Sökning: "Marcus Wallenberg"

Visar resultat 11 - 15 av 57 avhandlingar innehållade orden Marcus Wallenberg.

  1. 11. Reduction of Audible Noise of a Traction Motor at PWM Operation

    Författare :Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic noise; pulse width modulation PWM ; switching frequency; traction motor; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : A dominating source for the radiated acoustic noise from a train at low speeds is the traction motor. This noise originates from electromagnetic forces acting on the structure resulting in vibrations on the surface and thus radiated noise. It is often perceived as annoying due to its tonal nature. LÄS MER

  3. 12. Statistical energy analysis and variational principles for the prediction of sound transmission in multilayered structures

    Författare :Mathias Barbagallo; Svante Finnveden; Jean-Louis Guyader; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; statistical energy analysis; porous materials; biot theory; variational principles; hamilton principle; double walls; multilayered structures; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Sammanfattning : Multilayered structures have many application in industry and society: they have peculiar properties and serve a variety of purposes, like structural support, thermal insulation, vibrational and acoustic isolation. This thesis concerns the prediction of sound transmission in multilayered structures. LÄS MER

  4. 13. Magneto-sensitive rubber in the audible frequency range

    Författare :Peter Blom; Leif Kari; Luigi Bregant; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magneto-sensitivity; Rubber; Audible frequency range; Amplitude dependence; Vibration isolator; Fletcher-Gent effect; Stiffness; Acoustics; Akustik;

    Sammanfattning : The dynamic behaviour in the audible frequency range of magneto-sensitive (MS) rubber is the focus of this thesis consisting of five papers A-E. Paper A presents results drawn from experiments on samples subjected to different constant shear strains over varying frequencies and magnetic fields. LÄS MER

  5. 14. Wind Turbine Noise and Natural Sounds : Masking, Propagation and Modeling

    Författare :Karl Bolin; Mats Åbom; Jens Forssén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind turbine noise; models of natural sound sources; masking; Acoustics; Akustik;

    Sammanfattning : Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. LÄS MER

  7. 15. Modelling and simulation of electromagnetic audible noise generated by traction motors

    Författare :Fredrik Botling; Ines Lopez Arteaga; Siv Leth; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vibro-acoustics; Electromagnetic noise; traction motor; modal analysis; multi-physics; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : An annoying tonal noise is produced by modern electrical trains duringacceleration and deceleration. This noise is caused by electromagneticforces generating structural vibrations, especially from the traction motors. LÄS MER