Sökning: "in-duct source"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden in-duct source.

  1. 1. Acoustic source characterisation for non-linear in-duct sources

    Författare :Fredrik Albertson; KTH; []
    Nyckelord :in-duct source; source characterisation; non-linear source; linearity test; hybrid method; IC-engine; muffler; coupling method;

    Sammanfattning : Different ways to model acoustic in-duct sources have beenanalysed. Measurements were conducted on two diesel truckengines. It was found that for steady state oscillations, onecould linearise in the neighbourhood of a given linearisationpoint, i.e. LÄS MER

  3. 2. Acoustic In-duct Characterization of Fluid Machines with Applications to Medium Speed IC-engines

    Författare :Antti Hynninen; Mats Åbom; Hans Bodén; Antonio Torregrosa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; in-duct; acoustic source; source characterization; IC-engine;

    Sammanfattning : The unwanted sound, noise, can lead to health problems, e.g. hearing loss and stress-related problems. A pre-knowledge of noise generation by machines is of great importance due to the ever-shorter product development cycles and stricter noise legislation. LÄS MER

  4. 3. Methods for Modelling and Characterization of In-Duct Sources

    Författare :Hans Rämmal; Hans Bodén; Mats Åbom; Antonio Torregrosa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Methods to characterize acoustic sources in flow ducts have been investigated. In the first part of this thesis a measurement procedure to characterize an air terminal device using an acoustic one-port source model based on the two microphone technique has been tested and validated. LÄS MER

  5. 4. Non-Spherical Particle Interaction in Duct and Jet Flow

    Författare :Ammar Hazim; Matthias Mandø; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid-gas flow; turbulence modulation; duct flow; coaxial jets flow; swirl jet flow; active flow control; synthetics jet; biomass powder; non-spherical particles; PIV measurement; Strömningslära; Fluid Mechanics;

    Sammanfattning : Wood waste is the most popular biomass recourse for many nations. Burned wood can, direct or indirect, release one of the greenhouse gases, carbon dioxide. The process can still be seen as a renewable source of energy since replanting of the trees and crops are consuming nearly the same amount of carbon dioxide through photosynthesis. LÄS MER

  7. 5. Investigation of acoustic source characterisation and installation effects for small axial fans

    Författare :Per-Olof Berglund; KTH; []
    Nyckelord :axial fan; airborne sound; source characterisation; transmission path analysis; in-duct. Spherical harmonics;

    Sammanfattning : Fans are often used in equipment such as home appliances andelectronic equipment where the margin of profit is small butcustomers demands on a low noise level are high. Therefore,methods for predicting the noise emitted by an applicationincluding one or several fans are desirable in order toimprove, accelerate and reduce the cost of low-noise design. LÄS MER