Search for dissertations about: "wind regime"

Showing result 1 - 5 of 29 swedish dissertations containing the words wind regime.

  2. 1. Aerodynamic Studies of Vertical Axis Wind Turbines using the Actuator Line Model

    Author : Victor Mendoza; Anders Goude; Hans Bernhoff; Robert Flemming Mikkelsen; Uppsala universitet; []
    Keywords : wind power; vertical axis wind turbines VAWTs ; actuator line model ALM ; dynamic stall model DSM ; atmospheric boundary layer ABL ; wake deflection; atmospheric boundary layer ABL ; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : This thesis addresses the unsteady aerodynamics involved in the operation of vertical axis wind turbines (VAWTs). The main focus is to represent and understand the most relevant phenomena within the resulting flow pattern as the wake structure, loads on the different turbine components and the performance of the rotor. READ MORE

  4. 2. Stability and transition on wind turbine blades

    Author : Thales Coelho Leite Fava; Ardeshir Hanifi; Dan Henningson; Stefania Cherubini; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Boundary layer stability; free-stream turbulence; laminar-turbulent transition; low-frequency oscillations; rotation effects; wind turbine blades.; Gränsskiktsstabilitet; friströmsturbulens; laminär-turbulent omslag; lågfrekventa svängningar; rotationseffekter; vindkraftverksblad.; Teknisk mekanik; Engineering Mechanics;

    Abstract : Transition on wind turbine blades is a highly complex phenomenon due to the myriad effects influencing the process. This thesis studies some of them, namely free-stream turbulence (FST), rotation, and three-dimensionality. The investigations employ large eddy simulations (LES) with and without (implicit or wall-resolved LES) a subgrid-scale model. READ MORE

  5. 3. Atmosphere-ocean Interactions in Swell Dominated Wave Fields

    Author : Alvaro Semedo; Anna Rutgersson; Oyvind Saetra; Piero Lionello; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Waves; Wind sea; Swell; Swell propagation; MABL; Air-sea interaction; Momentum flux; Wave climate; Coupling; Wave age; Empirical Orthogonal functions; Wave model; Climate model; WAM; RCA; wave heights; Meteorology; Meteorologi; Meteorologi; Meteorology;

    Abstract : Ocean wind waves represent the atmosphere-ocean boundary, playing a central role in the air-sea exchanging processes. Heat, mass and momentum are transferred across this boundary, with waves mediating the exchange of principally the momentum between the winds and the ocean surface. During the generation process waves are called wind sea. READ MORE

  6. 4. Implementation and Analysis of Air-Sea Exchange Processes in Atmosphere and Ocean Modelling

    Author : Björn Carlsson; Anna Rutgersson; Ann-Sofi Smedman; Öyvind Saetra; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sensible heat flux; Latent heat flux; Momentum flux; Wind stress; Marine boundary layer; Air–Sea interaction; Swell; Climate model; Ocean model; Roughness parameter; Drag coefficient; Wave breaking; Meteorology; Meteorologi;

    Abstract : To understand and to predict the weather and climate, numerical models are important tools and it is crucial that the controlling processes are described correctly. Since 70% of the global surface is covered with water the description how the ocean and atmosphere communicates has a considerable impact. READ MORE

  7. 5. Feathers by day, membranes by night - Aerodynamic performance in bird and bat flight

    Author : Florian Muijres; Evolutionär ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; animal flight; aerodynamics; vortex wake; actuator disk; flight performance; span efficiency; bird; bat; wind tunnel; PIV; Pied Flycatcher; Glossophaga soricina; Leptonycteris yerbabuenae;

    Abstract : The efficiency and performance of a flying animal is directly related to the aerodynamics around its body and flapping wings. Here, I have developed methods for quantifying the wake dynamics around a flying animal. The results are used to estimate the aerodynamic performance of flapping flight. READ MORE