Modeling pressure variations generated by short train passing in open air

Abstract The pressure variation generated when a high-speed train passes in open air affects structures on the ground and causes environmental problems. It was assumed in past studies that the effect of the train nose passage is independent of the tail passage for long trains (with 16 cars). In these studies, only the effect of the nose passage was analyzed with a point source model. However, as the superposition of the effect of the nose and tail is not negligible for short trains (consisting of less than 10 cars), the entire pressure variation should be analyzed. For this purpose, the positions of sources representing the nose and tail need to be considered. In this study, a model experiment and theoretical analysis on the pressure variation when a short train passes in an open air environment were performed. The experimental results show that the negative peak amplitude is greater than the positive peak amplitude for observation points located over 1/10 of the train length away from the train, because of superposition. The distance between the two zero-pressure points is different from the train length. The effects of nose and tail configurations are considered in the proposed line source model and point source model based on the typical potential theory; the prediction results of the models showed good agreement in the waveforms and peak values of the pressure variation compared with those in model experiments. Therefore, we herein demonstrate that the line source model is valid, and the point source model is applicable to short trains when considering the positions of the point sources.