Title of article :
ON THE ACOUSTIC ABSORPTION OF POROUS MATERIALS WITH DIFFERENT SURFACE SHAPES AND PERFORATED PLATES
Author/Authors :
CHEN، نويسنده , , WEN-HWA and LEE، نويسنده , , FAN-CHING and CHIANG، نويسنده , , DAR-MING، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2000
Pages :
19
From page :
337
To page :
355
Abstract :
In architectural acoustic design, perforated plates are often used to protect porous materials from erosion. Although porous materials are usually applied to passive noise control, the effects of their surface shapes are seldom studied. To study the acoustic absorption of porous materials with different surface shapes and perforated plates, an efficient finite element procedure, which is derived by the Galerkin residual method and Helmholtz wave propagation equation, is used in this work. The two-microphone transfer function method and the modified Ingard and Dear impedance tube testing system are employed to measure the parameters deemed necessary for the finite element analysis, such as complex wave propagation constant, characteristic impedance and flow resistivity. For verifying the finite element results, the two-microphone transfer function method is also applied to measure the absorption coefficients of the discussed acoustic absorbers. Four surface shapes of commercially available porous materials, i.e., triangle, semicircle, convex rectangle and plate shapes, are chosen for analysis. The porosity of perforated plates is then evaluated. Finally, the distinct effect of the flow resistivity of porous materials on the acoustic absorption is demonstrated.
Journal title :
Journal of Sound and Vibration
Serial Year :
2000
Journal title :
Journal of Sound and Vibration
Record number :
1390521
Link To Document :
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