附加开式平板叶片的圆柱流致旋摆响应数值研究  

Numerical investigation of flow-induced swinging response of circular cylinder with uniformly distributed detached flat blades

作　　者：唐涛 朱红钧 颜知音 王硕 刘红叶 Tao Tang;Hong-jun Zhu;Zhi-yin Yan;Shuo Wang;Hong-ye Liu(Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China;Natural Gas Purification Plant,PetroChina Southwest Oil and Gasfield Company,Chongqing 400021,China)

机构地区：[1]西南石油大学石油与天然气工程学院,成都610500 [2]中国石油西南油气田公司天然气净化总厂,重庆400021

出　　处：《水动力学研究与进展（A辑）》2022年第3期383-392,共10页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金(51979238);四川省青年科技基金(2017JQ0055)。

摘　　要：该文对Re=150时,附加开式平板叶片的圆柱流致旋摆响应进行了数值模拟,分析了叶片数量(n=1-5)对旋转模式、流场特性和水动力系数的影响。结果表明,结构调稳后,将围绕新的旋摆平衡位置往复摆动,该平衡位置和初始位置之间的夹角与叶片的数量有关。模拟发现了三种响应模式:(1)类静止模式(n=2和4),摆幅几乎为零,相较于单圆柱升力减小接近100%。但n=2和n=4的原因不同,n=2时,涡量带呈对称分布,圆柱后方存在更长的回流区;而n=4时,尾涡泄放的位置位于圆柱下游五倍直径处,对近尾迹区的影响小,后端上侧叶片后方出现了较长的回流区。(2)小幅摆动模式(n=1和3),n=1时,叶片旋转到圆柱后方,摆幅为3.723°,尾涡与裸柱没有明显差异;n=3时,前端叶片分割来流,后端两叶片对称分布,结构稳定性增强,摆幅减小为1.498°。圆柱表面的旋涡脱落被抑制,叶片上泄放的旋涡以双排涡的形式向下游迁移。(3)大幅摆动模式,n=5时结构摆幅达到15.575°,前端叶片上分离的边界层再次附着于后端叶片或圆柱,并与后端叶片及圆柱的剪切层共同作用,使得圆柱后方近尾流场更为复杂,旋涡的耗散及合并行为频发。从机械能的捕获角度出发,推荐附加叶片数量为1,此时系统获得较大的摆幅、较高的摆动频率且摆动周期性更强。此外,还以n=2为例,探究了初始位置(α=0-90°)对旋摆平衡位置与摆幅的影响,模拟发现旋摆平衡位置与初始攻角无关。当初始位置与平衡位置重合时,摆幅最小;当二者不重合时,转动引起旋涡不规则脱落,旋涡的融合位置提前,导致了摆幅的增大。The flow-induced swinging response of a circular cylinder with detached flat blades uniformly distributed around it is numerically investigated at Re=150.The effects of the number of blades on the swinging modes,flow characteristics and hydrodynamic coefficients are examined.The results indicate that the str ucture swings back and forth about a new equilibrium position after a transient stabilization of rotation.The angle between th e equilibrium position and initial one is related to the number of blades.Three swinging modes are identified according to the swinging amplitude.The first mode named quasi-static pattern occurs at n=2 and 4,where the amplitude is almost equal to zero an d the reduction in lift exceeds 99%compared to the bare cylinder.At n=2,two symmetrical vorticity bands and a long recirculation zone are found.The recirculation zone shifts to the rear of the upper blade at n=4.The vortex formation locates five times the diameter downstream of the cylinder,which has slight influences on the near-wake flow.The second mode is called small-amplitu de pattern.At n=1,the blade swings behind the cylinder with a small amplitude of 3.723°.The wake structure is similar to that of bare cylinder.At n=3,the front blade separates the oncoming flow and the rear two blades are symmetrically distributed with respect to the oncoming flow.The structural stability is enhanced and thus with a smaller amplitude of 1.498°.The vortex shed ding from cylinder surface is significantly suppressed.Instead,the vortices shed from the rear blades migrate downstream in a d ouble-row pattern.The large-amplitude mode occurs at n=5 where the swinging amplitude reaches up to 15.575°.The boundary layers separated from the front two blades reattach on the rear blades or cylinder again.The interaction of shear layers between th e blades and cylinder makes the near-wake flow more complex,leading to the frequent dissipation and merging of vortices.Fin ally,the cylinder with one blade is recommended as an effective energy harvester due to

关 键 词：流致旋摆 平板叶片 旋摆动能 边界层再附着 

分 类 号：O353.4[理学—流体力学]