Acoustic modelling of micro-pressure waves emitted from high-speed railway tunnels with vented tunnel hoods

摘要

A train generates a compression wave, when it enters a tunnel. When the compression wave arrives at the tunnel exit, a micro-pressure wave (MPW) is emitted outwards. The MPW assessment method should be considered, when predicting the MPW emission. For instance, although the German assessment uses the Japanese one as a reference, it differs from the Japanese assessment. In this study, we apply analytical MPW emission models and the CFD technique to a tunnel with an exit vented hood and validate for both the Japanese and German assessments. It is demonstrated that the low frequency components of the MPWs and the effect of the windows installed at the exit hood are important for the Japanese assessment; on the other hand, the low frequency approximation is not adequate for the German assessment.