Search for dissertations about: "sound scattering"

Showing result 6 - 10 of 34 swedish dissertations containing the words sound scattering.

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

    Author : Osama A. B. Hassan; KTH; []
    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

  4. 7. Experimental Studies of Neutron Emission Induced by Heavy-Ion Scattering

    Author : Pawel Nadel-Turonski; Leif Nilsson; Adriaan van den Berg; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nuclear physics; neutron; inelastic scattering; heavy ions; position sensitive silicon detectors; storage ring; cluster-jet target; differential cross section; Kärnfysik; Nuclear physics; Kärnfysik;

    Abstract : A beam of 250A MeV 17O ions was scattered from argon and xenon targets. The large excess of fast neutrons compared with statistical model calculations that was observed earlier for xenon, was confirmed and found for argon as well. READ MORE

  5. 8. A Wave Expansion Method for Aeroacoustic Propagation

    Author : Johan Hammar; Gunilla Efraimsson; Ciarán J. O'Reilly; Wim De Roeck; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sound propagation; Sound generation; Aeroacoustics; Aerodynamics; Computational fluid dynamics; Computational aeroacoustics; Numerical methods; Lighthill; Curle; Ffowcs Williams and Hawkings; Frequency-domain propagation; Wave expansion method.; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : Although it is possible to directly solve an entire flow-acoustics problem in one computation, this approach remains prohibitively large in terms of the computational resource required for most practical applications. Aeroacoustic problems are therefore usually split into two parts; one consisting of the source computation and one of the source propagation. READ MORE

  6. 9. Predicting the sound field from aeroacoustic sources on moving vehicles : Towards an improved urban environment

    Author : Nicolas Pignier; Ciarán O'Reilly; Susann Boij; Michael Carley; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pass-by simulations; aeroacoustic sources; urban sound propagation; direct numerical beamforming; linear programming deconvolution; Kirchhoff approximation; moving sources; detached-eddy simulation; Ffowcs Williams-Hawkings; vehicle design; förbifartssimuleringar; aeroakustiska källor; urban ljudutbredning; direkt numerisk lobformning; avfaltning med hjälp av linjärprogrammering; Kirchhoffs approximation; rörliga källor; detached-eddy simulation; Ffowcs Williams-Hawkings; fordonsdesign; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : In a society where environmental noise is becoming a major health and economical concern, sound emissions are an increasingly critical design factor for vehicle manufacturers. With about a quarter of the European population living close to roads with heavy traffic, traffic noise in urban landscapes has to be addressed first. READ MORE

  7. 10. Road traffic noise reduction by multiple scattering and absorption mechanisms

    Author : Bart van der Aa; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Outdoor sound propagation; Sonic crystals; Road traffic noise; FDTD; Noise barriers; MST; Porous materials; 2.5D MST; Graded index sonic crystals;

    Abstract : Millions of people in Europe, and even more on a global scale, are affected by environ- mental noise. Traffic related noise is estimated to cause a yearly loss of approximately one million healthy life years in Western Europe, which is mostly related to road traffic noise. READ MORE