Dynamic flow resistivity and sound absorption of compressed fibrous porous materials: Experimental and theoretical

2020 ◽  
Vol 32 (12) ◽  
pp. 127103
Author(s):  
Jingfeng Ning ◽  
Yueming Li
2014 ◽  
Vol 57 (11) ◽  
pp. 2096-2105 ◽  
Author(s):  
Han Meng ◽  
QingBo Ao ◽  
HuiPing Tang ◽  
FengXian Xin ◽  
TianJian Lu

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1091 ◽  
Author(s):  
Dengke Li ◽  
Daoqing Chang ◽  
Bilong Liu

The diffuse sound absorption was investigated theoretically and experimentally for a periodically arranged sound absorber composed of perforated plates with extended tubes (PPETs) and porous materials. The calculation formulae related to the boundary condition are derived for the periodic absorbers, and then the equations are solved numerically. The influences of the incidence and azimuthal angle, and the period of absorber arrangement are investigated on the sound absorption. The sound-absorption coefficients are tested in a standard reverberation room for a periodic absorber composed of units of three parallel-arranged PPETs and porous material. The measured 1/3-octave band sound-absorption coefficients agree well with the theoretical prediction. Both theoretical and measured results suggest that the periodic PPET absorbers have good sound-absorption performance in the low- to mid-frequency range in diffuse field.


2016 ◽  
Author(s):  
Lianhui Wang ◽  
Shuming Chen ◽  
Dengfeng Wang ◽  
Yang Jiang ◽  
Jing Chen

2018 ◽  
Vol 10 ◽  
pp. 25-35 ◽  
Author(s):  
Leitao Cao ◽  
Qiuxia Fu ◽  
Yang Si ◽  
Bin Ding ◽  
Jianyong Yu

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4605
Author(s):  
Théo Cavalieri ◽  
Jean Boulvert ◽  
Gwénaël Gabard ◽  
Vicent Romero-García ◽  
Marie Escouflaire ◽  
...  

The design of graded and anisotropic materials has been of significant interest, especially for sound absorption purposes. Together with the rise of additive manufacturing techniques, new possibilities are emerging from engineered porous micro-structures. In this work, we present a theoretical and numerical study of graded and anisotropic porous materials, for optimal broadband and angular absorption. Through a parametric study, the effective acoustic and geometric parameters of homogenized anisotropic unit cells constitute a database in which the optimal anisotropic and graded material will be searched for. We develop an optimization technique based on the simplex method that is relying on this database. The concepts of average absorption and diffuse field absorption coefficients are introduced and used to maximize angular acoustic absorption. Numerical results present the optimized absorption of the designed anisotropic and graded porous materials for different acoustic targets. The designed materials have anisotropic and graded effective properties, which enhance its sound absorption capabilities. While the anisotropy largely enhances the diffuse field absorbing when optimized at a single frequency, graded properties appear to be crucial for optimal broadband diffuse field absorption.


2005 ◽  
Vol 66 (6) ◽  
pp. 625-651 ◽  
Author(s):  
F.C. Sgard ◽  
X. Olny ◽  
N. Atalla ◽  
F. Castel

Sign in / Sign up

Export Citation Format

Share Document