Search for dissertations about: "sound scattering"

Showing result 11 - 15 of 34 swedish dissertations containing the words sound scattering.

  2. 11. Scattering of Elastic Waves by Inhomogeneities in Cylindrical Structures

    Author : Sune Olsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : In the present thesis we extend the null field approach (in the literature also often referred to as "the T matrix method" or "the extended boundary condition method") to some new multiple scattering problems involving infinite cylindrical surfaces and a bounded obstacle. The first case considered is the scattering of acoustic waves by a bounded obstacle outside an infinite cylinder of constant cross section. READ MORE

  4. 12. Acoustic Characterization of Turbochargers and Pipe Terminations

    Author : Heiki Tiikoja; Mats Åbom; Francisco Denia; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustical two-port; turbocharger; transmission loss; sound generation; compressor; turbine; IC-engine; inlet system; exhaust system; flow duct; duct termination; reflection coefficient;

    Abstract : In search for quieter engines there is a need for a better understanding of the acoustic properties of engine intake and exhaust system components. Besides mufflers which have the purpose of reducing pressure pulses originating from the internal combustion (IC) engine, there are many components in a modern car exhaust and intake system, e.g. READ MORE

  5. 13. Room Acoustic Ray-Tracing : Understanding, evaluating and expanding the toolset

    Author : Hanna Autio; Byggnadsmekanik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Room acoustics; acoustic ray tracing; Room acoustic simulation; virtual reality; acoustic scattering;

    Abstract : Room acoustic simulations are an important tool, both for design of spaces with satisfactory acoustics and for use in virtual reality experiences. Auralization of acoustic simulations are becoming more and more important in the context of Virtual and Augmented reality (VR and AR respectively), as the technology is used more and more in healthcare, culture and research. READ MORE

  6. 14. Experimental Determination of Aeracoustic Sources in Low Mach Number Internal Flows

    Author : Andreas Holmberg; Hans Bodén; Lars Enghardt; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aeracoustics; ducts; N-ports; scattering matrix; wave decomposition; source determination; over-determination; flow noise; fluid-acoustic interaction; fluid-structure-acoustic interaction; wave number; T-junction; power balance; grazing-bias flow; Acoustics; Akustik; Vehicle engineering; Farkostteknik;

    Abstract : In this thesis, the in-duct experimental methods for determining aeroacoustic N-ports of in-duct elements are discussed and improved. The scattering matrix determination methods and the related wave decomposition methods are evaluated from measurements in an empty duct carrying a mean flow. READ MORE

  7. 15. Methods and techniques for precise and accurate in-duct aero-acoustic measurements : Application to the area expansion

    Author : Luck Peerlings; Susann Boij; Hans Bodén; Yves Aurégan; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Area-expansion; Scattering matrix; Multi-microphone method; Engineering Mechanics; Teknisk mekanik;

    Abstract : During the design and commissioning of combustion equipment, combustion associated instabilities are commonly encountered. These thermo-acoustic instabilities can cause undesirable noise, vibrations, local thermal and mechanical stresses in the combustor and are prominent in lean combustion. READ MORE