不规则截面双柱式桥塔抗风性能研究

Study on Wind Resistance of Double Column Bridge Tower with Irregular Section

以实际工程为研究背景,采用CFD数值模拟方法分析了串列不规则截面桥塔的抗风性能。在不同风向角或间距比条件下,计算并对比了单个塔柱和双塔柱的气动力系数和斯托罗哈数,分析了双塔柱周围流场的时均压力和时均旋涡流线情况。结果表明:两个塔柱的阻力系数和斯托罗哈数相比单个塔柱均发生不同程度的降低。随着风向角的增大,单个塔柱和上游塔柱的阻力系数为降低趋势,而下游塔柱为上升趋势。斯托罗哈数对风向角和间距比的变化并不敏感。随着间距比增大,上游塔柱的阻力系数增大,逐渐接近单个塔柱。在间距比为4时,两个塔柱的阻力系数发生较大变化,斯托罗哈数达到最小值,此时两柱之间的大旋涡破裂,同时在两塔柱附近出现独立的旋涡。

Based on the practical projects,the wind resistance of the bridge tower with irregular section is analyzed by CFD numerical simulation.The aerodynamic coefficients and Strouhal numbers of single column and double column at different wind angles and spacing ratios are calculated and studied.The variation of time-mean pressure and time-mean vortex streamlines in the flow field near the double column are analyzed.The results show that the drag coefficient and Strouhal number of two tower columns are reduced to different degrees compared with that of a single tower column.With the increase of wind angle,the drag coefficient of single tower column and upstream tower column decreases,while the drag coefficient of downstream tower column increases.Strouhal number is not sensitive to changes in wind angle and spacing ratio.With the increase of the spacing ratio,the resistance coefficient of the upstream column increases and gradually approaches that of a single column.When the spacing ratio is 4,the drag coefficient of the two towers changes greatly,and the Strouhal number is the smallest.In this case,the large vortex between the two towers breaks,and an independent small vortex appears near the two towers.