基于POD和DMD的60°交叉管绕流分析  

Analysis of flow past two circular cylinders crossing in 60 degrees based on POD and DMD

作　　者：张嶔[1] 杨青青 唐也婷 王天源 ZHANG Qin;YANG Qing-qing;TANG Ye-ting;WANG Tian-yuan(College of Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100

出　　处：《船舶力学》2024年第3期400-408,共9页Journal of Ship Mechanics

基　　金：国家自然科学基金资助项目(51979260);中国博士后科学基金资助项目(2019M652481)。

摘　　要：本文利用本征正交分解(Proper Orthogonal Decomposition,POD)和动力学模态分解(Dynamic Mode Decom⁃position,DMD)分析雷诺数Re=200时三维60°交叉管在间隙比G=4下的涡量数据,并探究尾涡的演变规律。分析结果表明:尾流场中的涡流尺度及重要程度随频率增加而减小,少数低频模态便可主导大尺度流动现象,而高频模态主要丰富尾流场中的小尺度湍流细节;上下游圆柱的涡结构以0.19 Hz的频率从两圆柱脱落,并在相同的频率下以平行形态向下游演变;上游圆柱脱落涡与下游圆柱的相互作用导致下游圆柱涡激振动明显,并产生多个高频升力频谱峰值。In this paper,to study the evolution pattern of wake vortices past two crossing cylinders in 60 de⁃grees arrangement at the gap ratio of G=4 and the Reynolds number of Re=200,proper orthogonal decomposi⁃tion(POD)and dynamic mode decomposition(DMD)were employed to analyze the magnitude vorticity data.The analysis results indicate that the spatial scale of wake vortices decreases with the frequency increasing.The large-scale flow phenomena in the wake can be approximately reconstructed by a few low-frequency modes,while high-frequency modes mainly enrich the small-scale turbulence details.Wake vortices shed from upstream and downstream cylinders at a frequency of 0.19 Hz and propagate toward downstream in par⁃allel morphology with the same frequency.The interaction of the vortex shedding from upstream cylinder on the downstream cylinder causes a significant vortex-induced vibration(VIV)on the downstream cylinder and results in multiple peaks in its lift coefficient spectrum.

关 键 词：降阶模型 交叉双管 尾涡 

分 类 号：TV131[水利工程—水力学及河流动力学]