Search for dissertations about: "Avraham Hirschberg"

Found 2 swedish dissertations containing the words Avraham Hirschberg.

  2. 1. Assessing precision and accuracy in acoustic scattering matrix measurements

    Author : Luck Peerlings; Hans Bodén; Susann Boij; Avraham Hirschberg; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aero-acoustics; sudden area expansion; in-duct acoustics; acoustic scattering matrix; impedance tube; uncertainty analysis; systematic errors; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : Acoustic scattering matrices are used to characterize the influence of inline duct elements on the acoustic wave propagation in wave guides.When measuring the properties of these matrices, errors are always present in the results and need to be characterized to make valid statements on the correspondence between model predictions and measurements. READ MORE

  4. 2. Modeling of sound-turbulence interaction in low-Mach-number duct flows

    Author : Chenyang Weng; Mats Åbom; Susann Boij; Avraham Hirschberg; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Abstract : When sound waves propagate in a duct in the presence of turbulent flow, tur- bulent mixing can cause extra attenuation of the sound waves in addition to that caused by the viscothermal eects. Experiments show that compared to the vis- cothermal eects, turbulent absorption becomes the dominant contribution to the sound attenuation at suciently low frequencies. READ MORE