Study On Flow Control Of Vortex Induced Vibration Of Long-Span Bridge Based On Active Suction And Blowing

The bridge structure is developing in the direction of long span and soft stiffness,which has a direct impact on wind-induced sensitivity,so the wind resistance of the bridge is becoming an important factor in its safety control.Because of the subsidiary structure and bluff body characteristics of all kinds of bridge sections,it is possible for the main beam to have vortexinduced resonance at low wind speed.In order to ensure the structural safety and driving comfort of long-span bridges,an active flow suppression measure of vortex vibration based on active blowing and suction is studied.Aiming at this research purpose,this paper takes a typical streamlined box girder and typical bluff box girder as the research object,through the segmental model wind tunnel test and numerical simulation technology,the influence of flow suppression measures based on active blowing and suction on the vortex vibration performance of main girders of each section and its influence mechanism are studied.The main contents of this paper are as follows:(1)This paper briefly summarizes the development of modern bridges and several examples of vortex induced vibration.Under this research background,it summarizes the current methods of vortex induced vibration suppression at home and abroad,and expounds the advantages and disadvantages of these methods.In the field of active flow control,a vortex vibration suppression method based on active blowing and suction is proposed.On this basis,the research significance and main content of this paper are introduced.(2)Taking typical streamlined and bluff body box girders as the research objects,the vortex vibration performance of the main girder under different wind attack angles is tested by segmental model wind tunnel test.Under the adverse angle of attack,the active flow control measures based on active blowing and suction are adopted.By changing the different parameters of the flow control measures,the influence on the vortex vibration suppression effect of the main beam is studied and the parameters are analyzed.(3)The segmental model wind tunnel pressure test is carried out for several typical working conditions of active flow control measures.The influence mechanism of flow control measures based on active blowing and suction is explored by analyzing the mean value,root mean square,aerodynamic correlation coefficient and contribution coefficient of pressure coefficient under various working conditions.(4)The original section and several effective working conditions of typical streamlined box girder are numerically simulated,and the mechanism of active flow control measures is further expounded through pressure cloud diagram and vorticity diagram.