Search for dissertations about: "aeroakustik"

Found 3 swedish dissertations containing the word aeroakustik.

2. 1. Frequency Domain Linearized Navier-Stokes Equations Methods for Low Mach Number Internal Aeroacoustics

   Author : Axel Kierkegaard; Gunill Efraimsson; Christophe Schram; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

   Abstract : Traffic is a major source of environmental noise in modern day's society. As a result, the development of new vehicles are subject to heavy governmental legislations. The major noise sources on common road vehicles are engine noise, transmission noise, tire noise and, at high speeds, wind noise. READ MORE

4. 2. Frequency Domain Linearized Navier-Stokes Equations Methodology for Aero-Acoustic and Thermoacoustic Simulations

   Author : Wei Na; Gunilla Efraimsson; Susann Boij; Martinez Lera Paula; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Linearized Navier-Stokes Equations; frequency domain; fluid equivalent model; hybrid liner; thermoacoustic instabilities; Rijke-tube; Engineering Mechanics; Teknisk mekanik;

   Abstract : The first part of the thesis focuses on developing a numerical methodology to simulate the acoustic properties of a hybrid liner consisting of a perforated plate, a porous layer and a Helmholtz cavity. Liners are always a standard way to reduce noise in today’s aeroengines, e.g. READ MORE

5. 3. Sound propagation from sustainable ground vehicles : from aeroacoustic sources to urban noise

   Author : Nicolas Pignier; Ciarán O'Reilly; Susann Boij; Gwenael Gabard; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound propagation; sound generation; ground vehicle; aeroacoustics; aerodynamics; Kirchhoff approximation; detached eddy simulation; Ffowcs Williams and Hawkings; ljudutberdning; ljudalstring; markfordon; aeroakustik; aerodynamik; Kirchhoff approximation; detached eddy simulation; Ffowcs Williams and Hawkings; Vehicle and Maritime Engineering; Farkostteknik; Engineering Mechanics; Teknisk mekanik;

   Abstract : Transportation is the main source of environmental noise in Europe, with an estimated 125 million people affected by excessive noise levels from road traffic, causing a burden of noise related diseases and having a substantial economic impact on society. In order to reduce exposure to high levels of traffic noise, two approaches are the topic of extensive research: preventing sound from propagating from roads and railways using for example noise barriers, and reducing the sources of noise themselves. READ MORE