Study on Distribution Characteristics of Aerodynamic Drag of a Couple Multiple Units High-Speed Train

Abstract

Based on unsteady N-S equation of three-dimensional and compressible viscous fluid, the transient pressure on the car surface, both the flow structures and aerodynamic loads are analyzed in detail, the contribution value of all regions of a couple multiple units high-speed train for aerodynamic drag coefficient of the CRH2 whole train is studied. The calculation result shows that by contrasting the results of wind tunnel test with numerical simulation respectively using indirect verification method, the change law of aerodynamic effect shows agreeable accordance with the error under 5%. The aerodynamic drag of head surface area of the front and tail car and the bogie region of each car accounts for 75％ of the whole train. The aerodynamic drag coefficient of the later head surface area is twice more than the head surface area in the multiple units region. From the head