Numerical simulation of aerodynamic drag for high-speed train bogie

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-e 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.