The influence of wheel rotation on underbody flow and aerodynamics on high speed train were numerically investigated by using Reynolds averaged Navier-Stokes equations (RANS). Two different conditions including stationary and rotating wheels in CRH3 complex train were calculated, running 380 km/h in the open air. Furthermore, analyses on underbody velocity field, pressure coefficient on bogie sections, wake and leeward vortex structure affected by rotating wheels are performed. The comparison shows that drag coefficient decreases about 1% when wheels rotating. In the rotating condition, the lift forces of train bodies are reduced, especially the bogie sections. The velocity around the tail car's bogies increases 13-20m/s due to the wheel rotation effects, and the vortex cores of wake get closer.

At present, the aerodynamic characteristic of the pantograph has been attached more importance to with the improvement of the high speed train. The excellent aerodynamic characteristic of the pantograph is a significant factor ensuring the current collecting stability between the pantograph and catenary and increasing the using life. The studying methods on it include theoretical computing, numerical simulation and experimentation. Using the commercial soft Fluent, the numerical research of the pantograph aerodynamic characteristic has been made in the different installing place. The calculation precision has been obtained with the suitable meshing, selecting appropriate turbulent model and adopting the right boundary conditions. The simulation results show that the lifting force changes with the fixing place and the dragging force does not transform basically when not considering crosswind. When the crosswind is taken into account, the lifting force changes obviously and the total rolling moment do not change with the installing location. By optimization, the fixing position with the best aerodynamic characteristic is found.