Tunnel entry flow analysis of high speed train with wedge shaped nose

The three-dimensional unsteady compressible Navier-Stokes equation solver with sliding multi-block method has been applied to analyze the flow field around the high speed train which is entering into a tunnel. The numerical scheme of AF+ADI was used to efficiently solve Navier-Stokes equations in the curvilinear coordinate system. In order to handle the relative motion of the moving train and the stationary tunnel, the sliding multi-block technique was implemented. From the present study, the generation of compression wave was observed ahead of the train in the form of plane wave and the high pressure in the gap between the train and the tunnel was also found due to the blockage effects. The variation of pressure of tunnel surface and velocity profile of the train are identified as the train enters into a tunnel. The dramatic changes in aerodynamic forces are also discussed.