Wake control of a bridge model based on periodic-wakeinstability at low Reynolds number
Three-dimensional spanwise-varying control,which is known to be related to periodicwake-instability(3D wake instability),has recently been reported as a highly efficient method to control vortex shedding.With the aim of suppressing Kármán vortex shedding and the underlying aerodynamic forces in a bridge model using three-dimensional spanwise-varying control,Floquet stability analysis was applied to determine the most unstable 3D instability of a period vortex shedding wake at low Reynolds numbers(ReB = 4000,6000,and 8000).The numerical results showed that there was only a single peak of Floquet multipliers ranging from 1H to 6H,with H being the height of the bridge model; additionally,all Floquet modes were found to be analogous to the Mode-A type.Subsequently,spanwise-varying passive vortex generators(PVGs),which can trigger 3D instability of a wake by activating pairs of streamwise counter-rotating vortical structures,were applied to implement wake control.Large eddy simulation was used to verify the wake control effects with PVGs arranged on the lower surface of the bridge model.The results showed that,overall,the case of λ/H = 2 yields improved control effects on the fluctuating aerodynamic forces.In addition,the PVG could effectively trigger and enhance the Mode-A-like flow pattern and suppress spanwise vortices.
Three-dimensional spanwise-varying control 3D wake instability Floquet stability analysis Bridge Passive vortex generator
Hongfu Zhang Dabo Xin Jinping Ou
School of Civil Engineering,Northeast Forestry University,Harbin,China School of Civil Engineering,Harbin Institute of Technology,Harbin,China;Key Lab of Structures Dynami
国际会议
The 7th World Conference on Structural Control and Monitoring(7WCSCM)(第七届结构控制与监测世界大会)
青岛
英文
1139-1144
2018-07-22（万方平台首次上网日期，不代表论文的发表时间）