附属柔膜对矩形柱扭转颤振影响的实验研究  

Experimental study on effects of attached flexible films ontorsional flutter of a rectangular cylinder

作　　者：杨双月 王汉封[1,2] 赵崇宇 YANG Shuangyue;WANG Hanfeng;ZHAO Chongyu(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center for High-speed Railway Construction Technology,Central South University,Changsha 410075,China;Department of Earth and Environmental Sciences,The University of Manchester,Manchester M139PL,United Kingdom)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]曼彻斯特大学地球环境科学学院,英国曼彻斯特M139PL

出　　处：《中南大学学报（自然科学版）》2023年第11期4472-4480,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52078505);湖南省自然科学基金资助项目(2022JJ30736)。

摘　　要：通过风洞实验,研究附属柔膜对宽厚比B/D=3的单自由度矩形柱体扭转颤振的控制效果。柔膜固定于矩形迎风侧两边缘,高度d=0.5D。在折减风速Ur=0~22条件下,测量有、无控制状态下的振幅、尾流频率和尾流结构等。研究结果表明:前沿柔膜能够显著提高模型颤振临界风速,并大幅度减小颤振振幅。控制工况中,Ur=12.8时模型仍未起振,而柔膜已发生大幅拍动,并显著削弱了尾流中周期性涡脱。尽管控制工况中颤振振幅明显减小,但颤振发生后尾流主导频率仍锁定于结构固有频率,类似于无控制情况。颤振发生后,控制工况中拍动的柔膜仍能明显削弱模型尾流中的前缘涡,并减小流体对结构的气动力和做功,从而最终起到了抑制颤振的效果。Wind tunnel experiments were conducted to study the effects of attached flexible films on the torsional flutter of a rectangular cylinder with cross-section ratio B/D=3.The flexible films with the height of 0.5D,were fixed at the two leading edges of the rectangular cylinder.The flutter amplitude,dominant wake frequency and near wake structure were measured for both uncontrolled and controlled cases,with the reduced velocity Ur ranging from 0 to 22.The results show that the flexible films significantly increase the critical flutter wind speed and suppress the vibration amplitude.In the controlled case,the flexible film flaps when Ur=12.8 before occurrence of flutter,which considerably weakens the periodic vortex shedding in the wake.Although the flutter amplitude is considerably reduced in the controlled case,its dominant vortex shedding frequency is still locked in the natural frequency of the structure,and similar to the uncontrolled case.When the flutter occurs,the flapping flexible films weaken the leading-edge vortex,and reduce the aerodynamic force and work done by the fluid,thus suppressing the flutter.

关 键 词：二维矩形柱 扭转颤振 柔膜 PIV实验 相平均 

分 类 号：TU971[建筑科学—建筑理论]