基于涡动力学的大跨度桥梁风效应流动控制

Vortex dynamics-based flow control of wind effects on long-span bridges

主梁和拉/吊索是大跨度桥梁的关键结构构件,通常具有较小的刚度和阻尼比,在来流风作用下,易在结构尾部形成周期性旋涡脱落,进而诱发涡激振动等多种形式的风致振动.主梁和拉/吊索结构的风致振动会加重结构疲劳,甚至影响桥梁运营安全.因此,发展大跨度桥梁风振控制方法,不仅可以丰富大跨度桥梁空气动力学理论,还具有重要的理论意义和工程价值.本文从涡动力学出发,提出基于稳定吸/吹气的主、被动流动控制方法,消除主梁和拉/吊索结构尾流区的周期性旋涡脱落,实现减小非定常气动力与风致振动响应的控制目标.

Main girders and cable structures are critical components of long-span bridges and usually have relatively low stiffness and damping ratios.When they are subjected to incoming wind,periodic vortex shedding develops near the wake and causes wind-and vortexinduced vibration.Wind-induced vibration can lead to severe problems such as fatigue and corrosion,which can affect the bridge operation safety.Therefore,developing control methods for wind-induced vibration in long-span bridges will enrich the aerodynamics theory of large-span bridges and has important scientific significance and engineering value.The present study employs steady active/passive suction and blowing methods based on vortex dynamics to attenuate the periodic vortex shedding in the wake region of main girders and cable structures.The results indicate successful suppression of unsteady aerodynamic forces and mitigation of windinduced vibration.