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Showing result 1 - 5 of 34 swedish dissertations matching the above criteria.

  2. 1. Aeroacoustic Prediction for Vertical Axis Wind Turbines

    Author : Aya Aihara; Hans Bernhoff; Anders Goude; Mats Åbom; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid; acoustics; noise; sound; wind energy; vertical axis wind turbine; aerodynamics; airfoil; simulations; CFD; LES;

    Abstract : This thesis investigates the aerodynamic and aeroacoustic prediction of vertical axis wind turbines, using computational fluid dynamics simulations. Noise pollution from wind turbines is one of the disadvantages of wind energy, calling for strategies to reduce noise levels. READ MORE

  4. 2. CFD of Duct Acoustics for Turbocharger Applications

    Author : Emma Alenius; Mats Åbom; Laszlo Fuchs; Federico Piscaglia; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aero acoustics; Large Eddy Simulation; IC-engines; 1D models; turbocharger; orifice plate; Acoustics; Akustik; Fluid mechanics; Strömningsmekanik;

    Abstract : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. In this work the main focus is the turbocharger compressor and a discussion of turbocharger acoustics and earlier work within the area is presented, giving an insight into its sound generating mechanisms and the damping effect it has on pressure pulses, i. READ MORE

  5. 3. Flow Duct Acoustics : An LES Approach

    Author : Emma Alenius; Mats Åbom; Laszlo Fuchs; Oliver Paschereit; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aero-acoustics; duct-acoustics; sound generation; acoustic scattering; acoustic-flow interaction; LES; IC-engines; orifice plate; confined jet;

    Abstract : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. Simulations are an important tool for enhanced understanding; they give insight into the flow-acoustic interaction in components where it is difficult to perform measurements. READ MORE

  6. 4. Masking of wind turbine sound by ambient noise

    Author : Karl Bolin; Mats Åbom; Sten Ljunggren; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

    Abstract : The main objective of this work was to gain an increasing understanding of the properties of vegetation noise and also to the relative ratios of different natural ambient noises to mask wind turbine sound. A discrete vegetation noise model was developed and compared to an earlier model showing improved estimations, especially at frequencies below 0. READ MORE

  7. 5. Wind Turbine Noise and Natural Sounds : Masking, Propagation and Modeling

    Author : Karl Bolin; Mats Åbom; Jens Forssén; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind turbine noise; models of natural sound sources; masking; Acoustics; Akustik;

    Abstract : Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. READ MORE