Eventos Anais de eventos
CONEM 2018
X Congresso Nacional de Engenharia Mecânica
Avaliação da porosidade de materiais absorventes utilizados em filtros acústicos dissipativos
Submission Author:
Ana Carolina Mendonça Mansur , SC
Co-Authors:
Ana Carolina Mendonça Mansur, Vinicius Antonio Grossl, Key Fonseca de Lima
Presenter: Ana Carolina Mendonça Mansur
doi://10.26678/ABCM.CONEM2018.CON18-0527
Abstract
The Human is continually exposed to noise emitted by automotive vehicles. In order to attenuate these undesirable sounds, in many situations low frequency acoustic filters are used; since automotive noise has significant energy up to approximately 1,000 Hz. The absorbent materials are generally fibrous and porous. In addition, they have the property of being excellent acoustic sinks for a large frequency band. The efficiency of a fibrous absorbent material is made by two properties: the porosity () and the resistivity of the flow (R). The porosity () is the fraction of the air volume of the absorbent material, which is calculated by the ratio of the free pore volume to the total volume of the absorbent material. The present work aims to evaluate experimentally and to correlate the porosity with the flow resistivity from the stand built in the Dynamics Laboratory of PUCPR. Samples of 5, 10, 20, and 22 mm of thickness were evaluated, both with 100 mm of diameter; being foams with densities of 45.5 and 26.6 kg / m³, coconut fibers and sisal.
Keywords
Porosity, Acoustics
