基于DES的车辆横风气动性能模拟  

Aerodynamic performance of train under cross-wind based on DES

作　　者：苗秀娟[1,2] 高广军[1] 

机构地区：[1]中南大学轨道交通安全教育部重点实验室,湖南长沙410075 [2]长沙理工大学汽车与机械工程学院,湖南长沙410076

出　　处：《中南大学学报（自然科学版）》2012年第7期2855-2860,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51075401,U1134203)

摘　　要：采用分离涡模拟(DES)方法,就横风对车辆侧向气动性能的影响进行数值计算。结果表明:随着风向角的增大,车辆的气动力系数均单调增大,当风向角为90°时达到最大值;在小风向角的情况下,头车的气动力系数最大,尾车最小。对静止车辆来说,车体前端和尾端的流场结构具有较强的对称性,在车辆的头、尾部均会产生脱落涡,且向列车的中部发展,与从风挡处气流分离产生的脱落涡干涉、融合,形成复杂的湍流结构,而中间车则受头、尾车的影响较小,在背风侧产生规则的脱落涡;同时尾涡内流速较低。对运动车辆来说,气流会在头车前端背风侧的上、下部产生2个脱落涡,并沿着车长方向发展,上部的脱落涡和从风挡处产生的脱落涡融合叠加,而下部的脱落涡则不受风挡的影响,同时漩涡内速度较高。Using Detached Eddy Simulation method, the aerodynamic performances of moving high-speed train under cross-wind were numerical simulated. The results show that the aerodynamic coefficients are increased monotonously with the increasing of wind angle, and they reach their maximum values when the wind angle is 90°. The aerodynamic coefficients of front car are the largest while that of tail car are smallest. To the still car, the flow structure behind the front car and the tail car are almost symmetry, shed wake vortexes are produced in these area and progress to the middle of the train, these vortexes intervene and merge with the vortexes from the windshield by flow separation and produce complicated flow structure. While the flow structure behind the middle car is rarely influenced by these vortexes and form regular shed wake vortexes and the velocity and vorticity in the wake vortexes are much small. To the moving car, the separated flow from the leeward of front car form two vortexes and progress along the train. One is on the top of head and the other is under the head. The upper vortex merges and overlaps with the vortexes from the windshield while the lower one is not influenced. The velocity and vorticity in the vortexes are much big.

关 键 词：高速列车 横风 分离涡模拟 气动性能 

分 类 号：U270.11[机械工程—车辆工程]