Sökning: "dynamic stall"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden dynamic stall.

  1. 1. Aerodynamics of Vertical Axis Wind Turbines : Development of Simulation Tools and Experiments

    Författare :Eduard Dyachuk; Hans Bernhoff; Sandra Eriksson; Anders Goude; Mac Gaunaa; Uppsala universitet; []
    Nyckelord :wind power; vertical axis turbine; H-rotor; simulations; streamtube model; vortex model; dynamic stall; measurements; blade; force; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : This thesis combines measurements with the development of simulation tools for vertical axis wind turbines (VAWT). Numerical models of aerodynamic blade forces are developed and validated against experiments. The studies were made on VAWTs which were operated at open sites. LÄS MER

  3. 2. Dynamic Models of Wind Turbines

    Författare :Abram Perdana; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency stability; variable-speed; modeling; power system stability; validation; aggregated model; fixed-speed; voltage stability; wind turbine;

    Sammanfattning : The impact of wind power generation in the power system is no longer negligible. Therefore, there is an urgent need for wind turbine models that are capable of accurately simulating the interaction between wind turbines or wind farms and the power system. LÄS MER

  4. 3. Rethinking Dynamic Instruction Scheduling and Retirement for Efficient Microarchitectures

    Författare :Mehdi Alipour; David Black-Schaffer; Stefanos Kaxiras; Mikko H. Lipasti; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Out-of-Order Processors; Energy-Efficient; High-Performance; Instruction Scheduling; Computer Science; Datavetenskap;

    Sammanfattning : Out-of-order execution is one of the main micro-architectural techniques used to improve the performance of both single- and multi-threaded processors. The application of such a processor varies from mobile devices to server computers. LÄS MER

  5. 4. Aerodynamic Studies of Vertical Axis Wind Turbines using the Actuator Line Model

    Författare :Victor Mendoza; Anders Goude; Hans Bernhoff; Robert Flemming Mikkelsen; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  7. 5. Flow instabilities in centrifugal compressors at low mass flow rate

    Författare :Elias Sundström; Mihai Mihaescu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal compressor; flow instabilities; rotational flows; rotating stall; surge; compressible Large Eddy Simulation; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : A centrifugal compressor is a mechanical machine with purpose to convert kineticenergy from a rotating impeller wheel into the fluid medium by compressingit. One application involves supplying boost air pressure to downsized internalcombustion engines (ICE). LÄS MER