Sökning: "Vertical axis turbine"

Visar resultat 11 - 15 av 29 avhandlingar innehållade orden Vertical axis turbine.

  1. 11. High-Performance Finite Element Methods : with Application to Simulation of Diffusion MRI and Vertical Axis Wind Turbines

    Författare :Van-Dang Nguyen; Johan Hoffman; Johan Jansson; Axel Målqvist; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; High performance finite element method; computational diffusion MRI; turbulent flow; vertical axis wind turbine.; Computer Science; Datalogi;

    Sammanfattning : The finite element methods (FEM) have been developed over decades, and together with the growth of computer engineering, they become more and more important in solving large-scale problems in science and industry. The objective of this thesis is to develop high-performance finite element methods (HP-FEM), with two main applications in mind: computational diffusion magnetic resonance imaging (MRI), and simulation of the turbulent flow past a vertical axis wind turbine (VAWT). LÄS MER

  3. 12. Electrical System for a Variable Speed Vertical Axis Wind Turbine

    Författare :Senad Apelfröjd; Uppsala universitet; []
    Nyckelord :;

    Sammanfattning : The wind has been used as a source of energy for a long time. Wind power in power production has had a upswing in the last decade due to its renewable and clean nature. This thesis contributes to the wind power research done at the division of Electricity at Uppsala University. LÄS MER

  4. 13. High Performance Finite Element Methods with Application to Simulation of Vertical Axis Wind Turbines and Diffusion MRI

    Författare :Van Dang Nguyen; Johan Hoffman; Johan Jansson; Mats Larson; KTH; []
    Nyckelord :High performance finite element method; computational diffusion MRI; turbulent flow; vertical axis wind turbine; Cloud computing.; högprestanda finita elementmetod; beräkningsdiffusionsmagnetresonanstomografi; turbulent flöde; vertikalaxlad vindturbin; datormolnberäkning; Tillämpad matematik och beräkningsmatematik; Applied and Computational Mathematics; Biological Physics; Biologisk fysik; Computer Science; Datalogi; Engineering Mechanics; Teknisk mekanik; Mathematics; Matematik; Biological and Biomedical Physics; Biologisk och biomedicinsk fysik;

    Sammanfattning : Finite element methods have been developed over decades, and together with the growth of computer power, they become more and more important in dealing with large-scale simulations in science and industry.The objective of this thesis is to develop high-performance finite element methods, with two concrete applications: computational fluid dynamics (CFD) with simulation of turbulent flow past a vertical axis wind turbine (VAWT), and computational diffusion magnetic resonance imaging (CDMRI). LÄS MER

  5. 14. Wind-turbine wakes - Effects of yaw, shear and turbine interaction

    Författare :Elektra Kleusberg; Dan Henningson; Philipp Schlatter; Stefan Ivanell; Johan Meyers; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind-turbine wakes; yaw; tip-vortex breakdown; shear; computational fluid dynamics; actuator-line method; spectral-element method; Vindturbinsvakar; girning; turbulent nedbrott hos spetsvirvlar; skjuvning; vakinteraktion; beräkningsströmningsdynamik; actuator line-metod; spektralelementmetod; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : The actuator-line method is used together with the incompressible Navier–Stokes equations to investigate the flow development behind wind turbines. Initial investigations focus on providing a thorough validation of the implementation in the spectral-element flow solver Nek5000 against existing numerical and experimental datasets. LÄS MER

  7. 15. A Generator Perspective on Vertical Axis Wind Turbines

    Författare :Fredrik Bülow; Hans Bernhoff; Jens Sørensen; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; PM generator; Wind power; Stator core loss;

    Sammanfattning : The wind energy conversion system considered in this thesis is based on a vertical axis wind turbine with a cable wound direct drive PM generator. Diode rectifiers are used to connect several such units to a single DC-bus and a single inverter controls the power flow from the DC-bus to a utility grid. LÄS MER