A study of areca nut leaf sheath fibers as a green sound-absorbing material. (1st December 2020)

• Record Type: Journal Article
• Authors: Raj, Manish; Fatima, Shahab; Tandon, Naresh
• Is Part Of: Applied acoustics. Volume 169(2020)
• Publication Date: 2020-12-01
• Subjects: Sound absorption coefficient -- Natural fiber -- Economical sound absorber -- Sustainable development -- Reduction of synthetic materials; Acoustical engineering -- Periodicals; Periodicals; 620.2
• DOI: 10.1016/j.apacoust.2020.107490
• Languages: English
• ISSNs: 0003-682X

Abstract

Abstract: This study intends to explore the potential of areca nut leaf sheath (ALS) fibers as an efficient sound absorber. The ALS fibers were characterized to investigate their physical properties closely associated with their performance as an efficient sound absorber. ALS fibers were processed into non-woven form and were characterized for their acoustical characteristics. The sound absorption coefficient was measured on samples of different thicknesses as per ASTM E1050. The experimentally measured sound absorption coefficients were compared with the theoretically estimated ones, using the empirical models of Delany-Bazley, Miki, Garai-Pompoli, and Allard. The predicted and experimental results were compared in different frequency zones and for different thicknesses. The accuracy of empirical models was evaluated by analyzing the root mean squared error of sound absorption coefficients. The optimum thickness was identified by analyzing the noise reduction coefficient. A linear and a logarithmic objective function was framed with sound absorption coefficients sampled at 10 Hz, and in 1/12th octave band to further improve the accuracy of the empirical models by inverse acoustical characterization. Inverse acoustical characterization was performed using genetic algorithm on the results of optimum thickness. The inverse acoustical characteristics were used in the most accurate empirical model to estimate the characteristic impedance and complex wavenumber. This characteristic impedance and complex wavenumber were used to study the effect of air–gap behind the ALS sound absorbers. A maximum noise reduction coefficient of 0.78 on a 54 mm thick sample was reported in the presence of a 50 mm air–gap. An effective sound absorber from natural sources was the outcome of the present study.