철도소음 저감설계를 위한 소음도 시뮬레이션 연구

초록

In this paper, the simulation technology of sound pressures when railway vehicles passe by a microphone or a noise receiver is discussed. Sound powers are predicted using the field measurement with a microphone array system. In order to visualize and determine the sound sources, the measured sound pressure signals are processed by means of the delay-and-sum method and the transfer factors are defined using speaker tests. The sound pressure level at each time instant is the sum of the contribution from all individual sources. Each source contributes to the total sound power level at the receiver position, with an amount defined by sound power of the source, attenuation due to the directivity of the sources, attenuation due to distance between source and receiver. A simulation yields the sound pressure level as a function of time, the A-weighted equivalent sound pressure level and the reduced sound pressures due to noise barriers

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