Search for dissertations about: "Aeroacoustics"

Showing result 16 - 20 of 23 swedish dissertations containing the word Aeroacoustics.

2. 16. Turbomachinery Aeroacoustic Calculations using Nonlinear Methods

   Author : Martin Olausson; Chalmers University of Technology; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear; CFD; Time Spectral; CAA; Ffowcs-Williams Hawkings; Broadband; Time lag; Computational Aeroacoustics; Fan-Noise; Rotor-Stator interaction; Buffer layer; Oscillating sphere; Newton-GMRES; Computational Fluid Dynamics; Acoustic analogies; Sponge; Counter-Rotating Propfan; Harmonic Balance Technique; Tone; FWH; Chorochronic periodicity; Hybrid RANS LES;

   Abstract : Noise regulations for aircraft that fly over populated areas are becoming continuously stricter. This in combination with increasing computational capabilities has boosted interest in aeroacoustic computations in the aerospace industry. READ MORE

4. 17. Numerical investigation of tonal noise sources from centrifugal fan

   Author : Martin Ottersten; Chalmers University of Technology; []
   Keywords : Computational Aeroacoustics; Tonal Noise; Centrifugal Fan; Blade Passing Frequency;

   Abstract : Heating, ventilating, and air conditioning systems (HVAC) are today an important part of many people's life. They provide a sufficient amount of airflow with the correct temperature, quality, and humidity. The negative side is the noise it produces. Many improvements have been made in building development to reduce noise from the environment. READ MORE

5. 18. Thermo-Acoustic Properties in Combustion Chambers

   Author : Guillaume Jourdain; Chalmers University of Technology; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mode Stability Analysis; Computational Aeroacoustics; Screech mode; Arnoldi s Method; Buzz mode; Afterburner; Gas turbine combustor; Combustion instabilities;

   Abstract : Design and analysis methods for gas turbine combustors or afterburners have to be improved in particular regarding the prediction of combustion instabilites. A methodology, which combines the use of a linearized flow solver and an Arnoldi algorithm performing the eigenmode extraction procedure, resolves eigenmodes which are candidates to these instabilities. READ MORE

6. 19. Numerical Methods for Aeroacoustic Analysis of Turbomachinery

   Author : Daniel Lindblad; Chalmers University of Technology; []
   Keywords : NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; Convective Ffowcs Williams - Hawkings Equation; Computational Aeroacoustics; Acoustic Analogy; Von Neumann Stability Analysis; Tonal Noise; CAA; Harmonic Balance Method; Counter Rotating Open Rotor;

   Abstract : Air transportation is today an integral part of many peoples life and it continuously grow to serve more of us in new and ingenious ways. There are however negative sides to this growth as well, such as increased noise around airports and more CO2 emissions, which must be addressed if aviation is to be part of a sustainable future. READ MORE

7. 20. Investigation of Tonal Noise Sources from Centrifugal Fan using Detached Eddy Simulation

   Author : Martin Ottersten; Chalmers University of Technology; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tonal noise.; Low-frequency rotation; Computational aeroacoustics; Blade passing frequency; Centrifugal fan;

   Abstract : Since we spend the majority of our time indoors, heating, ventilation, and air conditioning (HVAC) systems have become a more and more important part of many people´s life. They provide a sufficient amount of airflow with the correct temperature, quality, and humidity. READ MORE