考虑迟滞效应的圆柱体涡激振动分析研究  

Vortex-induced vibration of a cylinder considering hysteretic effect

作　　者：康庄 张立健 倪问池 

机构地区：[1]哈尔滨工程大学深海工程技术中心,哈尔滨150001

出　　处：《振动与冲击》2017年第24期220-229,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(51009033)

摘　　要：采用基于OpenFOAM的自编程PimpleDyMFoam求解器,结合Mental提出的SST k-ω湍流模型,对质量比为2.6的弹性支撑双自由度圆柱涡激振动进行数值模拟研究。数值模拟采用匀加速匀减速和匀速三种初始条件。研究表明:在"数值水池"中圆柱涡激振动出现了迟滞现象,数值模拟的迟滞区间为6≤Ur≤6.8,并在约化速度为6和6.8时,通过升力与位移关系捕获了"相位切换"。匀加速与匀减速条件能捕获到超上端分支,而匀速条件缺失上端分支。在Ur=6.8时,匀加速方式得到最大振幅1.4D,而采用不考虑迟滞效应的匀速条件时,圆柱最大振幅仅为0.85D。三种速度形式均发现锁定现象,但是锁定区间不同。匀加速与匀减速成功模拟出2T模式,匀速只模拟出2P模式。通过对比分析迟滞区域内尾涡变化规律,对迟滞机理进行了阐述。同时发现,采用较小加速度的匀加速初始条件,其相位切换发生延迟现象。Numerical simulation for vortex-induced vibration( VIV) of a 2-DOF cylinder with mass ratio of 2. 6 was conducted using the Pimple Dy MFoam solver based on Open FOAM and adopting the k-ω SST turbulent model proposed by Mental. Three initial conditions including constant acceleration,constant deceleration and constant speed were employed in simulation. The results showed that the hysteretic phenomenon appears in VIV of the cylinder in a "numerical water pool",the hysteretic interval is 6≤Ur≤6. 8; when Uris 6 or 6. 8,the phase switching phenomenon is captured through the relation between lift and displacement; constant acceleration and constant deceleration conditions can capture the super-upper branch,while constant speed condition misses the upper branch; when Ur= 6. 8,the constant acceleration condition can get the maximum amplitude 1. 4 D; when adopting constant speed condition without hysteretic effect,the maximum vibration amplitude of the cylinder is only 0. 85 D; three initial conditions all lead to locking phenomenon,but their locking intervals are different; with constant acceleration and constant deceleration conditions, 2 T mode is successfully simulated; with constant speed condition,only 2 P mode is simulated; through analyzing contrastively wakes' varying law in hysteretic region,the hysteresis mechanism is presented; when adopting constant acceleration initial condition with a smaller acceleration,the phase switching is delayed.

关 键 词：涡激振动 初始条件 迟滞现象 相位切换 

分 类 号：U674[交通运输工程—船舶及航道工程]