Aerodynamic noise characteristics of a specific position of a passing high-speed train by the beampower spectrum

초록

The purpose of this paper is to derive aerodynamic noise characteristics of a specific position of a high-speed train. As the high-speed train speed increases, aerodynamic noise radiation from the train increases exponentially. In this sense, it is important to understand aerodynamic noise characteristics of high-speed trains. However, the experimental characterization of the acoustic sources on high-speed vehicles is a difficult task due to turbulence from the fluctuating part of the velocity field. Therefore, the beamforming method was used to characterize aerodynamic noise of high-speed trains in this paper. First, pass-by noise of a Korean high-speed train (KTX-1) was measured by a microphone array system. This noise maps suggested that the majority of the aerodynamic noise produced came from the bogie area, the pantograph and its cover, and inter-coach gaps. Then, beampower outputs of specific positions in high-speed trains were obtained by the delay and sum method and the beampower spectrum of them were deduced from the frequency conversion. From this study, aerodynamic noise characteristics from the major sources of high-speed trains were drawn.