Search for dissertations about: "sound generation"

Showing result 21 - 25 of 64 swedish dissertations containing the words sound generation.

  2. 21. Noise, eigenfrequencies and turbulence behavior of a 200 kW H-rotor vertical axis wind turbine

    Author : Erik Möllerström; Jonny Hylander; Fredric Ottermo; Hans Bernhoff; Göran Sidén; Mats Åbom; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; H-rotor; eigenfrequency; semi-guy-wired tower; noise emission; sound power level; microphone array; turbulence intensity; power curve; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Vertical-axis wind turbines (VAWTs) have with time been outrivaled by the today more common and economically feasible horizontal-axis wind turbines (HAWTs). However, VAWTs have several advantages which still make them interesting, for example, the VAWTs can have the drive train at ground level and it has been argued that they have lower noise emission. READ MORE

  4. 22. Predictions of Aerodynamically Induced Wind Noise Around Ground Vehicles

    Author : Jonas Ask; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; side mirror; LES; incompressibility; Curle; CAA; air rush noise; low Mach number; ground vehicle; cavity;

    Abstract : Over the last decade wind noise has with few exceptions consistently generated a constant or even growing level of customer complaints to automotive companies world-wide. This can partly be explained by a relatively greater focus on engine, power-train and tire noise combined with a growing need to reduce weight in future cars. READ MORE

  5. 23. Aeroacoustic Characterization using Multiport Methods

    Author : Andreas Holmberg; Hans Bodén; Mats Åbom; Susann Boij; Lars Enghardt; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aeroacoustics; Multiport; Experiments; Computational Aeroacoustics; Mixer Plate; T-junction.;

    Abstract : Noise is a major environmental pollutant, which can inict physical and psychologicalinjury. An important noise contribution stems from aeroacousticsources, which are found in e.g., ventilation ducts, engine exhaust systems andairplane engines. READ MORE

  6. 24. Computational Techniques for Turbulence Generated Noise

    Author : Mattias Billson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Computational techniques for the noise generated by high Mach number subsonic jets have been investigated. The main focus has been on the hybrid noise prediction method SNGR (Stochastic Noise Generation and Radiation), which is based on unsteady source modeling for the inhomogeneous linearized Euler equations (ILEE). READ MORE

  7. 25. An experimental and numerical study of an automotive cooling module

    Author : Anders Rynell; Gunilla Efraimsson; Michael Shur; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fan installation effects; spectral decomposition; aeroacoustics; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : Heavy vehicles are major emitters of noise. Especially at idle or low vehicle speeds a large portion of the noise emanates from the fan that forces the flow through the cooling module. The aim of this work is to investigate and reveal aerodynamic and acoustic installation effects linked to the cooling package. READ MORE