Search for dissertations about: "stall"

Showing result 1 - 5 of 33 swedish dissertations containing the word stall.

  1. 1. Vertical Axis Wind Turbines Electrical System and Experimental Results

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Jon Kjellin; Hans Bernhoff; Mats Leijon; Jonny Hylander; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; H-rotor; start-up; all-electric control; Power Coefficient; stall; tip speed ratio; Renewable energy; Measurement systems; PM-generator;

    Abstract : The wind power research at the division of Electricity at Uppsala University is aimed towards increased understanding of vertical axis wind turbines. The considered type of wind turbine is an H-rotor with a directly driven synchronous generator operating at variable speed. READ MORE

  2. 2. Numerical simulation of viscous compressible flows applied to turbomachinery blade flutter

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : L. D. Gunnar Sidén; [1991]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; unsteady; flutter; turbine; aeroengine; turbomachinery; numerical method; oscillating; Navier-Stokes; finite volume; viscious; finite element; turbulent; fan; aeroelastic; vibration; compressor; stall;

    Abstract : .... READ MORE

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

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Eduard Dyachuk; Hans Bernhoff; Sandra Eriksson; Anders Goude; Mac Gaunaa; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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;

    Abstract : 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. READ MORE

  4. 4. Flow instabilities in centrifugal compressors at low mass flow rate

    University dissertation from Kungliga Tekniska högskolan : Kungliga Tekniska högskolan

    Author : Elias Sundström; Mihai Mihaescu; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal compressor; flow instabilities; rotational flows; rotating stall; surge; compressible Large Eddy Simulation; Teknisk mekanik; Engineering Mechanics;

    Abstract : 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). READ MORE

  5. 5. Modeling and Linear Quadratic Optimal Control of Wind Turbines

    University dissertation from Kungliga Tekniska högskolan : Kungliga Tekniska högskolan

    Author : Thommy Ekelund; [1997]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic system; structural dynamics; yaw control; variable speed; wind turbines; active stall; estimation; LQG; identification;

    Abstract : Control can improve the performance of wind turbines by enhancing the energy capture and reducing dynamic, as well as static, loads. There are several possible configurations of the control system, depending on the available actuators. READ MORE