Aerodynamic Configuration Study Of Cable-Stayed Casing Based On The Purpose Of Damping

With the continuous development of modern bridge technology, the span of cable-stayed bridge is increasing gradually. The security issues of bridge become one of the important contents in the engineering field.As the main load-bearing components of cable-stayed bridge, cable-stayed is one of the most important influencing factors. It has important theoretical and practical significance to ensure the safety of cable-stayed bridge by reducing the vibration of cable-stayed.It includes two kinds of damping measures, mechanical damping measures and aerodynamic damping.In this paper, the latter is used by changing the cable cross-section shape to reduce the number of vortex which is caused by wind.flowing around cables, thereby affecting the form of the vortex shedding, reducing the fluctuating lift caused by the vortex shedding. Thus avoid coming into being significantly vibration to cable-stayed.The thesis brings forward three types of aerodynamic shape, and set up their speed and stress field simulation model, besides, defines the required equations of Computational Fluid Dynamics and boundary conditions. By making use of Finite Volume Method, CFD software FLUENT is used to simulate and calculate for model, the results that the distribution law of the flow field which the air flow around different sections of cables are obtained. In order to truly reflect flow field changes in practice, wind tunnel tests are carried out to the three design model, resulted in the actual and intuitional flow field distribution. Combined with previous simulation results, we compare the characteristics of flow field of the three aerodynamic model and analyze the advantages and drawbacks of each section form.Sum up the advantages of several models, we change a better aerodynamic shape. By changing the parameters of size and adding a transition curve to optimize the model, we put forword a new type of cross-section shape, and establish a relationship between the geometric shape. And then, we carry out simulation to the form and compare with the former of the aerodynamic model for the flow field distribution, analyze and explain the advantages of this form.