悬索桥双吊索尾流致涡激振动的大涡模拟  

Large eddy simulation of wake-induced vortex vibration of twin hangers of a suspension bridge

作　　者：赵燕[1] 林伟群 杜晓庆[1,2] 杨骁[1] 代钦[2,3] ZHAO Yan;LIN Weiqun;DU Xiaoqing;YANG Xiao;DAI Chin(Department of Civil Engineering,Shanghai University,Shanghai 200444,China;Aerodynamic Flow Control Research Center,Shanghai University,Shanghai 200072,China;Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学土木工程系,上海200444 [2]上海大学风工程和气动控制研究中心,上海200072 [3]上海大学上海市应用数学和力学研究所,上海200072

出　　处：《振动与冲击》2019年第16期129-136,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51578330);上海市自然科学基金(14ZR1416000)

摘　　要：双吊索在大跨度悬索桥上应用广泛,在强/台风作用下,下游吊索常发生尾流激振。采用大涡模拟法,对雷诺数为1×10^4~4×10^4的串列双圆柱尾流致涡激振动进行数值模拟,研究了振动特性和流场流态随折减风速的变化规律,探讨了下游圆柱的动力响应、绕流场特性以及气动力三者之间的耦合关系,分析了尾流致涡激振动的流场干扰机理。结果表明:大涡模拟结果与风洞试验结果吻合良好,在某些折减风速范围内,下游圆柱会发生较大幅度的尾流致涡激共振;在下游圆柱的横风向振幅逐渐增大过程中,位移的瞬时相位领先于升力,在一个振动周期内升力对下游圆柱做正功,而位移与升力之间的相位差则逐渐增大;当发生涡激共振时,上游圆柱的尾流对下游圆柱有两种干扰形式:当下游圆柱偏离平衡位置时,从上游圆柱脱落的旋涡与下游圆柱的剪切层发生相互作用;而当下游圆柱在平衡位置附近时,上游圆柱的旋涡会撞击到下游圆柱迎风面。Twin hangers are used extensively in long-span suspension bridges.The downstream cables usually suffer wake-induced vibrations under strong wind or typhoon.Wake-induced vortex vibration of two tandem circular cylinders was numerically investigated by using a large eddy simulation(LES)method with Reynolds number from 1×10^4 to 4×10^4.The vibration characteristics and the variations of flow pattern with reduced wind velocity were studied.The coupling relationship of the dynamic response,the flow pattern and the aerodynamic for the downstream cylinder were discussed.Results show that the simulation results are in reasonable agreement with the wind tunnel test.At a certain reduced wind velocity,the downstream cylinder undergoes wake-induced vortex vibration at the largest magnitude.As the amplitude of the downstream cylinder increasing,the instantaneous phase of the displacement is ahead of that of the lift force and the lift does positive work in one cycle of the oscillation,and the phase difference between the displacement and the lift is gradually increased accordingly.Furthermore,the interactions between the wake of the upstream cylinder and the downstream one have two different ways,one is the vortice shed from the upstream cylinder interacting with the shear layer of the downstream cylinder while the downstream cylinder deviates from the equilibrium position,the other is the upstream vortice impinging on the windward surface of downstream cylinder while the downstream cylinder is near the equilibrium position.

关 键 词：悬索桥 双吊索 尾流激振 涡激振动 大涡模拟(LES) 干扰机理 

分 类 号：O351.2[理学—流体力学]