变攻角双圆柱涡激振动响应研究  

Study on vortex induced vibration of doublecylinders with variable angle of attack

作　　者：张居正 姜新佩[1] 柏茜 ZHANG Juzheng;JIANG Xinpei;BAI Xi(College of Water Resources and Hydropower,Hebei University of Technology,Handan 056038,Hebei,China)

机构地区：[1]河北工程大学水利水电学院,河北邯郸056038

出　　处：《水利水电技术（中英文）》2021年第9期67-77,共11页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划项目(2018YFF0300201)。

摘　　要：为了研究双圆柱在变攻角下的涡激振动机理,基于CFD(Computational Fluid Dynamics)耦合动力学及嵌套网格方法,建立了双自由度圆柱体涡激振动的高保真数值模型。通过与国内外实验数据对比,验证了数值模型及程序的准确性。然后,对雷诺数Re=0~8000、约化速度U r=2~13、来流攻角θ=0°~90°下圆柱体的振动响应、流体力特性、尾流模式开展了研究。仿真结果表明:当约化速度U r=2~3时,随着来流攻角增加,上下游柱体横向位移差不断增大,柱体尾流模式经历了单钝体、2S(双单涡模式)、2S(同相同步或反相同步模式)的演变过程,此时柱体振幅较小;当U r=4~8时,上下游柱体进入锁定区间,振幅均达到最大。与大攻角(θ=60°~90°)不同,由于小攻角下(θ=0°~30°)柱间存在较强的涡融合效应,相应的振幅较大些。特别的,受柱间屏蔽作用控制,小攻角下柱体最大振幅开始于更大的约化速度;当U r=9~13时,大攻角下上下游柱体均脱离锁定区间,振幅与单圆柱趋于一致。相反,小攻角下柱体振动频率接近漩涡脱落频率,加之上游柱体尾流的单边促进作用,导致上下游柱体振幅一直处于较大值。研究结果可为相关海洋工程设计提供参考。In order to study the mechanism of VIV(vortex induced vibration)of a double cylinder at different angles of attack,a high fidelity numerical model of VIV of a cylinder with two degrees of freedom was established based on CFD(Computational Fluid Dynamics)coupled dynamics and overset grid method.The accuracy of the numerical model and program is verified by comparing with the experimental data at home and abroad.Then,the vibration response,hydrodynamic characteristics and wake mode of the cylinder with Reynolds number Re=0~8000,reduced velocity U r=2~13 and angle of attackθ=0°~90°are studied.The simulation results show that:when the reduced velocity U r=2~3,the lateral displacement difference between the upstream and downstream cylinders increases with the increase of the angle of attack of the incoming flow,and the wake mode of the cylinder undergoes the evolution process of single bluff body,2S(double single vortex mode)and 2S(in-phase synchronous or inverse synchronous mode),and the amplitude of the cylinder is small;when U r=4~8,the upstream and downstream cylinders enter the locking range,and the amplitude reaches the maximum.Different from high angle of attack(θ=60°~90°),the amplitude is larger due to the strong vortex fusion effect between cylinders at low angle of attack(θ=0°~30°).Especially,under the control of the shielding effect between the columns,the maximum amplitude of the cylinder starts at a larger reduced velocity at a small angle of attack;when U r=9~13,the upstream and downstream cylinders at a large angle of attack are out of the locking range,and the amplitude tends to be the same as that of a single cylinder.On the contrary,the vibration frequency of the cylinder at small angle of attack is close to the vortex shedding frequency,and the unilateral promotion of the upstream cylinder wake leads to the large amplitude of the upstream and downstream cylinders.The research results can provide a reference for the relevant marine engineering design.

关 键 词：变攻角 涡激振动 嵌套网格 振动响应 流体力特性 尾流模式 

分 类 号：P751[交通运输工程—港口、海岸及近海工程] O353.4[天文地球—海洋科学]