Abstract:
In order to study the effect of vertical turbulence scale on the spatial distribution characteristics of buffeting lift in a streamlined box girder, a rigid section model pressure test is carried out. In this paper, three types of flow fields with obvious differences in vertical turbulence integral scale are selected to study the effect of dimensionless scale
Lw/
B (ratio of the vertical turbulence scale to the structure width) on the three-dimensional characteristics of buffeting lift. A generalized three-dimensional buffeting lift model of a streamlined box girder is proposed considering the three-dimensional effect of turbulent flow. The results show that
Lw/
B is the key control parameter in determining the three-dimensional buffeting lift characteristics of the streamlined box girder section. It is observed that the three-dimensional turbulence effect of the bridge becomes mire significant when
Lw/
B decreases. Meanwhile, the flow separation of the airflow on the windward side of the streamlined box girder section is significantly reduced with the use of aerodynamic measures, such as the nozzle and the inclined web. Therefore, the two-dimensional aerodynamic admittance of the buffeting lift of the streamlined box girder remains unchanged under different vertical turbulence scales, which indicates that the effect of the vertical turbulence scale on the high-frequency distortion of the buffeting lift load of the bridge can be ignored, and it can provide a reference for optimization of the aerodynamic shape of streamline box girder section structure.