Wind tunnel tests on the control of aeroacoustic noise from high speed train

Abstract

In this study, we propose techniques for reducing the noise from gaps between Shinkansen cars based on the results of noise source localization in wind tunnel testing. In order to obtain the accurate noise source distributions, the microphone array is installed near the train model. The influence of the shear layer around the main flow on the directivity of the microphone array is clarified so that the microphone array should be set in the shear layer rather than the outside of the flow. Analysis of the noise source localization reveals the principal noise sources around the gap, which suggests efficient approaches to the noise reduction. Firstly, we found that the noise level of the gap section with rounded edge can be effectively reduced by approximately 7 dB compared with that of the case with current condition. We also confirmed qualitatively the effect of noise reduction techniques for the gap section by the field test. © 2008 Springer-Verlag Berlin Heidelberg.