Search for dissertations about: "Wind turbine wake"

Showing result 6 - 10 of 34 swedish dissertations containing the words Wind turbine wake.

2. 6. Numerical computations of wind turbine wakes and wake interaction : Optimization and control

   Author : Karl Nilsson; Dan Henningson; Stefan Ivanell; Martin O. L. Hansen; KTH; []
   Keywords : Actuator disc method; Actuator line method; Blade element momentum method; Wind turbine wake; Wake interaction; CFD; LES; EllipSys3D;

   Abstract : In the present thesis the wake flow behind wind turbines is analyzed numerically using large-eddy simulations. The wind turbine rotors are modeled by using either the actuator disc method or the actuator line method in which the blades are represented by body forces computed with airfoil data. READ MORE

4. 7. Numerical Computations of Wakes Behind Wind Farms

   Author : Ola Eriksson; Stefan Ivanell; Simon-Philippe Breton; Anna Rutgersson; Dan Henningson; Niels Troldborg; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Wind turbine; Wind power; Wind farm; Wakes; Long distance wakes; Farm-Farm; Farm to farm interaction; Wind farm cluster; Large Eddy simulations; LES; Actuator disc method; ACD; CFD; Ellipsys3D;

   Abstract : More and larger wind farms are planned offshore. As the most suitable build sites are limited wind farms will be constructed near to each other in so called wind farm clusters. Behind the wind turbines in these farms there is a disrupted flow of air called a wake that is characterized by reduced wind speed and increased turbulence. READ MORE

5. 8. Numerical Computations of Wakes Behind Wind Farms : A tool to study Farm to Farm interaction

   Author : Ola Eriksson; Stefan Ivanell; Anna Rutgersson; Simon-Philippe Breton; Philippe Chatelain; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Wind turbine; Wind power; Wind farm; Wakes; Long distance wakes; Farm-Farm; Farm to farm interaction; Wind farm cluster; Large Eddy simulations; LES; Actuator disc method; ACD; CFD; Ellipsys3D; Prescribed boundary layer; PBL; Forced boundary layer; FBL; Meteorologi; Meteorology;

   Abstract : More and larger wind farms are planned offshore. As the most suitable sites to build are limited these new wind farms will be constructed near to each other in so called wind farm clusters. Behind the wind turbines in these farms there is a disrupted flow of air called a wake that is characterized by reduced wind speed and increased turbulence. READ MORE

6. 9. Wind-turbine wake flows - Effects of boundary layers and periodic disturbances

   Author : Ylva Odemark; Jens Fransson; Per-Åge Krogstad; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind power; wind-turbine model; wind tunnel; porous disc; hot-wire anemometry; particle image velocimetry; blade element momentum method; large eddy simulations; actuator disc method;

   Abstract : The increased fatigue loads and decreased power output of a wind turbine placed in the wake of another turbine is a well-known problem when building new wind-power farms and a subject of intensive research. These problems are caused by the velocity gradients and high turbulence levels present in the wake of a turbine. READ MORE

7. 10. Experimental studies of wind turbine wakes : power optimisation and meandering

   Author : Davide Medici; Henrik Alfredsson; Martin O.L. Lansen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind energy; power optimisation; active control; yaw; vortex shedding; wake meandering; Fluid mechanics; Strömningsmekanik;

   Abstract : Wind tunnel studies of the wake behind model wind turbines with one, two and three blades 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 and particle image velocimetry (PIV) have been used to map the flow field downstream as well as upstream the turbine. READ MORE