| Summary: | 碩士 === 國立臺灣海洋大學 === 系統工程暨造船學系 === 107 === This thesis first introduces the difference between the micro-perforated panel and the perforated panel. And the composition and Sound absorption performance of the micro-perforated panel resonant sound absorption structure. And discuss the internal structure of the duct. The theory of acoustic impedance of modern micro-perforated panel is proposed by Dr. Ma Dazhao.
Wind tube silencer box insertion loss experiment is time-consuming and laborious. To this end, this thesis designs a method to evaluate the insertion loss of micro-perforated silencer box. This method can easily measure the vertical incident sound absorption rate of the micro-perforated panel resonant sound absorption structure by using the impedance tube experiment. And using this sound absorption ratio with the acoustic finite element method to find the acoustic impedance of the micro-perforated panel on the resonant sound absorbing structure. Using this acoustic impedance to simulate the simulated insertion loss value of the micro- perforated silencer box. The error between the simulated insertion loss value and the actual experimental insertion loss value is within the tolerance of 3 dB. This method does not have any structural limitations on micro-perforated panel. Such hole, hole type, panel thickness, etc.
At the end of the thesis, it is also compared with the theoretical formula of Ma Dazhao's micro-perforated panel. In this thesis, the acoustic impedance values of micro-perforated panel are calculated by impedance tube experiment and acoustic finite element method. As well as the acoustic impedance value of the micro-perforated panel are calculated by the theoretical formula. Simulated insertion loss in acoustic simulation of micro-perforated silencer box. Obviously, the error of the insertion loss value simulated by the thesis method is small. Explain the feasibility of the method proposed in this thesis.
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