Search for dissertations about: "aero acoustics"

Showing result 26 - 29 of 29 swedish dissertations containing the words aero acoustics.

  2. 26. Optimal damping and slow sound in ducts

    Author : Zhe Zhang; Mats Åbom; Hans Bodén; Lars Enghardt; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : The thesis is dedicated to expanding knowledge on two duct acoustic issues including: 1) the optimal damping of low frequency sound and 2) the development and application of ‘slow sound’.To address the first issue, the ‘Cremer impedance’ proposed more than half a century ago has been revisited and further developed. READ MORE

  4. 27. 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. 28. Engineering data exchange for multidisciplinary analysis using embedding technique

    Author : Mattias Nyström; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

    Abstract : The aim of this work is to improve the sharing of Computer Aided Design and Computer Aided Engineering data between different applications by investigating different enabling technologies and developing a integrated design system that make an automated and seamless information exchange for multidisciplinary analysis possible. An embedded approach has been used, which makes the data public with objects that are discrete software components that contain data and are able to manipulate it. READ MORE

  6. 29. High performance adaptive finite element methods for turbulent fluid flow

    Author : Niclas Jansson; Johan Hoffman; Sverker Holmgren; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical analysis; Numerisk analys;

    Abstract : Understanding the mechanics of turbulent fluid flow is of key importance for industry and society as for example in aerodynamics and aero-acoustics. The massive computational cost for resolving all turbulent scales in a realistic problem makes direct numerical simulation of the underlying Navier-Stokes equations impossible. READ MORE