Vortex-induced Vibration Control Of A Streamline Box Girder Using The Wake Perturbation Of Horizontal Axis Micro-wind Turbine

With the development of modern bridge developed,the long-span bridges are gradually for the direction of light,flexible,small damping and light mass.At the same time,the sensitivity of bridges about the wind was also increasing.Vortex induced vibration is a complex self-excited vibration,which often occurs to the low wind speed.When the frequency of vortex shedding is close to the natural frequency of the bridge,vortex-induced resonant responses of long-span bridges will occur,which will cause driving discomfort and fatigue damage of bridge.In this paper,a small horizontal axis wind turbine(HAWT)is used to generate downstream vortices to suppress the formation and development of the vortices.For exploring the installation a small horizontal axis wind turbine on the bridges.We take the measure of the wind tunnel test,numerical simulation and theoretical analysis to study the control effect on vortex induced vibration.The main research are as follows:(1)By exploring the theory of the 3D spanwise-varying control,the mechanism and feasibility of the small horizontal axis wind turbine in suppressing vortex induced vibration of long-span bridge are discussed.The wake characteristics of the wind turbine are observed by CFD simulation,and the control parameters of small wind turbine are proposed,such as blade,airfoil and tip speed ratio of the wind turbine.Based on these parameters,the installation and layout of the wind turbine are determined.(2)According to the similarity criterion of small wind turbine and the similarity theory of bridge aeroelastic model,the determination method of test parameters for the integrated test model of the bridge girder and wind turbine is proposed.In order to ensure the reliability of the wind tunnel model aeroelastic test results,the integrated wind tunnel test process is given by integrating the structural dynamic parameters and geometric parameters of the segmental model and the motion parameters and geometric parameters of the wind turbine.(3)Taking a typical long-span bridge as the research object,the wind tunnel test method of bridge segment model is used to compare the vortex induced vibration characteristics of bridge girder under different control parameters.It is verified that the small horizontal axis wind turbine can effectively suppress the vortex induced vibration of bridge,and the regularity between control parameters and control effect are obtained.It is found that the large-scale periodic vortex shedding of the bridge girder is almost completely suppressed under the wake disturbance action of the horizontal axis wind turbine,which makes the large-amplitude vortex induced resonance disappear...