Sökning: "duct system"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden duct system.

  1. 1. 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

  3. 2. Acoustic Characterization of Turbochargers and Pipe Terminations

    Författare :Heiki Tiikoja; Mats Åbom; Francisco Denia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustical two-port; turbocharger; transmission loss; sound generation; compressor; turbine; IC-engine; inlet system; exhaust system; flow duct; duct termination; reflection coefficient;

    Sammanfattning : In search for quieter engines there is a need for a better understanding of the acoustic properties of engine intake and exhaust system components. Besides mufflers which have the purpose of reducing pressure pulses originating from the internal combustion (IC) engine, there are many components in a modern car exhaust and intake system, e.g. LÄS MER

  4. 3. Aerodynamics of an Aeroengine Intermediate Compressor Duct: Effects from an Integrated Bleed System

    Författare :Elias Siggeirsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Intermediate Compressor Duct; S-shaped duct; DDES; Hybrid RANS LES; Dual-time-stepping; Bleed system; rotor off-take; SBES; CFD; Turbomachinery;

    Sammanfattning : With the successful development of high-bypass-ratio turbofan engines, major aerodynamic components have been optimized and continuous efficiency improvements are getting harder to maintain. Therefore, to meet the requirements of lower emission of greenhouse gases, auxiliary modules such as intermediate ducts are receiving increasing interest. LÄS MER

  5. 4. Modelling of low frequency sound in duct networks

    Författare :Stefan Nygård; KTH; []
    Nyckelord :Duct pipe; System network; Wave-guide; Flow; Sound; Noise; Fluid machine; 2-port; 1-port; Active; Passive; Flow separation; Code; Simulation; Low frequency;

    Sammanfattning : .... LÄS MER

  7. 5. Studies of sound generation and propagation in flow ducts

    Författare :Fabrice Ducret; Mats Åbom; Andy Moorhouse; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; two-port; plane wave; HVAC system; tailpipe; exhaust system; flexible duct; pipe; reflection coefficient; impedance; flow noise; vorticity; damping; scaling laws; impedance; transmission loss; perforated plate; slit; non linearity; Acoustics; Akustik;

    Sammanfattning : This thesis contains three papers investigating problems of interest for noise control in ducts. The first part of this thesis treats the sound propagation in rectangular ducts with flexible walls. Various experimental techniques are performed to measure the internal sound propagation and radiation to the surrounding. LÄS MER