Influence of the Wheel Rotation on Underbody Flow and Aerodynamic Forces of High Speed Train

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.