공명형 방음벽 상단장치의 음향성능 평가 방안

Purpose : The purpose of this study is to investigate the acoustic performance evaluation method for resonance type noise reduction device installed on the top of noise barrier. Method: In order to evaluate the acoustic performance of the resonance type noise reduction device installed on the top of noise barrier, the measurement of insertion loss in the semi-anechoic chamber and transmission loss using the impedance tube were conducted. Acoustic mode analysis was also performed to evaluate the resonance frequency of a complicated shaped resonator. By using the two-dimensional boundary element method, the study on the deriving a problem in evaluating the acoustic performance at the rear stage of the resonance type device was conducted and an alternative solution of the problem was suggested, and the acoustic performance in the rear stage of resonance type device was evaluated when a number of resonators were mixed. Result : In order to solve the difficulty in analysis of the acoustic characteristics of resonance type noise reduction device, an effective evaluation method was proposed by using the two-dimensional boundary element method in present work. Also acoustic performance was analyzed at the receiver point of the noise reduction device in which many resonators present simultaneously.