Fractal Model for Acoustic Absorbing of Porous Fibrous Metal Materials

Autor: Weihua Chen, Tianning Chen, Xiaopeng Wang, Jiuhui Wu, Suobin Li
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Shock and Vibration, Vol 2016 (2016)
Druh dokumentu: article
ISSN: 1070-9622
1875-9203
DOI: 10.1155/2016/2890857
Popis: To investigate the changing rules between sound absorbing performance and geometrical parameters of porous fibrous metal materials (PFMMs), this paper presents a fractal acoustic model by incorporating the static flow resistivity based on Biot-Allard model. Static flow resistivity is essential for an accurate assessment of the acoustic performance of the PFMM. However, it is quite difficult to evaluate the static flow resistivity from the microstructure of the PFMM because of a large number of disordered pores. In order to overcome this difficulty, we firstly established a static flow resistivity formula for the PFMM based on fractal theory. Secondly, a fractal acoustic model was derived on the basis of the static flow resistivity formula. The sound absorption coefficients calculated by the presented acoustic model were validated by the values of Biot-Allard model and experimental data. Finally, the variation of the surface acoustic impedance, the complex wave number, and the sound absorption coefficient with the fractal dimensions were discussed. The research results can reveal the relationship between sound absorption and geometrical parameters and provide a basis for improving the sound absorption capability of the PFMMs.
Databáze: Directory of Open Access Journals