Transient Aerodynamic Numerical of Trains Crossing in Tunnel

The Dynamic mesh which offered by commercial computational fluid dynamics(CFD) software was adopted to realize transient aerodynamic characteristics numerical simulation during the crossing process. the Navier-Stokes (N-S) equations and standard turbulence model were applied to set up the model. The train transient aerodynamic characteristic during the crossing process has been research. The simulation results show that carrying on the transient state aerodynamics value simulation to the train is feasible, the flow field around train has a remarkable change in the process of crossing, the law of the piston wind and pressure change sharply like sinusoidal functions. It is of significant importance for further studying the structure of train, shorten its development and guiding significance for practical application.