摘要
强脉动环境风加剧高速列车周围流场瞬变特性,进而形成强脉动列车气动载荷,直接危及列车行车安全。当列车在高架桥上运行时,环境风-列车-桥梁耦合条件下的列车气动载荷变化将更为剧烈。因此,采用更加真实的风场边界模拟横风作用下高速列车在桥梁上运行时的气动特性、明确不同风场特征下的列车周围流动结构特征显得尤为重要。基于大涡模拟方法,研究了恒定均匀风场、指数平均风场以及指数脉动风场(基于谐波合成法并采用Kaimal风速谱密度模型生成风速时程数据)特征作用下二维车体在10 m高桥梁上的横风气动特性。研究结果发现:不同风场特征下,车体周围流场结构、气动性能存在较大差异。对比指数平均风场,恒定均匀风场下车体背风侧产生一对更加充分发展的漩涡结构;车体的侧向力系数减少16.4%,升力系数增加59.7%,倾覆力矩系数降低23.6%,不同速度剖面对应的2种时均风场下,列车的气动特性出现了显著差异。当采用更为真实的指数脉动风场剖面时,车体表面压力分布呈现差异性变化,车体的侧向力系数增加9.0%,升力系数减少13.4%,倾覆力矩系数增加9.5%,可见脉动风场对桥梁上高速列车的横风气动性能具有较显著的影响。研究成果可为风环境下桥上高速列车的行车安全和限速指挥系统提供技术支撑。
The strong turbulent environmental wind aggravates the instantaneous characteristics of the flow field around a high-speed train,which then causes strong fluctuating aerodynamic loads of the train and directly poses a risk to the running safety.When the train runs on a viaduct,the aerodynamic load of the train would change more greatly under the coupling condition of the environmental wind,train,and bridge.Therefore,it is particularly important to adopt a more real turbulent wind profile to simulate the aerodynamic characteristics of high-speed trains running on bridges under crosswinds and clarify the flow structures'characteristics around trains under different wind field profiles.Based on the large eddy simulation method,the aerodynamic characteristics of a two-dimensional car body standing on a 10 m high bridge under the constant uniform wind profile,exponential average wind profile and exponential turbulent wind profile(based on the harmonic synthesis method and using Kaimal wind speed spectral density model to generate the time history data of wind speed)were studied.The results show that there are great differences in the flow structure around and the aerodynamic performance of the car body under different wind field profiles.Compared with the exponential average wind profile,a pair of more fully developed vortex structures is produced on the leeward side of the car body under the constant uniform wind profile.The lateral force coefficient of the car body decreases by 16.4%,the lift coefficient increases by 59.7%and the overturning moment coefficient decreases by 23.6%.Thus,there is a significant difference in the aerodynamic characteristics of the trains under the two time-averaged wind fields corresponding to different wind profiles.However,when the exponential turbulent wind profile is adopted,the surface pressure distribution of the car body shows a differential change.The lateral force coefficient of the car body increases by 9.0%,the lift coefficient decreases by 13.4%and the overturning moment coefficient increases by 9.5%,which shows that the turbulent wind profile has a significant impact on the aerodynamic performance of the high-speed train on bridges.The research results of this paper can provide technical support for the operational safety and the speed-limit control system of high-speed trains running on bridges under crosswinds.
作者
张洁
余越
张亮
王璠
许澳
王家斌
ZHANG Jie;YU Yue;ZHANG Liang;WANG Fan;XU Ao;WANG Jiabin(The State Key Laboratory of Heavy-duty and Express High-power Electric Locomotive,Central South University,Changsha 410075,China;Key Laboratory of Traffic Safety on Track of Ministry of Education,School of Traffic&Transportation Engineering,Central South University,Changsha 410075,China;National&Local Joint Engineering Research Center of Safety Technology for Rail Vehicle,Central South University,Changsha 410075,China;CRRC Qingdao Sifang Co.,Ltd.,Qingdao 266111,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2024年第8期3026-3037,共12页
Journal of Railway Science and Engineering
基金
国家重点研发计划课题(2020YFA0710903)
国家自然科学基金联合基金资助项目(U2268217)
中国国家铁路集团有限公司科技研究开发计划(P2021J035)。
关键词
脉动风场
气动性能
横风
高速列车
数值仿真
turbulent wind profile
aerodynamic performance
crosswind
high-speed train
numerical simulation
