平动与转动受迫谐振圆柱的水动力特性分析  

Hydrodynamic characteristics of laminar flow over a circular cylinder having forced rotational and transverse harmonic oscillations

作　　者：刘名名[1] 唐国强[1] 吕林[1] 滕斌[1] LIU Ming-Ming TANG Guo-Qiang LU Lin TENG Bin(State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 1160241)

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《振动与冲击》2017年第11期31-40,共10页Journal of Vibration and Shock

基　　金：国家重点基础研究发展计划(973计划)(2014CB046803);国家自然科学基金(51409035;51279029)

摘　　要：通过求解二维不可压缩黏性流体的Navier-Stokes方程,对低雷诺数下圆柱同时具有周期性旋转和横流向振动的流固耦合问题开展了数值分析研究。重点考察了不同强迫振动频率(f*([0.5,2.0])以及转动与平动之间的相位差(φ=±180°,±120°,±60°及0°)下,圆柱结构的受力特性、锁定模式及尾迹涡流场演化特征。数值分析结果表明,在周期性转动和平动的联合激励下,流动过程除存在常规的基本锁定(Primary Lock-in)现象外,还存在非线性准周期锁定(Quasi-periodic Lock-in)现象;旋转运动与横流振动之间的相位差φ对锁定形式及锁定的频率区间有重要影响,对称的正负相位差可导致高度一致或截然不同的锁定形式;两自由度谐振圆柱的水动力系数在锁定条件下会发生明显跳跃,总体上随强迫振动频率的增大而增大;对于特殊的准周期锁定情况,尾迹区内存在涡旋结构的多级次非线性分叉行为,尾涡演化过程遵循准周期特性。Based on the two-dimensional finite element solution of incompressible viscous Navier-Stokes equations in the frame of Arbitrary Lagrangian-Eulerian （ALE） method, the hydrodynamics of laminar flow over a circular cylinder with combined forced harmonic rotational and transverse oscillations are examined. The effects of oscillatory frequency （f＊ [0.5, 2.0] with an interval of 0.05） and phase difference between the rotation and translation motions （φ=±180°, ±120°, ±60° and 0°） on the fluid forces, lock-in characteristic and wake mode are presented. Two distinct lock-in modes are identified for the present two-degree-of-freedom forced oscillations, namely the ordinary primary lock-in and the nonlinear quasi-periodic lock-in. The phase difference has profound influence on the type of lock-in and the corresponding lock-in regime. Two opposite phase difference can result in highly consistent or quite different lock-ins. The fluid forces on the circular cylinder generally increase with the oscillating frequency, and the hydrodynamic jumps can be observed. For the specific quasi-periodic lock-in with five forced oscillatory periods, double or triple vortex splits in three different stages are involved in the evolution of wake flow, which are consistent with the essence of quasi-periodic oscillation.

关 键 词：圆柱 旋转振动 横流向振动 准周期锁定 尾涡模式 

分 类 号：P751[交通运输工程—港口、海岸及近海工程]