Abstract:In order to investigate influences of re-entrant jet strength on periodical evolution of cavity attaching to the upper surface of a hydrofoil, several 2D meshes around a hydrofoil at different inflow angles are established. The distributions of pressure, velocity and phase features of cavitating flow field are analyzed by using CFD method. Unsteady cavitating flows over the 2D hydrofoil with different inflow angles are simulated with the RNG k-ε turbulence model and Schnerr-Sauer cavitation model. The re-entrant jet motion features and interaction with cavity are analyzed at 4°, 10° and 12° inflow angles and 0.91 cavitation number. Based on velocity, characteristic length and other parameters, a critical cavitation number is put forward to estimate the strength of re-entrant jet and serves a basis of judgment on change in cavity shape. The results show that the strength of re-entrant jet is an important factor influencing the structure of cavity. It is identified that the magnitude of criterial number can be correlated to different periodical stages and types of cavity.
王巍, 徐瑞铎, 羿琦, 王晓放. 回射流强度对水翼表面空化形态的影响[J]. 排灌机械工程学报, 2016, 34(11): 921-926.
WANG Wei, XU Ruiduo, YI Qi, WANG Xiaofang. Influence of re-entrant jet strength on cavitation characteristics of hydrofoil. Journal of Drainage and Irrigation Machinery Engin, 2016, 34(11): 921-926.
[1]SINGHAL A K, ATHAVALE M M, Li H, et al. Mathematical basis and validation of the full cavitation model[J]. Journal of fluids engineering, 2002,124(3):617-624.[2]ZWART P J, GERBER A G, BELAMRI T. A two-phase flow model for predicting cavitation dynamics[C]//Proceedings of ICMF 2004 International Conference on Multiphase Flow.Yokohama,Japan:[s.n.], 2004,152:1-11.[3]SCHNERR G H, SAUER J. Physical and numerical modeling of unsteady cavitation dynamics[C]//Procee-dings of 4th International Conference on Multiphase Flow. New Orleans, US:ICMF, 2001.[4]COUTIER-DELGOSHA O, FORTES-PATELLA R, REBOUD J L. Evaluation of the turbulence model influence on the numerical simulations of unsteady cavitation[J]. Journal of fluids engineering, 2003,125(1):38-45.[5]SAITO Y, TAKAMI R, NAKAMORI I, et al. Numerical analysis of unsteady behavior of cloud cavitation around a NACA0015 foil[J]. Computational mechanics, 2007,40(1):85-96.[6]刘艳, 赵鹏飞, 王晓放. 两种空化模型计算二维水翼空化流动研究[J]. 大连理工大学学报, 2012,52(2):175-182. LIU Yan, ZHAO Pengfei, WANG Xiaofang. Study of cavitating flows around two-dimensional hydrofoil using two cavitation models[J].Journal of Dalian University of Technology, 2012,52(2):175-182.(in Chinese)[7]季斌, 洪方文, 彭晓星. 二维水翼非定常空泡流数值模拟[J]. 舰船科学技术, 2009,31(1):128-133. JI Bin, HONG Fangwen, PENG Xiaoxing. Numerical simulation of unsteady cavitating flows around a two-dimensional hydrofoil[J]. Ship science and technology, 2009,31(1):128-133.(in Chinese)[8]LE Q, FRANC J P, MICHEL J M. Partial cavities: global behavior and mean pressure distribution[J]. Journal of fluids engineering, 1993,115(2):243-248.[9]STUTZ B, REBOUD J L. Measurements within unsteady cavitation[J]. Experiments in fluids, 2000,29(6):545-552.[10]BARRE S, ROLLAND J, BOITEL G, et al. Experiments and modeling of cavitating flows in venturi: attached sheet cavitation[J]. European journal of mechanics-B/fluids, 2009,28(3):444-464.[11]DULAR M, BACHERT R, SCHAAD C, et al. Investigation of a re-entrant jet reflection at an inclined cavity closure line[J]. European journal of mechanics-B/fluids, 2007,26(5):688-705.[12]韦喜忠, 洪方文, 彭晓星. 二维水翼云状空泡特性及其生成机理研究[C]//七届更迭 三十回眸——第七届船舶力学学术委员会全体会议论文集. 成都: 船舶力学学术委员会、《中国造船》编辑部, 2010:294-301.[13]时素果, 王国玉, 王复峰, 等. 绕三维水翼云状空化现象的实验研究[J]. 应用力学学报, 2011,28(2):105-110. SHI Suguo, WANG Guoyu, WANG Fufeng, et al. Experimental study on unsteady cavitation flows around three-dimensional hydrofoil[J]. Chinese journal of applied mechanics, 2011,28(2):105-110.(in Chinese)[14]FRANC J P. Partial cavity instabilities and re-entrant jet[C]//Proceedings of 4th International Symposium on Cavitation. Pasadena, USA: California Institute of Technology, 2001:1-21.[15]陆鹏波. 高温高压混流泵空化及其对泵结构设计影响分析[D]. 大连:大连理工大学, 2012.[16]王巍,羿琦,林茵,等.水翼表面布置射流水孔抑制空化[J].排灌机械工程学报,2016,34(10):865-870. WANG Wei, YI Qi, LIN Yin, et al. Impact of hydrofoil surface water injection on cavitation suppression[J].Journal of drainage and irrigation machinery engineering,2016,34(10):865-870.(in Chinese)[17]SHEN Y T, DIMOTAKIS P E. The influence of surface cavitation on hydrodynamic forces[C]//Proceedings of American Towing Tank Conference, 22nd. St. John′s, Canada:[s.n.], 1989:44-53.