Abstract:This paper aims to investigate the unsteady cavitation behaviour and the corresponding cavity induced vibrations. The high-speed camera and a single point laser Doppler vibrometer(LDV)are used to analyze the transient cavitating flow structures and the corresponding structural vibration characteristics. The k-ω SST turbulence model with the turbulence viscosity correction and the Zwart cavitation model are introduced to the present simulations. The fluid model is coupled with a chordwise rigid, two degrees-of-freedom system with the hybrid coupled fluid structure interaction model. The results showed that the maximum vibration amplitude keeps relatively small for the inception cavitation and sheet cavitation, increases dramatically for the cloud cavitation and declines for the supercavitation. The main flow-induced frequency, which is in accord with the cavity shedding frequency, reduces with the decrease of the cavitation number. Owing to the disturbance caused by the flow-induced flutter and deformation of the foil, it presented more complex cavitation patterns for the flexible hydrofoil, as well as more components in the vibration spectra.
王宁, 黄彪, 吴钦, 王国玉. 绕水翼空化流动及振动特性的试验与数值模拟[J]. 排灌机械工程学报, 2016, 34(4): 321-327.
WANG Ning, HUANG Biao, WU Qin, WANG Guoyu. Experiment and numerical simulation of vibration characteristics of hydrofoil in cavitating flow. Journal of Drainage and Irrigation Machinery Engin, 2016, 34(4): 321-327.
[1]韩国明, 张信志, 刘保国. 大型水轮发电机组振动稳定性分析与设计准则[J]. 中国机械工程, 2002,13(8):634-636. HAN Guoming, ZHANG Xinzhi, LIU Baoguo. Dynamic analysis and design criteria of vibration stability for large hydro-generator units[J]. China mechanical engineering, 2002,13(8):634-636.(in Chinese)[2]陆燕荪. 中国水电设备制造业的现状与展望[J]. 铸造纵横, 2007(4):8-10. LU Yansun. Status and developing perspective of China′s hydro equipment industry[J]. Foundry panorama, 2007(4):8-10.(in Chinese)[3]陈喜阳, 郭庆, 孙建平,等. 空化对离心泵低频水力振动影响的数值研究[J]. 华中科技大学学报(自然科学版), 2014,42(6): 6-11. CHEN Xiyang, GUO Qing, SUN Jianping, et al. Numerical study on effects of cavitations for centrifugal pump low frequency hydraulic vibration[J]. Journal of Huazhong University of Science and Technology(natural science edition), 2014,42(6):6-11.(in Chinese)[4]顾巍, 何友声, 胡天群. 轴对称体空泡流的噪声特性与空泡界面瞬态特征[J]. 上海交通大学学报, 2000,34(8):1026-1030. GU Wei, HE Yousheng, HU Tianqun. Noise feature of cavitation flows on axisymmetric bodies and transient characteristics of cavity interface[J]. Journal of Shanghai Jiaotong University, 2000,34(8): 1026-1030.(in Chinese)[5]李忠, 杨敏官, 高波,等. 空化诱发的轴流泵振动特性实验研究[J]. 工程热物理学报, 2012, 33(11):1888-1891. LI Zhong, YANG Minguan, GAO Bo, et al. Experimental study on vibration characteristics induced by cavitation of axial-flow pump[J]. Journal of engineering thermophysics, 2012,33(11):1888-1891.(in Chinese)[6]KAWANAMI Y, KATO H, YAMAGUCHI H, et al. Mechanism and control of cloud cavitation[J]. Journal of fluids engineering, 1997,119(4):788-794.[7]CHEN Guanghao, WANG Guoyu, HU Changli, et al. Combined experimental and computational investigation of cavitation evolution and excited pressure fluctuation in a convergent-divergent channel[J]. International journal of multiphase flow, 2015,72:133-140.[8]HUANG Biao, WANG Guoyu, ZHAO Yu, et al. Physical and numerical investigation on transient cavitating flows[J]. Science China(technological sciences), 2013,56(9):2207-2218.[9]WILLIAMSON C H K, GOVARDHAN R. Vortex-induced vibrations[J]. Annual review of fluid mechanics, 2004,36:413-455.[10]王文全,张立翔,闫妍,等. 不同雷诺数下弹性薄板流激振动实验[J]. 北京工业大学学报, 2012,38(1):55-59. WANG Wenquan, ZHANG Lixiang, YAN Yan, et al. Fluid-jinduced vibrations of thin elastic plate for different inflow Reynolds numbers[J]. Journal of Beijing University of Technology, 2012,38(1):55-59.(in Chinese)[11]AUSONI P, FARHAT M, ESCALER X. Cavitation influence on Kármán vortex shedding and induced hydrofoil vibrations[J]. Journal of fluids engineering, 2007,129(8):966-973.[12]WU Qin, HUANG Biao, WANG Guoyu, et al. Experimental and numerical investigation of hydroelastic response of a flexible hydrofoil in cavitating flow[J]. International journal of multiphase flow, 2015,74:19-33.[13]MENTER F R. Improved two-equation k-ω turbulence models for aerodynamic flows[R]. Washington, US: NASA Technical Memorandum, 1992.[14]COUTIER-DELGOSHA O, FORTES-PATELLA R, REBOUD J L. Evaluation of the turbulence model influence on the numerical simulations of unsteady cavitations[J]. Journal of fluids engineering, 2003,125(1):38-45.[15]HUANG Biao, DUCOIN A, YOUNG Yinlu. Evaluation of cavitation models for prediction of transient cavitating flows around a stationary and a pitching hydrofoil[C]//Proceedings of the 8th International Symposium on Cavitations. Singapore: Research Publishing Services, 2012:601-608.[16]THEODORSER T. General theory of aerodynamic instability and the mechanism of flutter[R]. Washington, US: National Advisory Committee for Aeronautics, 1935,496:291-311.