孤立波边界对流线型箱梁静气动力系数的影响  

Effect of solitary wave boundary on aerostatic coefficients of a streamlined box girder

作　　者：张家玮 康啊真 祝兵[1] 薛世豪 吴超 ZHANG Jiawei;KANG Azhen;ZHU Bing;XUE Shihao;WU Chao(Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学桥梁工程系

出　　处：《铁道科学与工程学报》2019年第10期2497-2504,共8页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51178397);国家自然科学基金(青年)基金资助项目(51708456);四川省应用基础重大前沿项目(2017JY0003)

摘　　要：近海台风波浪的气动干扰可能对桥面标高较低的近海桥梁主梁的气动特性产生显著影响。为研究孤立波边界对流线型箱梁的气动力系数的影响,针对流线型箱梁进行一系列参数化的风洞试验,并运用CFD方法模拟波浪边界影响下的二维风场,与试验结果进行验证。系统分析波峰位置、桥下净空、攻角和波高等条件对主梁气动力系数的影响。通过CFD流场分析对气动力系数变化的可能机理进行讨论。研究结果表明:相较于无波浪条件,随着波峰从上风向靠近主梁,主梁的气动力系数呈先降低后升高的趋势,在下风向梁体附近气动力系数达到极值,此后随着波峰远离,气动力系数逐渐减小。这是由于波浪与梁截面之间局部流场方向和压强发生变化。在桥下净空小于2倍的桥宽范围内,气动力系数变化幅度随桥下净空的减小而增大,随波高的增大而增大。The aerodynamic characteristics of the coastal bridges with low elevation are significantly affected by the aerodynamicinterference of coastalhurricane waves.To investigate the aerostatic coefficients of typical streamlined box girder under the influence of solitary waves,a series of parametric wind tunnel tests were conducted,and two-dimensional numerical wind tunnel was established by CFD which was validated by the experiment results.The effect of the horizontal position of the wave crest,vertical bridge clearance,wind attack angle and wave height on the aerostatic coefficient of the box girder were systematic analyzed.And the possible mechanics of aerostatic coefficient change were discussed through flow patterns analysis.The results show that,as the wave crest gradually approaches the girder,the aerostatic coefficient decreases firstly and then increases.The aerostatic coefficient reaches a maximum value when the wave crest locates at 0.5-1 times beam width behind the structure.As the wave crest moves away from the beam,the aerostatic coefficient gradually decreases.It is caused by the change in the direction and pressure of local flow field between wave surface and beam section.The variation amplitude of aerostatic coefficients increases with the decrease of bridge clearance,when vertical bridge clearance is less than twice of the girder width.

关 键 词：极端海浪 箱梁 气动力系数 风洞试验 桥下净空 

分 类 号：U441[建筑科学—桥梁与隧道工程] U446[交通运输工程—道路与铁道工程]