摘要
针对螺旋桨、水轮机以及导管桨等叶片的梢涡空化现象,国内外学者开展了一系列相关实验研究。本文对梢涡空化起始(或初生)、发展与溃灭(或消失)等3个阶段的实验研究进展及成果进行综述,梳理未来的研究方向及关键问题,为梢涡空化研究提供参考。关于梢涡空化初生问题,基于旋涡理论模型及流场测量技术,对不同翼型的梢涡结构特征进行分析,根据空化发生的相变条件(即气核、低压以及低压作用时间),初步认识了梢涡空化发生机理;关于梢涡空化发展问题,以辐射噪声骤增为典型特征,借助空泡图像的高速摄影及声学信号同步采集技术,研究梢涡空化形态及对应的辐射噪声特征,通过进一步解释“涡唱”现象,深入认识了梢涡空化发生机理;关于梢涡空化溃灭问题,溃灭发生位置一般远离桨叶等水力机械,对结构物的振动与剥蚀影响很小,本文不作详细阐述。此外,对梢涡空化初生的准确预报,一直是相关理论研究成果应用于工程实际所面临的一个重要问题。归根结底,主要是影响梢涡空化关键参数(比如载荷、雷诺数和水质等)的尺度效应问题和梢涡空化初生预报公式逐渐完善的问题。
As a typical vortex cavitation phenomenon,Tip Vortex Cavitation(TVC)occurring on the propellers(or duct propellers)and hydro-turbines has been widely investigated in experiments.To figure out the research orientations and the key problems in the near future,experimental research progress and results about the three stages of TVC,that are inception,development and collapse,are summarized to provide reference for further studies.On the inception of TVC,analysis of vortex dynamics of the tip flow field is conducted to get preliminary acquaintance with mechanics of its inception under various phase transformation conditions of bubble nuclei,low pressure and action time of low pressure,based on vortex theoretical models and experimental measurement technology.On the development of TVC characteristiced by a sharp increase of the radiation noise,research on the morphology of TVC and characteristics of the corresponding radiation noise is carried out for a better understanding of the mechanism of the development and radiation noise of TVC,in combination of high-speed photography of the morphology and acoustic signal acquisition of TVC.The collapse of TVC is only mentioned briefly,because few attention is paid to this issue as it can hardly cause vibration and erosion on hull structures.An accurate prediction of the inception of TVC in practice is still an open question though some progress is made in the fundamental research of TVC.How to quantify the scale effect of the vital parameters,such as load,Reynolds number and water quality,and how to improve the incipient prediction formula of TVC are problems still to be solved.
作者
刘玉文
徐良浩
宋明太
顾湘男
彭晓星
LIU Yuwen;XU Lianghao;SONG Mingtai;GU Xiangnan;PENG Xiaoxing(National Key Laboratory on Ship Vibration and Noise,China Ship Scientific Research Center,Wuxi Jiangsu 214082,China)
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2020年第5期1-11,共11页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金(11772305,91852101)。
关键词
水翼
梢涡
空化
辐射噪声
流动显示
hydrofoil
tip vortex
cavitation
radiation noise
flow visualization
