基于动力学模态分解的方柱绕流非定常流场分析  

UNSTEADY FLOW FIELD ANALYSIS FOR FLOW AROUND SQUARE CYLINDER UPON DYNAMIC MODE DECOMPOSITION

作　　者：刘士杰 张珍 刘庆宽 LIU Shi-jie;ZHANG Zhen;LIU Qing-kuan(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province,Shijiazhuang 050043,China)

机构地区：[1]石家庄铁道大学土木工程学院,石家庄050043 [2]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,石家庄050043 [3]河北省风工程和风能利用工程技术创新中心,石家庄050043

出　　处：《工程力学》2024年第S01期326-331,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(12202291);河北省高等学校科学技术研究项目(BJK2024177);河北省自然科学基金创新研究群体项目(E2022210078);河北省高端人才项目(冀办[2019]63号);河北省研究生创新资助项目(CXZZSS2023079)。

摘　　要：具有方形断面的结构或构件广泛应用于实际工程中,针对方柱绕流风荷载和风致振动特性开展研究至关重要。方柱绕流的尾流效应往往涉及多种复杂流动现象,捕捉其流动主要模态对深入分析流场特性以及流动控制具有重要意义。该文基于动力学模态分解(Dynamic Mode Decomposition,DMD)方法建立了能够提取流场主要模态并进行流场重构的降阶模型。基于数值模拟获取非定常流场快照;利用DMD进行主要模态提取;基于提取的主要模态对非定常流场进行重构。结果表明:DMD方法提取的前4阶模态能够准确重构原始流场,为流动控制和结构设计提供参考。Structures with square cross-sections are widely used in engineering,thusly it is important to investigate the wind loading and wind-induced vibration characteristics of the flow around one square cylinder.The unsteady flow field of flow around the square cylinder usually involve a variety of complex flow phenomena.It is significant to capture the main modes of flow for the analysis of the flow field characteristics and the control of flow.In this study,a Reduced Order Model(ROM)is established upon the Dynamic Mode Decomposition(DMD)method to extract the main modes of the flow field and to reconstruct the flow field.The snapshots of the unsteady flow field are obtained upon numerical simulations.The main modes are extracted using DMD.The extracted modes are utilized to reconstruct the unsteady flow field.The results show that the first fourth modes extracted by the DMD method can accurately reconstruct the original flow field and provide a reference for flow control and structure design.

关 键 词：动力学模态分解 方柱绕流 数据驱动 非定常流动 降阶模型 

分 类 号：O357.5[理学—流体力学]