表面粗糙度对圆柱体涡激振动响应特性影响数值研究

Effects of surface roughness on vortex induced vibration features of a circular cylinder

使用数值模拟方法,研究了粗糙度对圆柱体涡激振动响应特性的影响,对不同粗糙度下圆柱体的涡激振动响应幅值、漩涡泄放频率、结构振动频率、锁定区间等参数进行了对比分析。分析结果表明:依据涡激振动响应幅值以及响应频率,可以将整个折合速度区间划分为4个区间:区间I、区间II、区间III以及区间IV。随着粗糙度的上升,圆柱体涡激振动响应最大值呈下降趋势。随着粗糙度的上升,锁定区域开始点呈缓慢提前的趋势,而锁定区域结束点则呈快速提前的趋势,因此整个锁定区域宽度会随着粗糙度的上升而逐渐变窄。

Effects of surface roughness on vortex-induced vibration（ VIV） characteristics of a circular cylinder were studied numerically. The cylinder’s VIV response amplitude,vortex-shedding frequency,structural vibration frequency and lock-in region under different surface roughnesses were analyzed contrastively. The numerical results showed that the whole reduced velocity interval can be divided into four regions including region I,region II,region III and region IV based on the cylinder’s VIV response amplitude and frequency; with increase in roughness,the maximum value of the cylinder’s VIV drops,the beginning point of the lock-in region slowly shifts to an earlier position while the lock-in region’s ending point quickly shifts an earlier one,the width of the lock-in region becomes gradually narrower.