Search for dissertations about: "wind turbines"

Showing result 11 - 15 of 182 swedish dissertations containing the words wind turbines.

2. 11. Vertical Axis Wind Turbines : Tower Dynamics and Noise

   Author : Erik Möllerström; Jonny Hylander; Fredric Ottermo; Göran Sidén; Hans Bernhoff; Mats Åbom; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; H-rotor; eigenfrequency; semi-guy-wired tower; noise emission; sound power level;

   Abstract : Vertical axis wind turbines (VAWTs) have with time been outrivaled by the today common and economically feasible horizontal axis wind turbines (HAWTs). However, VAWTs have several advantages such as the possibility to put the drive train at ground level, lower noise emissions and better scaling behavior which still make them interesting for research. READ MORE

4. 12. Wind turbines over a hilly terrain: performance and wake evolution

   Author : Ann Hyvärinen; P. Henrik Alfredsson; Antonio Segalini; Leonardo P. Chamorro; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; wind turbines; complex terrain; wind-tunnel measurements; Strömningsmekanik; vindturbiner; komplex terräng; vindtunnelmätningar; Engineering Mechanics; Teknisk mekanik;

   Abstract : The aim of this licentiate thesis is to investigate wind-turbines placed in a complex-terrain environment. This is done by studying the flow around small-scale wind-turbine models placed over a landscape model with hills, and by comparing the results with corresponding data obtained over a flat terrain model. READ MORE

5. 13. 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

6. 14. Electromechanics of Vertical Axis Wind Turbines

   Author : Morgan Rossander; Sandra Eriksson; Hans Bernhoff; Daniel Karlsson; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind power; Diode rectification; Control; Measurement; Simulation; Electromechanical coupling; vindkraft; diodlikriktning; reglering; mätning; simulering; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Abstract : Wind power is an established mean of clean energy production and the modern horizontal axis wind turbine has become a common sight. The need for maintenance is high and future wind turbines may need to be improved to enable more remote and offshore locations. READ MORE

7. 15. Wind turbine wakes : controland vortex shedding

   Author : Davide Medici; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Energy; Power Optimisation; Active Control; Yaw; Vortex; Mechanical energy engineering; Mekanisk energiteknik;

   Abstract : Wind tunnel studies of the wake behind a model wind turbine have been made in order to get a better understanding of wake development as well as the possibility to predict the power output from downstream turbines working in the wake of an upstream one. Both two-component hot-wire anemometry as well as particle image velocimetry (PIV) have been used to map the flow field. READ MORE