Experimental study on the cavitation flow and the induced vibration characteristics of a mixed-flow water-jet pump
GONG Bo1，ZHANG Zhengchuan1，YIN Junlian1，XU Rui1，LI Ning2，WANG Dezhong1
1.School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2.Marine Design and Research Institute of China, Shanghai 200011, China
Abstract：In order to study the unsteady cavitation flow and its induced vibration characteristics in the water-jet pump, a high-speed camera and digital signal synchronization measurement platform was built. The cavitation flow, pressure pulsation, and vibration signals in the pump at different cavitation levels were acquired and analyzed. Empirical modal decomposition (EMD) and Hilbert-Huang Transform (HHT) were introduced to process and analyze the vibration signals. The results show that the cavitation of the top gap and the leaky cavitation of the top of the lobe appear in the water-jet pump. With the decreasing of inlet pressure of pump, the cavitation flow structure in the tip area of the blades develops from filamentary to sheet and then to cloudy. The rapidly rotating cavitation cloud will show an extremely unsteady characteristics, and the tailing of cavitation cloud will fall off to form perpendicular cavitation vortexes (PCVs); the small-scale PCVs dissipates in the middle of the flow channel, and with the further intensification of the cavitation, the scale of PCVs increases and moves to the pressure surface of the adjacent blade, resulting in the degradation of the water-jet pump performance. The change of flow structure characteristics with cavitation levels lead to a corresponding change in pressure fluctuation and induce an increase in vibration. The results of Hilbert-Huang transform show that the development of sheet cavitation and the collapse of large scale of cloudy cavitation vortex induce the increasing of broadband vibrations in the high frequency region; the PCVs induce rapid increasing of pressure fluctuations and vibrations at low frequencies. The trends of amplitude of high frequency, rotating frequency and shaft frequency at Hilbert marginal spectrum can be used to reflect the flow characteristics in the waterjet pump.
龚 波1,张正川1，尹俊连1, 许锐1，李宁2，王德忠1. 混流式喷水推进泵空化流动及其诱导振动特性的试验研究[J]. 振动与冲击, 2024, 43(2): 42-51.
GONG Bo1，ZHANG Zhengchuan1，YIN Junlian1，XU Rui1，LI Ning2，WANG Dezhong1. Experimental study on the cavitation flow and the induced vibration characteristics of a mixed-flow water-jet pump. JOURNAL OF VIBRATION AND SHOCK, 2024, 43(2): 42-51.
[1]. 黄彪，吴钦，王国玉. 非定常空化流动研究现状与进展[J]．排灌机械工程学报，2018，36(01):1-14.
HUANG Biao, WU Qin, WANG Guoyu. Progress and prospects of investigation into unsteady cavitating flows[J]. Journal of Drainage and Irrigation Machinery Engineering, 2018, 36(1): 1−14 (in Chinese).
[2]. Wang C C， Huang B， Wang G Y， et al. Unsteady pressure fluctuation characteristics in the process of breakup and shedding of sheet/cloud cavitation [J]. International Journal of Heat and Mass Transfer， 2017， 114: 769-785.
[3]. Wu H， Tan D， Miorini R L， et al. Three-dimensional flow structures and associated turbulence in the tip region of a waterjet pump rotor blade[J]. Experiments in Fluids， 2011， 51(6): 1721-1737.
[4]. 崔宗培．中国水利百科全书［Ｍ］．北京：中国水利水电出版社.
Cui Zongpei. Water Conservancy Encyclopedia China[M]. Beijing: China Water&Power Press
[5]. BRENNEN C E. Cavitation and bubble dynamics[M]. Oxford Engineering &. Sciences Series 44, Oxford University Press, 1995.
[6]. ZHANG M. CHEN H, WU Q, et al, Experimental and numerical investigation of cavitating vortical patterns around a Tulin hydrofoil [J]. Ocean Engineering, 2019, 173(1)-298- 307 .
[7]. GUENNOUN F, FARHAT M, BOUZIAD Y A, et al. Experimental investigation of a particular traveling bubble cavitation [C]// Fifth International Symposium on Cavitation,Osaka, Japan, 2003.
[8]. 刘韵晴,郭一梦,黄彪,等. 绕弹性水翼空化流激振动特性实验[J].空气动力学学报,2021,39(s):1−8.
Yunqing Liu, Biao Huang, Hanzhe Zhang, et al. Experimental investigation into fluid–structure interaction of cavitating flow [J]. Physics of Fluids, 2021,093307:1-14
[9]. Zobeiri A，Kueny J L，Farhat M，et al． Pump-turbine rotor-stator interactions ingenerating mode: pressure fluctuation in distributor channel[C]//Proceedings of the 23th IAHR Symposium on Hydraulic Machinery and Systems，2006．
[10]. Fisher R K，Seidel U，Grosse G，et al．A case study in resonant hydroelastic vibration: the causes of runner cracks and the solutions implemented for the Xiaolangdi hydroelectric project [C]//Proceedings of the 21th IAHＲ Symposium on Hydraulic Machinery and Systems，2002．
[11]. 王勇，刘厚林，袁寿其，等． 离心泵非设计工况空化振动噪声的试验测试［J］． 农业工程学报，2012，28( 2) : 35-38．
Wang Yong, Liu Houlin, Yuan Shouqi， et al. Experimental testing on cavitation vibration and noise of centrifugal pumps under off-design conditions[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2012，28( 2) : 35-38．
[12]. 潘中永，袁寿其． 泵空化基础［M］． 镇江: 江苏大学出版社，2013．
PAN Z Y，YUAN S Q． Fundamentals of cavitation in pumps[M]． Zhenjiang: Jiangsu University Press，2013( in Chinese) ．
[13]. Dreyer M， Decaix J， Munch-Alligne C， et al. Mind the gap: a new insight into the tip leakage vortex using stereo-PIV[J]. Experiments in Fluids， 2014， 55 (11): 1-13.
[14]. Wu H， Tan D， Miorini R L， et al. Three-dimensional flow structures and associated turbulence in the tip region of a waterjet pump rotor blade[J]. Experiments in Fluids， 2011， 51 (6): 1721-1737.
[15]. Miorini R L， Wu H， Tan D， et al. Three-Dimensional Structure and Turbulence Within the Tip Leakage Vortex of an Axial Waterjet Pump[C]. // Asme-jsme-ksme Joint Fluids Engineering Conference. 2011.
[16]. TAN D， LI Y， WILKES I， et al． Experimental investigation of the role of large scale cavitating vortical structures in performance breakdown of an axial waterjet pump［J］． Journal of Fluids Engineering，2015，137( 11): 317-320．
[17]. 张德胜,王海宇,施卫东等.不同空化数下轴流泵叶顶间隙区空化特性[J].农业机械学报,2014,45(02):115-121.
Zhang Desheng, Wang Haiyu, Shi Weidong, et al. Tip Clearance Cavitation Characteristics in Axial Flow Pump under Different Cavitation Numbers[J]. Transactions of the Chinese Society for Agricultural Machinery. 2014,45(02):115-121.
[18]. 沈熙,张德胜,刘安等.轴流泵叶顶泄漏涡与垂直涡空化特性[J].农业工程学报,2018,34(12):87-94.
Shen Xi, Zhang Desheng, Liu An, et al. Cavitation characteristics of tip leakage vortex and suction-side-perpendicular vortices in axial flow pump [J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2018, 34(12): 87 － 94. (in Chinese with English abstract)
[19]. 吴钦，郭一梦，刘韵晴等. 非定常空化流动及其诱导振动特性研究综述[J]. 空气动力学学报
WU Qin, GUO Yimeng, LIU Yunqing, et al. Review on the cavitating flow-induced vibrations[J]. Acta Aerodynamica Sinica, 2020, 38(4):746−760 (in Chinese).
[20]. 李伟,季磊磊,施卫东,杨勇飞,平元峰,张文全.基于Hilbert-Huang变换的混流泵流动诱导振动试验[J].农业工程学报,2018,34(02):47-54.
Li Wei, Ji Leilei, Shi Weidong, Yang Yongfei, Ping Yuanfeng, Zhang Wenquan. Experiment of flow induced vibration of mixed-flow pump based on Hilbert-Huang transform[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2018, 34(2): 47－54. (in Chinese with English abstract)
[21]. Mandic D P, Rehman N U, Wu Z, et al. Empirical mode decomposition-based time-frequency analysis of multivariate signals: The power of adaptive data analysis [J]. Signal Processing Magazine IEEE, 2013. 30(6): 74-86.
[22]. Yin Y, Xiong H U. HHT time-frequency energy spectrum technique used in main joints condition monitoring of QCC track [J]. Procedia Engineering, 2012. 37: 197-201.
[23]. Huang N, Shen S. Hilbert-Huang Transform and Its Applications. World Scientific Publishing; 2005.
[24]. Hui Sun， Yin Luo，et al. Hilbert spectrum analysis of unsteady characteristics in centrifugal pump operation under cavitation status[J].Annals of Nuclear Energy,2018,114:607-615.
[25]. 魏小玲,冯永保,刘珂等.基于EEMD的圆弧齿轮泵空化流动及振动特性试验研究[J].振动与冲击,2022,41(10):90-98.
WEI Xiaoling，FENG Yongbao，LIU Ke, et al. Experimental study on the cavitation flow and vibration characteristics of circular arc gear pumps based on EEMD[J]. JOURNAL OF VIBRATION AND SHOCK. 2022,41(10):90-98.
[26]. 李胜才. 动力空化流压力脉动特性研究[J]. 华北水利水电学院学报, 1986, 7(1): 1−17.
LI S C. Investigations on the characteristics of pressure pulsations for dynamic cavitating flows[J]. Journal of North China Institute of Water Conservancy and Hydroelectric Power, 1986, 7(1): 1−17 (in Chinese).
[27]. 龙云,冯超,王路逸,等.喷水推进泵临界空化工况空化流态试验[J].北京航空航天大学学报,2019,45(08):1512-1518.
LONG Y ，FENG C ，WANG L Y ，et al． Experiment on cavitation flow in critical cavitation condition of water-jet propulsion pump[J]．Journal of Beijing University of Aeronautics and Astronautics ，2019 ，45 ( 8 ) : 1512-1518 ( in Chinese ) ．
