Open AccessTHE OUTFLOW OF AIR FROM POROUS MATERIALS AND THE NOISE REDUCTION THEORY OF POROUS DIFFUSER
Author(s) -
Dayou Ma,
Peizi Li,
Guohao Dai,
Hongyu Wang
Publication year - 1978
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.27.631
Subject(s) - porous medium , porosity , materials science , outflow , diffuser (optics) , noise reduction , noise (video) , reduction (mathematics) , work (physics) , aerodynamics , mechanics , acoustics , optics , physics , composite material , computer science , thermodynamics , meteorology , geometry , mathematics , light source , image (mathematics) , artificial intelligence
Porous diffusers, a distinguished group of silencers, have been developed in the last years, and are used widely in foreign countries. They are preeminent in their small volume, simple structure and high noise reduction. Unfortunately, there are lack of theoretical discussions as yet. In this work, the aerodynamics of flow through porous materials is discused in detail and the authors suggest that the outflow through porous material can be characterized by an effective area and an effective stagnation pressure reduction. Furthermore, the principle of noise reduction of porous diffusers has been studied in some detail, to facilitate the design and the estimation of porous diffusers. Some of the porous diffusers are studied in the light of the present theory.