Experimental investigation of sound absorption in a composite absorber  

作　　者：Nansha Gao Hong Hou 

机构地区：[1]Key Laboratory of Ocean Acoustic and Sensing,School of Marine Science and Technology,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Theoretical & Applied Mechanics Letters》2021年第1期58-62,共5页力学快报（英文版）

基　　金：by Aeronautical Science Foundation of China(Grant 20181553015);Foundation of Shaanxi Educational Committee(Grant 2018BSHYDZZ03);the National Natural Science Foundation of China(Grant 11704314);China Postdoctoral Sci-ence Foundation(Grant 2018M631194).

摘　　要：A composite absorber made of a polyurethane sponge and multi-layer micro-perforated plates is pre-sented in this study.Results from an acoustic impedance tube test show that the polyurethane sponge can exhibits higher low-frequency sound absorption in front of the micro-perforated plate,while sound absorption at medium and high-frequencies remains low.The physical mechanism behind this is that the micro-perforated plate increases the denpth cavity.If the polyurethane sponge is placed behind the micro-perforated plate,the amplitude of the original absorption peak will remain constant,but the ab-sorption peaks will shift to lower frequencies.The reason for this phenomenon is that porous materials with low flow resistance can be approximately equivalent to fluid,which not only does not affect the res-onance absorption coefficient of micro-perforated plate,but also makes the peaks move to low frequency.This study has the potential applications in the sound absorption design of composite structure.

关 键 词：Composite absorber Multi-layer micro-perforated plate Porous material Sub-wavelength sound absorption 

分 类 号：TB535[理学—物理]