基于Gamma雨滴谱的降雨对高速列车气动特性影响

Influence of Rainfall on Aerodynamic Characteristics of High Speed Trains based on Gamma Rainfall Spectrum

在风雨条件下列车运行时受到的阻力、升力和倾覆力矩等气动载荷将明显提高,分别采用均匀雨相模型和Gamma谱模型模拟降雨环境,对高速列车的气动特性进行数值模拟.结果表明:在均匀雨相模型条件下,由于横风的加入,降雨强度为100 mm/h时列车受到的阻力比无雨工况时增大了11. 8%,横向力增大了5. 2%;而采用Gamma谱模型在降雨强度为100 mm/h时列车受到的阻力比无雨工况时仅增大了5. 8%,横向力增大了1. 6%.相比Gamma谱模型,列车在均匀雨相模型下运行时的气动力和气动力矩明显偏大;在Gamma谱降雨模型条件下,列车速度变化对列车气动特性影响较大;由于列车头部流场变化较为复杂,头车气动特性变化最大,尾车次之,中间车最小.

Aiming at increasing aerodynamic loads such as drag force,lift force and overturning moment when running in wind and rain conditions,the aerodynamic characteristics of the high-speed train are numerically simulated under a investigated rainfall environment using an uniform rain phase model and a Gamma spectral model.The results show that under the condition of uniform rain phase model with the rainfall intensity of 100mm/h in the crosswind condition,the aerodynamic drag force of the train is increased by11.8%,and the lateral force is increased by 5.2%compared with the no-rain condition.The Gamma spectrum model receives only 5.8%more drag and1.6%more lateral force on the train when rainfall intensity is 100mm/h.Compared with the Gamma spectrum model,the aerodynamic forces and moments of the train under the uniform rain phase model are obviously larger.Under the Gamma spectral rainfall model,the change of train speed has a great influence on the aerodynamic characteristics of the train.The change of aerodynamic characteristics of the train head car is the largest,followed by the train tail,and the train intermediate car is the least.