突变风下车-桥系统三分力系数演化规律的CFD分析  

CFD analysis of the evolution rule of the three-component force coefficient of the vehicle-bridge system under abrupt wind action

作　　者：肖洋 何旭辉[1,2] XIAO Yang;HE Xuhui(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center for High-speed Railway Construction Technology,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程研究中心,湖南长沙410075

出　　处：《铁道科学与工程学报》2025年第2期723-733,共11页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51925808)。

摘　　要：为研究突变风作用下车-桥系统三分力非定常特性问题,以某大桥工程为背景,采用ANSYS Fluent有限元软件建立流线型箱梁和钝体和谐号列车精细化二维数值模型,基于UDF在模型速度入口设置6种突变风工况,分析不同加速度和有无初速度作用下的车-桥系统三分力及其系数演化规律。通过与均匀流对照,研究结果表明:在各突变风工况中,车-桥系统在加速初始和结束时刻会出现阻力跃升和跃跌,这可能与加速度的有无相关,其中流线型箱梁在加速过程中出现阻力超冲现象,超冲系数值最大可达4.1,而钝体列车超冲系数值维持在1.0~1.1,基本无阻力超冲现象。此外,比之无初速工况,有初速会降低阻力超冲系数值。3个气动力系数均出现显著的非定常特性,在加速初段,升力系数C_(L)(t)、阻力系数C_(D)(t)和扭矩系数C_M(t)波动幅度大,加速后段逐步平稳,回到均匀流相应水平。其中无初速的工况车-桥系统三分力系数非定常效应比有初速工况更为明显。在不同加速度的工况之间,非定常效应也存在差异性,对于有初速的突变风工况,在一定范围内,车-桥系统三分力系数非定常效应随着加速度的增大而增大,而对于无初速的工况则随着加速度的增大而减小。可见,有无初速度和加速度的大小是影响突变风下车-桥系统三分力系数非定常特性的因素。研究结果可为突变风作用的气动力非定常特性研究和高速列车行车安全性提供一定参考。The unsteady characteristics of the three-component force coefficients of the vehicle-bridge system were studied under abrupt wind action.Based on the background of a bridge project,a refined two-dimensional numerical model of streamlined box girder and blunt body Harmony train was established by using ANSYS Fluent finite element software.Based on UDF,six abrupt wind conditions were set at the speed entrance of the model to analyze the three-component forces of the vehicle-bridge system and their coefficient evolution rules under different accelerations and with or without initial speed.Compared with the uniform flow,the results show that:in the abrupt wind conditions,the resistance jump and fall occurred at the initial and end of acceleration of the car-bridge system,which may be related to acceleration.The resistance overshoot phenomenon occurs in the streamlined box girder during acceleration,and the overshoot coefficient is up to 4.1,while the overshoot coefficient of the blunt body train is maintained between 1.0~1.1,and there is basically no resistance overshoot phenomenon.In addition,compared with the condition without initial velocity,the value of drag overshoot coefficient would be reduced with initial velocity.The three aerodynamic coefficients all show significant unsteady characteristics.In the initial stage of acceleration,the lift coefficient C_(L)(t),drag coefficient C_(D)(t)and moment coefficient C_(M)(t)fluctuate greatly.After acceleration,the lift coefficient C_(L)(t),drag coefficient C_(D)(t)and moment coefficient C_(M)(t)gradually stabilize and return to the corresponding level of uniform flow.The absolute value of the three-component force of the vehicle-bridge system with the initial speed increases faster,while the unsteady effect of the three-component force coefficient of the vehicle-bridge system without the initial speed is more obvious.There are also variations in the unsteady effects among the conditions with different accelerations.For the abrupt wind conditions with initial velocity

关 键 词：突变风 车-桥系统 超冲系数 三分力系数 非定常效应 CFD 

分 类 号：U441[建筑科学—桥梁与隧道工程]