基于CFD的大跨度邻近桥梁气动干扰效应分析

Aerodynamic Interference Effect Between Long Span Adjacent Bridges Based on CFD

为研究大跨度邻近桥梁的气动干扰效应,本文以2座大跨度桥梁为对象,基于CFD(Computational Fluid Dynamics)数值模拟研究不同间距比和风攻角下气动干扰效应对静力三分力系数的影响,以及不同间距比和折算风速对颤振导数的影响。结果表明:上游桥梁三分力系数及下游桥梁力矩系数对气动干扰效应不敏感;气动干扰效应对下游桥梁的阻力系数和升力系数的影响与间距比和风攻角有关;下游桥梁颤振导数受气动干扰效应影响大,随间距比与折算风速的变化表现出不同的规律。

Two long span bridges were taken as the examples to study the aerodynamic interference effect between long span adjacent bridges. The influence of different spacing ratios and wind attack angles on the aerodynamic coefficients and the influence of different spacing ratios and reduced wind speeds on the flutter derivatives were explored based on CFD( Computational Fluid Dynamics) numerical simulation. The results show that the aerodynamic coefficients of the upwind bridge and the moment coefficient of the downwind bridge are insensitive to the aerodynamic interference effect. The influences of aerodynamic interference effect on the drag coefficient and the lift coefficient of the downwind bridge are related to the spacing ratio and the wind attack angle. The flutter derivatives of the downwind bridge are affected greatly by the aerodynamic interference effects,which perform different rules with the change of spacing ratio and reduced wind speed.