Geometrical and Dimensional Optimization of Sound Absorbing Porous Copper with Cavity

Publication date: 5 October 2017
Source:Materials & Design, Volume 131
Author(s): Xiaocui Yang, Kang Peng, Xinmin Shen, Xiaonan Zhang, Panfeng Bai, Pengjin Xu
Optimization of sound absorbing coefficient of porous copper under a limited dimension is focus of research in the fields of acoustics and mechanics. Through measuring the sound absorbing coefficient based on the standing wave method, 5 groups of experiments are conducted to investigate the sound absorbing property of the porous copper with cavity under a limited dimension of 30mm. There are two options can meet the requirement that the sound absorbing coefficients are larger than 70% in 2000-5000Hz. First is the pure porous copper with thickness of 30mm, and the other is the combination of porous copper with thickness of 25mm and cavity with thickness of 5mm. Based on the modified Johnson-Allard model with correction factor, it can be obtained that theoretical optimal thickness of the pure porous copper is 28.8mm, and the theoretical optimal combination of porous copper and cavity are 22.7mm and 7.3mm. Experimental validations indicate that the two optimal options of the two modes both can meet the sound absorbing requirement. The results will promote the application of porous copper and improve the sound absorbing theory of porous material.

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