轴对称自然空泡脉动特性水洞实验  

Water tunnel experiment of the pulsation characteristics of axisymmetric natural cavitation

作　　者：屠江锋 马少杰[1] 张合[1] TU Jiangfeng;MA Shaojie;ZHANG He(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院,江苏南京210094

出　　处：《哈尔滨工程大学学报》2019年第1期126-131,共6页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51275248)

摘　　要：为解决自然空化形成的空泡脉动特性问题,本文根据空泡压力微震方程,得出了空泡稳定条件。通过采用钝头体模型进行了水洞自然空化实验及高速摄影;同时利用压力变送器以及微型水压传感器采集了水压信号,对信号进行小波变换和快速傅里叶变换,并对比不同工况下的水压信号,从而对信号的频域和幅值进行了分析。结果表明:空泡的脉动主要是由尾部泡体脱落引起的;所采集到的水压信号具有宽频的特性,而高频分量主要由空泡界面上的气泡云破碎、水流中的游离小空泡破碎和湍流脉动所引起。本文的结果可为超空泡的稳定性研究提供一定的参考,有助于更好地掌握超空泡技术,为工程实践提供数据支撑。In order to solve the problem of cavitation fluctuation characteristics caused by natural cavitation.According to the microcavity pressure equation,the stability condition of a bubble is given by a blunt body model in the tunnel natural cavitation experiment.By high-speed photography,we use a pressure transmitter and a micropressure sensor to collect hydraulic pressure signal and conduct wavelet and fast Fourier transform on the collected signals.We also compare the hydraulic pressure signals under different working conditions and analyze the signal-frequency domain and amplitude.Results show that the pulsation of the cavitation bubble is mainly caused by the tail cavity′s falling off.The collected signal is characterized by a wide frequency range,and the high-frequency component is mainly generated by the breakup of the bubble cloud on the bubble interface and the breakup of the free small bubbles in the water flow and the turbulent fluctuation.The results can provide references for study of the stability of supercavitation to better understand the supercavitation technology and establish data support for engineering practice.

关 键 词：钝头体模型 自然空泡 空泡稳定性 水洞实验 压力变送器 水压信号 小波分析 脉动特性 

分 类 号：TV131.2[水利工程—水力学及河流动力学]