Effect of Train Nose on Formation of Entry Compression Wave in a High-speed Railway Tunnel

초록

High-Speed train nose design plays a big role in deciding the running speed of the train. Since, train running into a tunnel acts as a piston to push the air ahead of it to coalesce into a compression wave. This compression wave thereafter propagates further at the local speed of sound exiting as a micro-pressure wave. A CFD analysis has been undertaken here to understand the effect of train nose variation on the formation process of the compression wave at the entrance. Three different train nose lengths have been tried and the cross-sectional area has been varied. Later, an optimal constant area variation train nose has been chosen to compare with the initially tried train nose cases. The formation length of the entry compression wave is plotted using pressure monitors set throughout the tunnel wall. The pressure contours presented here show the detailed flow physics to comprehend and understand the obtained CFD results better