斜向水流对圆端形墩紊流宽度的影响分析

An analysis of the impacts of oblique flow on the turbulent width of round-ended piers

通过flow-3D数值模拟的方法,研究斜流条件下紊流宽度的取值标准。当水流流向与桥轴线法线方向存在夹角时,桥轴线方向的横向流速由2部分构成:一部分来自斜流,另一部分来自桥墩影响。此时不宜直接以横向流速为0.3m/s作为紊流宽度的取值标准,可采用有(无)桥墩时横向流速差值为0.3m/s作为取值标准。以桥轴线方向为横向流速的方向,紊流区的宽度随着水流流向与桥轴线夹角的增加而增加。在一定范围内,圆端桥墩两侧的紊流宽度和总紊流宽度都随墩长的增加而增加,在墩长相同的情况下,紊流宽度随着来流方向与桥轴线法线夹角的增大而增大。

The chosen value standard of turbulent width under oblique flow is studied by using flow-3D numerical simulation method.When a certain angle between the direction of flow and the normal of bridge axis exists, transverse velocity of the direction of bridge axis is composed of two parts, one from oblique flow,the other from the impact of piers. For this moment,it＇s improper to take the transverse velocity of 0.3 m/s as the chosen value standard of the turbulent width directly,a fixed difference of 0.3 m/s of the transverse velocity with or without the presence of the piers can be adopted.To regard the direction of bridge axis as the direction of transverse velocity, the width of turbulent region increases as the angle between flow direction and bridge axis increases.Within a certain range, the turbulent width on both sides of the round-ended piers and the total turbulent width increase with the extension of the length of piers.If the length of the piers is the same, the turbulent width increases as the angle between flow direction and the normal of bridge axis increases.