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为研究既有桥梁对近桥位复线桥的气动干扰,选取不同梁高典型断面,采用增强壁面处理(EWT)的数值模拟方法,对比研究了主梁断面高度、来流风攻角及风向等因素对错列双钝体断面间的气动特性影响,并对其流场结构进行了分析。研究结果表明:受既有桥梁影响,复线桥主梁断面在位于迎风向和背风向时,三分力系数与单幅断面差异显著。对于不同梁高情况,复线桥监测断面位于背风向时,迎风侧腹板负压区随遮挡面积的增大而增大,扭转效应更为明显,升力方向随梁高变化发生改变;对于不同来流攻角情况,背风向监测断面在负攻角下所受阻力较对应正攻角略大,攻角增大引起了断面间大涡的破裂。断面形状、高度、遮挡面积及来流攻角均在不同程度上引起绕流特性的改变。
In order to study the aerodynamic interference of the existing bridge to the bridge double-track bridge, the typical section with different height of the girder is selected and the numerical simulation method of enhanced wall treatment (EWT) is adopted to study the relationship between the section height of the main girder, The influence of the aerodynamic characteristics between the double-bluff body and the bluff body was analyzed and the flow field structure was analyzed. The results show that the influence of the existing bridge, the section of the main girder of the double-track bridge, when located in the upwind and leeward directions, the difference between the third component coefficient and the single section is significant. For different beam height, when the monitoring section of double-tracked bridge is located in the leeward direction, the negative pressure area of the windward side web increases with the increase of occluding area, the twisting effect is more obvious, and the direction of lift changes with the variation of beam height. Flow angle of attack, the leeward to the monitoring cross-section of the negative angle of attack suffered resistance than the corresponding positive angle of attack slightly larger angle of attack caused by large cross-section of the large vortex rupture. Section shape, height, occlusion area and the flow angle of attack are to varying degrees, causing the flow around the characteristics of change.