高速列车转向架空气阻力的数值模拟

Numerical simulation of aerodynamic drag for high-speed train bogie

为了研究转向架的空气阻力特性,建立了列车空气动力学模型。基于三维定常可压缩N-S方程和k-ε两方程湍流模型,采用有限体积法对速度为400 km.h-1的高速列车空气动力学性能进行了数值模拟,分析了车底结构对转向架气动力的影响。研究结果表明:转向架区域的流场结构非常复杂,转向架前后都会有漩涡形成;高速列车各转向架所受气动阻力差别很大,无侧风条件下,头车一位端转向架阻力是第4转向架阻力的4倍以上;转向架气动阻力占列车总阻力的20%以上,在侧风作用下占40%以上;不同车体底部形状使转向架阻力最大相差30%以上;适当改进列车底部结构,有利于减少转向架的气动阻力,进而减小列车运行气动阻力。

To study the aerodynamic drag properties of high-speed train bogies,an aerodynamics model of train was built.Based on 3D steady compressible N-S equation and turbulent model of k-ε two equations,the aerodynamics properties of high-speed train running at 400 km·h-1 were numerically simulated by using finite volume method.The influence of train bottom shapes on bogie＇s aerodynamic drag was analyzed.Analysis result shows that the flow field structure of bogie region is very complex.Vortices emerge on both the forward and backward bogies.The aerodynamic drags of bogies are different.Under crosswind-free condition,the aerodynamic drag of the first bogie is more than 4 times of the fourth bogie.The aerodynamic drag of bogie takes up more than 20% of whole train aerodynamic drag,and it is more than 40% under crosswind.The maximum differences of bogie aerodynamic drags are more than 30% due to the different shapes of train bottom.The aerodynamic drags of bogies and whole train reduce due to changing train bottom shape appropriately.2 tabs,10 figs,16 refs.