当前位置: X-MOL 学术J. Wind Energy Ind. Aerod. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Effects of leading-edge separation on the vortex-induced vibration of an elongated bluff body
Journal of Wind Engineering and Industrial Aerodynamics ( IF 4.2 ) Pub Date : 2021-01-11 , DOI: 10.1016/j.jweia.2020.104500
Guiyue Duan , Shujin Laima , Wenli Chen , Hui Li

Wind-tunnel experiments were conducted to investigate the effects of leading-edge separation on the vortex-induced vibration (VIV) of an elastically-supported elongated bluff body. Solid wind barriers of various heights were fixed in the leading edge to adjust the flow separation. The vibration signals and the flow field information are acquired simultaneously by a laser-displacement system and particle image velocimetry (PIV) instrument respectively. The result shows that the VIV is excited by consecutive vortices shedding from the leading-edge shear layer. There is a critical height-to-thickness ratio (h/t)critical=0.4, the VIVs are observed when h/t0.4, while they are suppressed owing to the insignificant leading-edge separation when h/t<0.4. Three types of VIV are found, two of them are torsional VIV while another one is vertical VIV, which are named T1, T2, and V1 respectively. By placing a wake splitter plate at the trailing edge, V1 is suppressed entirely, T1 is weakened despite the slightly lower amplitude, while T2 transits to limit-cycle oscillations. The flow field information shows that the evolution and shedding pattern of leading-edge vortices vary from mode to mode. The status of the upper-layer leading-edge separated layer significantly affects the formation and the shedding of the trailing-edge vortices. The results reveal that leading-edge separation can play a dominant role in the vortex-induced vibrations of elongated bluff bodies.



中文翻译:

前沿分离对细长钝体的涡激振动的影响

进行风洞实验以研究前沿分离对弹性支撑的细长钝体的涡激振动(VIV)的影响。各种高度的固体挡风玻璃都固定在前缘中,以调节分流。振动信号和流场信息分别由激光位移系统和粒子图像测速仪(PIV)同时获得。结果表明,VIV被前沿剪切层的连续涡旋激发。高度/厚度比很关键H/ŤC[R一世Ť一世C一种=0.4,在以下情况下会观察到VIV: H/Ť0.4,尽管由于微不足道的前沿分离而将它们抑制了, H/Ť<0.4。发现了三种VIV,其中两种是扭转VIV,另一种是垂直VIV,分别命名为T1,T2和V1。通过在尾缘处放置一个尾流隔板,V1会被完全抑制,尽管幅度稍低,T1也会被削弱,而T2过渡到极限循环振荡。流场信息表明,前沿涡的演化和脱落模式随模式的不同而不同。上层前缘分离层的状态显着影响后缘涡旋的形成和脱落。结果表明,前沿分离在拉长的钝体的涡激振动中起着主导作用。

更新日期:2021-01-11
down
wechat
bug