Sökning: "Porous absorbers"
Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Porous absorbers.
Sammanfattning : Working with textiles in an acoustic context gives enormous possibilities to combine the acoustic function of materials with the visual function (aesthetics). Depending on the material choice and the production techniques, textiles may for instance be flexible, stiff, airtight, have high density or high porosity. LÄS MER
Sammanfattning : Environmental noise has for decades been a well known problem, especially in urban areas. As noise requirements for vehicles are sharpened, noise reducing concepts are needed in early design stages requiring accurate simulations to support the design. LÄS MER
Sammanfattning : The sound absorption characteristics of resonant absorbers, implemented as perforated suspended inner ceilings attached with thin porous layers, are investigated. Several existing theories model the principal absorption mechanisms, but the interaction with the outer sound field influences the absorption in ways that can be modelled with new approaches. LÄS MER
Sammanfattning : The objective of this doctoral thesis is to study three different innovative noise control techniques in ducts namely: acoustic metamaterials, porous absorbers and microperforates. There has been a lot of research done on all these three topics in the context of duct acoustics. LÄS MER
Sammanfattning : For quite some time, the strive for more efficient acoustic absorbers keepsincreasing, driven by a number of psycho-physiological studies on health re-lated dangers of noise exposure. As the global wealth increases and with itthe global expectation of quieter living and working environments, manifestedin both politics and research, an important market for sound absorbing andnoise control systems develops in all industrialised countries. LÄS MER