Sökning: "sound transmission loss"
Visar resultat 16 - 20 av 25 avhandlingar innehållade orden sound transmission loss.
16. Design of soundproof panels via metamaterial concept
Sammanfattning : The goal of the work is to find a way to improve the sound insulation properties of different types of panels in order to meet different requirements. Inspired by the nontrivial behavior of the locally resonant acoustic metamaterials, this concept is introduced into the design of structures in order to explore the potential ways to improve the sound insulation behavior in the relevant specific frequency regions. LÄS MER
17. Structure-acoustic analysis; finite element modelling and reduction methods
Sammanfattning : This thesis investigates structure-acoustic systems by use of finite element analysis. The systems studied here are limited to those that consist of an enclosed acoustic fluid cavity, which is coupled to a flexible structure and/or a porous sound absorbing material domain. LÄS MER
18. Hearing by Bone Conduction. Physical and Physiological Aspects
Sammanfattning : Bone conduction as a phenomenon, physically and physiologically, is of vital importance in both the diagnosis of a hearing impairment and the development of bone conduction hearing aids. Understanding hearing by bone conduction is difficult, involving sound transmission by wave motion in a complex geometrical structure of layered bone covered with soft tissue and cartilage, finally received by the highly delicate cochlea. LÄS MER
19. An experimental and numerical study of an automotive cooling module
Sammanfattning : Heavy vehicles are major emitters of noise. Especially at idle or low vehicle speeds a large portion of the noise emanates from the fan that forces the flow through the cooling module. The aim of this work is to investigate and reveal aerodynamic and acoustic installation effects linked to the cooling package. LÄS MER
20. Wave Modelling Techniques for Medium and High Frequency Vibroacoustic Analysis Including Porous Materials
Sammanfattning : Numerical methods based on wave modelling are explored for the vibroacoustic analysis of wave propagation, sound transmission and interior noise in vehicles and buildings at medium and high frequencies. The presence of sound absorbing porous materials in practical engineering structures is also considered. LÄS MER