Sökning: "Vehicle Acoustics"

Visar resultat 1 - 5 av 156 avhandlingar innehållade orden Vehicle Acoustics.

  1. 1. The influence of tyre air cavities on vehicle acoustics

    Författare :Èric Torra i Fernàndez; Anders Nilsson; Wim Desmet; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; tyre-road noise; tyre; air cavity resonances; interior noise; aluminium foams; Acoustics; Akustik;

    Sammanfattning : The tonal character of the low frequency internal noise in cars is often due to energy transmission through the tyre at the first few eigenfrequencies of the air cavity of the tyre. The first acoustic mode in the air cavity of a typical stationary car tyre is approximately 224 Hz. LÄS MER

  3. 2. Aerodynamics of vehicle platooning

    Författare :Johannes Törnell; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; close proximity; drag; platooning; cab over engine; aerodynamics; yaw; wake; side wind; truck; inter-vehicle distance; lateral offset;

    Sammanfattning : Many factors are pushing automotive manufacturers to increase the efficiency of their fleets; some of these are legislative (requiring reduced greenhouse gas emissions) as well as ensuring sufficient range and power consumption in electric vehicles. An important part of improving the energy efficiency of road vehicles is reducing their aerodynamic drag. LÄS MER

  4. 3. On Noise Generation and Dynamic Transmission Error of Gears

    Författare :Mats Henriksson; Leping Feng; Reader Andy Moorhouse; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle engineering; Farkostteknik; Acoustics; Akustik;

    Sammanfattning : Noise from heavy trucks is an important environmental issue. Several sources contribute to the total noise level of a vehicle, such as the engine, gearbox, tires, etc. The tonal noise from the gearbox can be very disturbing for the driver, even if the noise level from the gearbox is lower than the total noise level. LÄS MER

  5. 4. Experimental Determination of Aeracoustic Sources in Low Mach Number Internal Flows

    Författare :Andreas Holmberg; Hans Bodén; Lars Enghardt; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  7. 5. Rotating Structure Modeling and Damping Measurements

    Författare :Jia Sun; Leif Kari; Damian Vogt; Ulf Orrenius; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik; Vehicle engineering; Farkostteknik; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Sammanfattning : The structural damping is of importance to suppress the vibration amplitude of compressor blades rotating at high angular velocity under a high cycle impact. To avoid the appearance of the high cycle fatigue (HCF), damping materials may be applied to the compressor blades. LÄS MER