Effects of train nose and blockage ratio on the formation process of the entry compression wave in a high-speed railway tunnel

초록

Entry compression wave is generated in a high-speed railway tunnel due to the train nose ingression at a very high velocity. Due to piston effect there is a sudden rise in pressure inside the tunnel which leads to the formation of the very first or the initial of the successive waves. Ulteriorly, this upsurges into a multitude of wave phenomena due to the reflection and collision of waves on the tunnel wall, thereby, creating a complex sequence of compression waves. Study undertaken here is about the formation process of entry compression wave as a high-speed train enters. A computational investigation on the effect of train nose and blockage ratio has been conducted using dynamic mesh technique. The train is moved using a CG_Motion UDF and the stationary mesh is updated using remeshing and smoothing techniques. The formation process of the entry compression wave has been studied in detail using multiple pressure monitors set on the tunnel wall and the results are comprehended using the pressure plots and contours obtained post the simulations. The post processed contour and vector images gives us a detailed insight on to the flow physics inside the tunnel with the change in above said parameters.