Search for dissertations about: "Koopman modes"
Showing result 1 - 5 of 6 swedish dissertations containing the words Koopman modes.
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1. Analysis and control of transitional shear flows using global modes
Abstract : In this thesis direct numerical simulations are used to investigate two phenomenain shear flows: laminar-turbulent transition over a flat plate and periodicvortex shedding induced by a jet in cross flow. The emphasis is on understanding and controlling the flow dynamics using tools from dynamical systems and control theory. READ MORE
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2. Active Control and Modal Structures in Transitional Shear Flows
Abstract : Flow control of transitional shear flows is investigated by means of numerical simulations. The attenuation of three-dimensional wavepackets of Tollmien-Schlichting (TS) and streaks in the boundary layer is obtained using active control in combination with localised sensors and actuators distributed near the rigid wall. READ MORE
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3. Spectral-element simulations of turbulent wall-bounded flows including transition and separation
Abstract : The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. READ MORE
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4. Analysis of Flow Structures in Wake Flows for Train Aerodynamics
Abstract : Train transportation is a vital part of the transportation system of today anddue to its safe and environmental friendly concept it will be even more impor-tant in the future. The speeds of trains have increased continuously and withhigher speeds the aerodynamic effects become even more important. READ MORE
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5. The Impact of Non-synchronous Generation on Power Systems Dynamics
Abstract : Due to the increasing integration of Renewable Energy Sources (RES), and the installation of High Voltage Direct Current (HVDC) systems, more power is injected to the AC grid based on power electronic converters. This kind of power injection is called non-synchronous generation in this thesis. READ MORE