剪切来流下串列三圆柱横向振动响应机理研究  

The influence mechanism of crossflow vibration response of three tandem cylinders in shear flow

作　　者：谭潇玲 涂佳黄[1] 雷平 梁经群 邓旭辉[1] TAN Xiaoling;TU Jiahuang;LEI Ping;LIANG Jingqun;DENG Xuhui(College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China;Zhongye Changtian International Engineering Co.,Ltd.,Changsha 410205,China)

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105 [2]中冶长天国际工程有限责任公司,长沙410205

出　　处：《振动与冲击》2021年第20期89-99,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金(11602214);湖南省自然科学基金(2020JJ4568);湖南省教育厅科学研究优秀青年项目(18B079)。

摘　　要：基于四步半隐式特征线分裂算子有限元方法,对低雷诺数工况下串列布置三圆柱体结构的单自由度流致振动问题进行了数值模拟,并重点分析了雷诺数、剪切率以及折减速度这三个关键参数对三圆柱体横流向动力响应、流体力、相位、频谱特性以及尾流模态的影响。计算结果表明,随雷诺数的增加,三圆柱体结构的最大振幅值增大,且超过共振区间后中下游两圆柱体振幅值在不同剪切率工况下的差异明显增大。不同雷诺数工况下,三圆柱体结构的振幅曲线随剪切率呈现出阶段性变化。雷诺数的增加对下游圆柱体升阻力系数最大值的影响较大,而剪切率对结构表面受力的影响则主要集中于共振区间以及大折减速度范围内的升力系数均方根值。随着雷诺数和剪切率的增加,中下游两圆柱体相位差发生转变以及“相位开关”后出现的“下凹段”所对应的范围明显扩大。另外,横流向位移PSD曲线中频率的阶数以及主频所对应的能量值变化较大。在流体速度差以及惯性作用的影响下,三圆柱体结构的尾流模态呈现出较大的不规则性。The single-degree-of-freedom flow-induced vibration of three elastically mounted circular cylinders subjected to the planar shear flow in tandem arrangement at low Reynolds numbers was numerically investigated by using a semi-implicit characteristics-based split(CBS)finite element algorithm.The influences of some key parameters,such as Reynolds number(Re),shear ratio(k),and reduced velocity(U r)on the characteristics of transverse dynamic responses,hydrodynamic coefficients,phases,spectrums and wake modes of three circular cylinders with tandem arrangement were analyzed.The numerical results show that with the increasing of Re the maximum amplitudes of three cylinders increase and a great difference between the amplitude beyond the resonance regime of midstream and downstream cylinders under different shear ratios is observed.The vibration amplitude of three cylinders versus the shear ratio can be divided into several stages respectively under different Re.The maximum value of drag and life coefficients of the downstream cylinder are more sensitive to the increasing of Re,and the influence of k on the hydrodynamic coefficients of the midstream and downstream cylinders concentrates on the r.m.s.value of the lift coefficient in the resonance and greater reduced velocity regime.With the increasing of Re and k,the range of the phase switch and its subsequent recessed segment broadens obviously.Moreover,the order of the frequency in PSD of the lift coefficient and transverse displacement and the energy corresponding to the main frequency show a significant change.Affected by the incoming flow velocity difference and inertial effect,a large irregularity was observed in the wake modes of the three cylinders.

关 键 词：平面剪切来流 动力响应 流体力系数 相位阶段变化 尾流模态 

分 类 号：O357.1[理学—流体力学]