Prediction and alleviation of a booming noise created by a high-speed train moving into a tunnel

A high-speed train moving into a tunnel creates a compression wave which causes a booming noise at the tunnel exit. In the present paper, this compression wave is studied both numerically and analytically with the emphasis of prediction and alleviation of the booming noise. Three dimensional practical flow fields where a train moves into a tunnel is solved numerically with the zonal method. The computational results are validated with the field measurement data and the detail of the flow field is investigated. In the analytical approach, the flow field is modeled as a stream tube and the key parameter which dominates the compression wave is derived. Based on the result, new method for prediction and alleviation of the booming noise is proposed.