铁道科学与工程学报2025，Vol.22Issue(2)：723-733,11.DOI:10.19713/j.cnki.43-1423/u.T20240580
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
摘要
Abstract
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 CL(t),drag coefficient CD(t)and moment coefficient CM(t)fluctuate greatly.After acceleration,the lift coefficient CL(t),drag coefficient CD(t)and moment coefficient CM(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,the unsteady effects of the three-component force coefficient of the vehicle-bridge system increase with the increase of acceleration within a certain range;however,for the conditions without initial velocity,the unsteady effects decrease with the increase of acceleration.It can be seen that the initial velocity and acceleration were the factors that affect the unsteady characteristics of the three-component force coefficient of the vehicle-bridge system under abrupt wind.The research results can provide some references for the study of unsteady aerodynamic characteristics under abrupt wind action and the running safety of high-speed trains.关键词
突变风/车-桥系统/超冲系数/三分力系数/非定常效应/CFDKey words
abrupt wind/vehicle-bridge system/overshoot coefficient/three-component force coefficient/unsteady effect/computational fluid dynamics分类
交通工程引用本文复制引用
肖洋,何旭辉..突变风下车-桥系统三分力系数演化规律的CFD分析[J].铁道科学与工程学报,2025,22(2):723-733,11.基金项目
国家自然科学基金资助项目(51925808) （51925808）
