids and structures, 2014, 45: 216-234.[11]ZHANG Desheng, SHI Weidong, CHEN Bin, et al. Unsteady flow analysis and experimental investigation of axial-flow pump[J]. Journal of hydrodynamics, Ser.B, 2010, 22(1): 35-44.[12]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: 1243-1257.[13]率志君,张权,陈春来,等. 多级离心泵整机流场三维非稳态湍流压力脉动特性分析[J]. 哈尔滨工程大学学报,2013,34(3):306-311. SHUAI Zhijun, ZHANG Quan, CHEN Chunlai, et al. Characteristic analysis of three-dimensional unsteady turbulent pressure fluctuation in whole flow field of multi-stage centrifugal pump[J]. Journal of Harbin Engineeri-ng University, 2013, 34(3): 306-311.(in Chinese)[14]蒋庆磊,翟璐璐,吴大转,等. 多级离心泵内叶轮出口压力脉动研究[J]. 工程热物理学报,2012,33(4):599-602. JIANG Qinglei, ZHAI Lulu, WU Dazhuan, et al. Pressure fluctuation at impeller outlet in multistage pump[J]. Journal of engineering thermophysics, 2012, 33(4):599-602.(in Chinese)[15]司乔瑞,袁寿其,袁建平,等. 叶片与隔舌干涉对离心泵性能和压力脉动影响的数值研究[J]. 流体机械,2012,40(8):22-26. SI Qiaorui, YUAN Shouqi, YUAN Jianping, et al. Effect of interaction between blade and volute tongue of centrifugal pumps on the performance and pressure pulsation[J]. Fluid machinery, 2012, 40(8): 22-26.(in Chinese)[16]PAVESI G, CAVAZZINI G, ARDIZZON G. Time-frequency characterization of the unsteady phenomena in a centrifugal pump[J]. International journal of heat and fluid Flow, 2008,29(5):1527-1540.[17]ZHANG M, TSUKAMOTO H. Unsteady hydrodynamic forces due to rotor-stator interaction on a diffuser pump with identical number of vanes on the impeller and diffuser[J]. Journal of fluids engineering, 2005, 127(4): 743-751.