Sökning: "wind turbine blades"

Visar resultat 1 - 5 av 44 avhandlingar innehållade orden wind turbine blades.

  1. 1. Numerical computations of wind turbine wakes

    Författare :Stefan S. A. Ivanell; Dan Henningsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; Wind Energy; Wind Turbine; Wake; Circulation; Vortex; CFD; EllipSys3D; Actuator line; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Numerical simulations using CFD methods are performed for wind turbine applications. The aim of the project is to get a better understanding of the wake behaviour, which is needed since today’s industrial design codes for wind power applications are based on the BEM (Blade Element Momentum) method. LÄS MER

  3. 2. Stability and transition on wind turbine blades

    Författare :Thales Coelho Leite Fava; Ardeshir Hanifi; Dan Henningson; Stefania Cherubini; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 3. Aerolastic simulation of wind turbine dynamics

    Författare :Anders Ahlström; Anders Eriksson; Martin O. L. Hansen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; wind turbine; aeroelastic modelling; rotor aerodynamics; structural dynamics; MSC.Marc; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : The work in this thesis deals with the development of an aeroelastic simulation tool for horizontal axis wind turbine applications. Horizontal axis wind turbines can experience significant time varying aerodynamic loads, potentially causing adverse effects on structures, mechanical components, and power production. LÄS MER

  5. 4. Wind-turbine wake flows - Effects of boundary layers and periodic disturbances

    Författare :Ylva Odemark; Jens Fransson; Per-Åge Krogstad; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  7. 5. Numerical computations of wind turbine wakes

    Författare :Stefan S. A. Ivanell; Dan Henningson; Peinke Joachim; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Actuator Line Model; Actuator Disc Model; Wind Turbine Wake; CFD; LES; EllipSys3D; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Numerical simulations of the Navier-Stokes equations are performed to achieve a better understanding of the behaviour of wakes generated by wind turbines. The simulations are performed by combining the in-house developed computer code EllipSys3D with the actuator line and disc methodologies. LÄS MER