摘要
Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated due to aerodynamic interference between highway and railway decks. To study the effects of splitter plates, wind tunnel experiments for measuring VIV and aerostatic forces of twin decks under two opposite flow directions were conducted, while the surrounding flow and wind pressure of static twin decks with and without splitter plates are numerically simulated. The results showed that the incoming flow direction affects the VIV response and aerostatic coefficients. The highway deck has poor vertical and torsional VIV, and the VIV region and amplitude are different under different directions. While the railway deck only has vertical VIV when located upstream. The splitter plates can impede the process of vortex generation, shedding and impinging at the gap between twin deck, and significantly reducing the surface fluctuating pressure coefficient, thus effectively suppressing the VIV of twin decks. While, the splitter plates hurt the upstream deck regarding static wind stability and have little effect on the downstream deck. The splitter plates of appropriate width are recommended to improve VIV performances in twin parallel bridges.
在主梁两侧安装分流板是抑制其涡激振动的一种有效气动措施,而气动干扰效应使大跨公铁双幅桥的风振响应更为复杂。为了研究分流板对大跨公铁双幅主梁涡振和静力特性的影响,本文通过风洞试验测试了在两种相反来流下,公路和铁路主梁的涡激振动和静力特性,研究了不同宽度分流板对双幅主梁静力系数和涡激振动响应的影响,同时结合数值模拟的方法对比了有、无分流板时公铁双幅主梁绕流和表面风压特性,进一步讨论了分流板抑振的机理。结果表明,公路主梁竖弯和扭转涡振性能较差,而铁路桥面仅在上游位置发生竖弯涡激振动现象,公铁双幅主梁间存在明显气动干扰效应,来流方向显著影响公铁双幅桥涡振性能和静力系数;分流板对双幅桥涡振响应有明显的抑制效果,可以阻碍公铁双幅桥间隙内涡旋生成、脱落和冲击下游主梁的过程,显著降低主梁表面脉动压力系数,从而有效抑制公铁双幅桥涡振现象。同时,宽度较大的分流板对上游桥面的静风稳定性产生不利影响,对下游桥面影响有限。推荐使用适当宽度分流板来改善大跨公铁双幅桥的涡振性能。
基金
Projects(51925808,52078504,51822803) supported by the National Natural Science Foundation of China
Project(2022JJ10082) supported by the Natural Science Foundation of Hunan Province,China
Project(N2022Z004) supported by the Research on Technology Development Trend and Key Common Problems in Railway,China
Project(Xplorer Prize 2021) supported by the Tencent Foundation,China。
作者简介
Corresponding author:LIU Lu-lu,PhD Candidate,E-mail:liululu2020@csu.edu.cn,ORCID:https://orcid.org/0000-0001-9002-1873。
