Sökning: "duct-acoustics"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet duct-acoustics.

  1. 1. Flow Duct Acoustics : An LES Approach

    Författare :Emma Alenius; Mats Åbom; Laszlo Fuchs; Oliver Paschereit; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aero-acoustics; duct-acoustics; sound generation; acoustic scattering; acoustic-flow interaction; LES; IC-engines; orifice plate; confined jet;

    Sammanfattning : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. Simulations are an important tool for enhanced understanding; they give insight into the flow-acoustic interaction in components where it is difficult to perform measurements. LÄS MER

  3. 2. CFD of Duct Acoustics for Turbocharger Applications

    Författare :Emma Alenius; Mats Åbom; Laszlo Fuchs; Federico Piscaglia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aero acoustics; Large Eddy Simulation; IC-engines; 1D models; turbocharger; orifice plate; Acoustics; Akustik; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. In this work the main focus is the turbocharger compressor and a discussion of turbocharger acoustics and earlier work within the area is presented, giving an insight into its sound generating mechanisms and the damping effect it has on pressure pulses, i. LÄS MER

  4. 3. Experimental and Numerical Multi-port Eduction for Duct Acoustics

    Författare :Stefan Sack; Abom Mats; Phillip Joseph; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; aeroacoustics; flowacoustics; multi-ports; orifice; silencer; experiment; numeric; IDDES; LNSE; optimization; test rig; Monte Carlo; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : Sound generation and propagation in circular ducts for frequencies beyond the cut-on frequencies of several higher order acoustic modes is investigated. To achieve this, experimental and numerical set-ups are designed and used to research aeroacoustic interactions between in-duct components and to conceive noise mitigation strategies. LÄS MER

  5. 4. Studies of flow duct acoustics with applications to turbocharged engines

    Författare :Hans Rämmal; Hans Boden; Mats Åbom; Antonio Torregrosa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; IC-engine; turbocharger; duct termination; flow duct; exhaust system; inlet system; acoustic source; one-port; two-port; source model; transmission loss; two-port matrix; reflection coefficient; source strength; multi-load method; Acoustics; Akustik;

    Sammanfattning : A number of experimental and theoretical studies, performed in the field of technical flow duct acoustics are presented in this thesis. The acoustical methods treated are implemented on turbocharged IC-engines and engine gas exchange system components. A new method based on the well-known two-load technique has been developed. LÄS MER

  7. 5. Experimental Investigation of the Acoustic Properties of Perforate using Acoustic Three-Ports

    Författare :Shail A. Shah; Susann Boij; Hans Bodén; Wim De Roeck; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER