表面粗糙度对圆柱体涡激振动响应特性影响数值研究

摘要

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.