Search for dissertations about: "sound scattering"

Showing result 1 - 5 of 25 swedish dissertations containing the words sound scattering.

  1. 1. Sound propagation around off-shore wind turbines

    University dissertation from Stockholm : Byggvetenskap

    Author : Lisa Johansson; KTH.; [2003]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind turbine noise; off-shore wind powe; long-rage sound propagation; parabolic equation; scattering; water waves; TECHNOLOGY Civil engineering and architecture Building engineering; TEKNIKVETENSKAP Samhällsbyggnadsteknik och arkitektur Byggnadsteknik;

    Abstract : Low-frequency, long-range sound propagation over a seasurface has been calculated using a wide-angel Cranck-NicholsonParabolic Equation method. The model is developed toinvestigate noise from off-shore wind turbines. Thecalculations are made using normal meteorological conditions ofthe Baltic Sea. READ MORE

  2. 2. Sound propagation from sustainable ground vehicles from aeroacoustic sources to urban noise

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Nicolas Pignier; KTH.; KTH.; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound propagation; sound generation; ground vehicle; aeroacoustics; aerodynamics; Kirchhoff approximation; detached eddy simulation; Ffowcs Williams and Hawkings; ljudutberdning; ljudalstring; markfordon; aeroakustik; aerodynamik; Kirchhoff approximation; detached eddy simulation; Ffowcs Williams and Hawkings; Farkostteknik; Vehicle and Maritime Engineering; Teknisk mekanik; Engineering Mechanics;

    Abstract : Transportation is the main source of environmental noise in Europe, with an estimated 125 million people affected by excessive noise levels from road traffic, causing a burden of noise related diseases and having a substantial economic impact on society. In order to reduce exposure to high levels of traffic noise, two approaches are the topic of extensive research: preventing sound from propagating from roads and railways using for example noise barriers, and reducing the sources of noise themselves. READ MORE

  3. 3. Acoustic scattering in ducts and influence of flow coupling

    University dissertation from Stockholm : KTH

    Author : Susann Boij; KTH.; [2003]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound; vortex sheet; flow separation; end correction; Strouhal number; non-orthogonal modes; energy balance; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : The subject of this thesis is the acoustic properties offlow duct area expansions and the influence of flow-acousticcoupling at sharp edges. For low Mach number flow, significantinteraction between the sound field and the flow field canoccur at such points of flow separation. READ MORE

  4. 4. Flow Duct Acoustics An LES Approach

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Emma Alenius; KTH.; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aero-acoustics; duct-acoustics; sound generation; acoustic scattering; acoustic-flow interaction; LES; IC-engines; orifice plate; confined jet;

    Abstract : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. Simulations are an important tool for enhanced understanding; they give insight into the flow-acoustic interaction in components where it is difficult to perform measurements. READ MORE

  5. 5. New Methods for Reducing Ground-Borne Noise in Buildings above Railway Tunnels

    University dissertation from Stockholm : Byggvetenskap

    Author : Osama A. B. Hassan; KTH.; [2003]
    Keywords : Ground-borne noise; railway noise; in-plane waves; wave-guides; scattering; propagation constant; input mobility; elastic stratum; dual integral equations;

    Abstract : The rapid expansion of major cities in the west Europeancountries has accentuated the need to exploit every potentialsite for new establishments, e.g. areas over train tunnels andnear railway tracks in general. READ MORE