强横风下列车出隧道时的瞬态气动性能

Aerodynamic performance of train passing out tunnel under cross-wind

运用滑移网格技术,选用工程上常用的k-ε双方程湍流模型,对横风环境下高速列车出隧道口时的瞬态空气动力特性进行数值模拟,得到不同风速、不同车速下列车受到的瞬态风荷载。计算结果表明:车体所受的瞬态风荷载在列车出隧道口的过程中急剧增大,随着列车逐渐脱离隧道而趋于常数;对车辆安全影响较大的侧向力、侧滚力矩中,头车受到的气动力变化幅值最大、尾车最小,中间车居中;列车出隧道过程是车体周围流场压力不断上升的过程;车体水平中心截面上的静压系数曲线在车头处存在1个大2个小共3个峰值;随着列车的运行,其中迎风面的第2峰值逐渐增大超过原最大峰值,而背风侧第2峰值基本保持不变。

Using sliding mesh technology, based on the k-e turbulence model commonly used in engineering, the aerodynamic performance of train passing out the tunnel under cross-wind was simulated and the aerodynamic load was gotten when train has different wind speeds and running speeds. The results show that the aerodynamic forces acting on the train improve sharply and finally go to constant when train runs out of the tunnel. The side force and capsizing moment affecting largely the train running stability change most on the head car, less on the middle car, and least on the middle car. The pressure improves gradually when train runs out of the tunnel. The static pressure coefficient on the center level section of train has one large peak and two small peaks. The small peak pressure coefficient on the inward section of train improves gradually and becomes the largest while the small peak pressure coefficient on the leeward section of train changes very little.