Search for dissertations about: "Wim De Roeck"

Found 3 swedish dissertations containing the words Wim De Roeck.

  2. 1. A Wave Expansion Method for Aeroacoustic Propagation

    Author : Johan Hammar; Gunilla Efraimsson; Ciarán J. O'Reilly; Wim De Roeck; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

  4. 2. Experimental Investigation of the Acoustic Properties of Perforate using Acoustic Three-Ports

    Author : Shail A. Shah; Susann Boij; Hans Bodén; Wim De Roeck; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duct Acoustics; Acoustical Three-port; Perforated plate; Transfer Impedance; Scattering Matrix; Grazing Flow; High-level Excitation; Non-linear effects; Flow-Acoustic Interaction; Rectangular T-Junction; Farkostteknik; Vehicle and Maritime Engineering;

    Abstract : This thesis discusses the aero-acoustic characterisation of a perforate sample using a three-port technique. A rectangular T-junction with a flush mounted perforated sample at the intersection form the acoustical three-port. READ MORE

  5. 3. Acoustic characterization of orifices and perforated liners with flow and high-level acoustic excitation

    Author : Lin Zhou; Hans Bodén; Wim De Roeck; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bias Flow; Grazing Flow; Nonlinear Acoustics; Acoustic Impedance; Impedance Eduction; Single Mode Straightforward Method; Uncertainty Analysis; LEE; LNSE; Järnvägsgruppen - Ljud och vibrationer; Järnvägsgruppen - Ljud och vibrationer;

    Abstract : This thesis is motivated by the need for noise control in aircraft engine with orifices and perforated liner. The presence of high-level acoustic excitation, different flow situations either bias flow, grazing flow or any combination in the aircraft engine, makes the acoustic behavior complex due to the interaction between sound and flow over the lined wall. READ MORE