基于动态模态分解的空化流动特性研究  

Study on cavitation flow characteristics based on dynamic mode decomposition

作　　者：张芮菡 李凯林 刘刚[1] 郝宗睿 ZHANG Ruihan;LI Kailin;LIU Gang;HAO Zongrui(Institute of Oceanographic Instrumentation,Qilu University of Technology(Shandong Academy of Sciences),Qingdao 266100,China)

机构地区：[1]齐鲁工业大学(山东省科学院)山东省科学院海洋仪器仪表研究所,山东青岛266100

出　　处：《齐鲁工业大学学报》2025年第1期1-8,共8页Journal of Qilu University of Technology

基　　金：国家自然科学基金项目(52106202);山东省重点研发计划项目(2021CXGC010705)。

摘　　要：水动力空化技术逐渐得到广泛应用,准确高效地提取空化云的结构特征有助于我们更好地理解空化内部机理。以高速摄像实验为手段,通过对空化云图像进行灰度值提取,揭示了射流振荡器中空化现象的特征。同时,引用动态模态分解(dynamic mode decomposition,DMD)方法对振荡器内部瞬态流场进行了深入探究,研究了振荡器空化云的相干结构和频率特性,进一步提取了不同的主导结构,并发现了与脱落频率下云空化的整体周期动力学关系。最后,通过DMD方法,准确提取了主频率和模态特性,发现振荡器的能量主要集中在前两个模态中,形成较大的相干结构,而高频模态包含较少的能量。该实验结果为进一步研究射流空化流动的机理提供了重要的实验和理论基础。Hydrodynamic cavitation technology is gradually gaining widespread application,and the accurate and efficient extraction of structural characteristics of cavitation clouds contributes to a better understanding of the internal mechanisms of cavitation.In this study,high-speed imaging experiments were conducted to reveal the characteristics of cavitation phenomena within a jet oscillator through grayscale value analysis.Additionally,the dynamic mode decomposition method(DMD)was employed to conduct an in-depth exploration of the transient flow field inside the oscillator,investigating the coherent structures and frequency characteristics of cavitation clouds within the oscillator.Furthermore,different dominant structures were extracted,and the overall cyclic dynamics relationship with cloud cavitation under shedding frequency was discovered.Finally,using the DMD method,this study accurately extracted the dominant frequencies and modal characteristics,revealing that the energy of the oscillator mainly concentrates in the first two modes,forming larger coherent structures,while higher-frequency modes contain less energy.These experimental results provide important experimental and theoretical foundations for further research into the mechanisms of jet cavitation flow.

关 键 词：水力空化 高速摄像 射流振荡器 灰度处理 动态模态分解 

分 类 号：TP6[自动化与计算机技术—控制理论与控制工程]