Analysis of coir fiber acoustical characteristics

被引:184
作者
Fouladi, Mohammad Hosseini [1 ]
Ayub, Md [2 ]
Nor, Mohd Jailani Mohd [2 ]
机构
[1] Taylors Univ Coll, Sch Engn, Subang Jaya 47500, Selangor, Malaysia
[2] Univ Kebangsaan Malaysia, Fac Engn, Dept Mech & Mat Engn, Bangi 43600, Selangor, Malaysia
关键词
Coir fiber; Acoustic absorption coefficient; Porous material; Delany-Bazley model; Biot-Allard model; SOUND-ABSORPTION; ELASTIC WAVES; TRANSMISSION; PROPAGATION; IMPEDANCE;
D O I
10.1016/j.apacoust.2010.09.007
中图分类号
O42 [声学];
学科分类号
070206 ; 082403 ;
摘要
Coir fiber from coconut husk is an important agricultural waste in Malaysia. Acoustic absorption coefficient of the fiber as a porous material is studied in this paper. Two types of fiber are investigated, fresh from wet market and industrial prepared mixed with binder. Moreover two analytical models, namely; Delany-Bazley and Biot-Allard are used for analysis. Experimental measurements in impedance tube are conducted to validate the analytical outcomes. Results show that fresh coir fiber has an average absorption coefficient of 0.8 at f > 1360 Hz and 20 mm thickness. Increasing the thickness is improved the sound absorption in lower frequencies, having the same average at f > 578 Hz and 45 mm thickness. Delany-Bazley technique can be used for both types of fiber while Biot-Allard method is compensated for the industrial prepared fiber considering the binder additive. This form generally shows poor acoustical absorption in low frequencies. Inevitably, fiber has to be mixed with additives in commercial use to enhance its characteristics such as stiffness, unti-fungus and flammability. Hence other approaches such as adding air gap or perforated plate should be used to improve the acoustical properties of industrial treated coir fiber. (C) 2010 Elsevier Ltd. All rights reserved.
引用
收藏
页码:35 / 42
页数:8
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