Analytical Method of Noise Contribution Ratio in Railway Vehicle Using Small Speaker and Acoustic Particle Velocity Sensor

Abstract

To apply noise reduction countermeasures effectively in a railway vehicle, it is necessary to clarify the contribution ratio of each noise generation source at each noise evaluation position. The acoustic characteristics of an evaluation position in an enclosed space can be represented as the product of the acoustic particle velocity near the noise source and the acoustic transfer function between the noise source and the evaluation position. Therefore, the authors have developed a new analytical method to estimate the acoustic characteristics of an arbitrary evaluation position in a space, and the noise contribution ratio of noise sources using an acoustic particle velocity sensor and a small loudspeaker. This paper describes the outline of the method and verification results from excitation tests on a stationary test vehicle.