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Visar resultat 1 - 5 av 63 avhandlingar som matchar ovanstående sökkriterier.

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

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

    Sammanfattning : 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. LÄS MER

  3. 2. Numerical Study of Fluid-Structure Interaction with Application to Oscillating Cylinders

    Författare :Mikhail Lazarkov; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lock-in.; Thermal engineering; applied thermodynamics; Termisk teknik; termodynamik; synchronization; flow-induced vibration; LES; Volume of Solid method; Virtual Boundary method; vortex-shedding; confined cylinder; Fluid-structure interaction; wake;

    Sammanfattning : The problem of fluid-structure interaction, occurring in many industrial and engineering applications, are of great importance, since interaction of a flow and a structure in it can lead to serious damages of the structure. The fluid-structure interaction gives rise to a variety of different physical phenomena such as flow-induced vibration, noise generation, etc. LÄS MER

  4. 3. Numerical study on instability and interaction of wind turbine wakes

    Författare :Sasan Sarmast; Dan. S. Henningson; Per-Åge Krogstad; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind turbine wakes; Stability; interaction; POD; DMD; Teknisk mekanik; Engineering Mechanics;

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

  5. 4. Numerical study on instability and interaction of wind turbine wakes

    Författare :Sasan Sarmast; Dan S. Henningson; Per-Åge Krogstad; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Turbines; CFD; EllipSys3D; Actuator Line; Stability; Wake; Vortex Model; SRA - E-Science SeRC ; SRA - E-vetenskap SeRC ;

    Sammanfattning : The optimization of new generation of the wind farms is dependent on our understanding of wind turbine wake development, wake dynamics and the interaction of the wakes. The overall goal of the optimization is decreasing the fatigue loading and increasing the power production of the wind farms. LÄS MER

  7. 5. Numerical optimization of hull/propeller/rudder configurations

    Författare :Kaijia Han; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fuel cost savings; optimization; pressure fluctuation; self-propulsion; RANS; verification and validation; cavitation; open water; lifting surface; hull-propeller-rudder; effective wake; efficiency; aspect ratio; lifting line; interaction;

    Sammanfattning : The new framework of the global economy has stimulated and expanded the shipbuilding and shipping industry, especially in Asia in the twenty-first century. This induces urgent and high requirements on designing and building both conventional and new types of ships with high performance, such as high speed, manoeuvrability, seaworthiness and so on. LÄS MER