NOVI - Advanced functional solutions for Noise and Vibration reduction of machinery: Deliverable D1.1 Physical mechanisms of absorption and sound insulation
Year of publication
2014
Authors
Uosukainen, Seppo
Abstract
Absorption of acoustic wave is due to viscous and thermal losses and relaxation processes in fluid: - Absorption is emphasized near boundaries, especially in small holes, slits and narrow tubes, - Viscous losses dominate with small free space dimensions: -Perforated / microperforated plates, - Absorbing materials: "Holes" and "slits" described by fluid bulk properties (flow resistivity, porosity, tortuosity, viscous andthermal characteristic lengths). Sound transmission of a wall is due to two parallel transmission paths: - Non-resonant and resonant transmission, - Below coincidence frequency non-resonant transmission dominates except in the resonance region. With double walls above double-wall resonance, sound insulations in dBs are summed with reasonable amount of absorption in cavity if mechanical coupling is insignificant.
Show moreOrganizations and authors
VTT Technical Research Centre of Finland Ltd
Uosukainen Seppo
Publication type
Publication format
Monograph
Audience
Professional
MINEDU's publication type classification code
D4 Published development or research report or study
Publication channel information
Publisher
VTT Technical Research Centre of Finland
Open access
Open access in the publisher’s service
Yes
License of the publisher’s version
Other license
Self-archived
No
Other information
Fields of science
Mechanical engineering
Keywords
[object Object],[object Object],[object Object]
Language
English
International co-publication
No
Co-publication with a company
No
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes