圆柱固结刚性分离盘结构振动风洞实验研究  

Wind tunnel experiments of the vibration response for the circular cylinder fixed connection with rigid splitter plates

作　　者：陈雯煜 梁盛平 王嘉松[1] CHEN Wen-yu;LIANG Sheng-ping;WANG Jia-song(MOE Key Laboratory of Hydrodynamics,Shanghai Jiaotong University,Shanghai 200240,China)

机构地区：[1]上海交通大学工程力学系,水动力学教育部重点实验室,上海200240

出　　处：《实验力学》2020年第4期567-576,共10页Journal of Experimental Mechanics

基　　金：国家自然科学基金项目(No.118722M)资助;国家科技重大专项子课题(2016ZX05028-001)。

摘　　要：分离盘作为常用的流动控制装置之一,对于固定圆柱旋涡脱落具有很好的抑制作用。但是,对于结构振动,固结刚性分离盘是否有类似的抑制作用及控制机制尚待深入研究。本文通过风洞实验,利用非接触式激光位移传感器,研究圆柱固结短分离盘后在“从静止开始”和“连续增加风速”这两种不同的初始条件下的结构响应。结果表明,附加分离盘后,与典型的涡激振动(Vortex-induced vibration, VIV)类似,结构的响应虽然仍然限定在一段风速范围内,但是其幅值比单圆柱VIV幅值大得多。当分离盘长度为0.25D(D为圆柱直径)时,结构响应与圆柱VIV类似,分为两个分支。当分离盘长度为0.4D、0.5D时,结构响应存在明显的迟滞现象,同时,响应会在达到最大振动幅值后突然消失。连续增加风速时,振动随约化速度增加而增强。与典型的涡激振动类似,可以发现明显的频率锁定现象,与典型驰振特性不同。通过FFT分析尾流速度频谱,可以发现,附加分离盘后,频谱中出现大量的高阶谐频成分,它们的出现可能与旋涡脱落模式有关。Splitter plates, serving as one of the most commonly used devices for flow control, can tremendously suppress the vortex shedding of fixed cylinder. However, whether splitter plates have the similar vibration suppressive effect on free oscillating cylinder needs further research and the control mechanisms are still unclear. In the present study, the vibration response for the cylinder fixed with short splitter plates is studied using the non-contact laser displacement sensor through wind tunnel experiment under two different initial conditions of “from rest” and “by increasing wind velocity continuously”, respectively. The results indicate that when the splitter plates are attached, the vibration response is limited in a range of wind velocities, similar to the typical VIV (Vortex-induced vibration) of bare cylinders, but the amplitude is much higher than that of typical VIV for the single cylinder. For the case of L/D=0.25 with L the length of splitter plates and the diameter of cylinders, the vibration response has two branches. For the cases of L/D=0.4 and 0.5, the vibration response would abruptly halt after reaching the peak, with the presence of the hysteretic loop. As the wind velocity increases continuously, the vibration can be enhanced. Similar to the typical VIV, the frequency locking phenomenon can be found, which shows different performance with the classical galloping. Besides, multiple harmonics can be found in the frequency spectrums of the wake velocity by the FFT analysis, and their appearance may be related to the vortex shedding modes.

关 键 词：分离盘 涡激振动 风洞实验 谐频 

分 类 号：O353.5[理学—流体力学]