Search for dissertations about: "Shervin Bagheri"
Showing result 1 - 5 of 12 swedish dissertations containing the words Shervin Bagheri.
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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. Stability analysis and control design of spatially developing flows
Abstract : Methods in hydrodynamic stability, systems and control theory are applied to spatially developing flows, where the flow is not required to vary slowly in the streamwise direction. A substantial part of the thesis presents a theoretical framework for the stability analysis, input-output behavior, model reduction and control design for fluid dynamical systems using examples on the linear complex Ginzburg-Landau equation. READ MORE
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3. Active Control and Reduced-Order Modeling of Transition in Shear Flows
Abstract : In this thesis direct numerical simulation is used to investigate the possibilityto delay the transition from laminar to turbulent in boundary layer flows.Furthermore, modal analysis is used to reveal the coherent structures in highdimensional dynamical systems arising in the flow problems. READ MORE
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4. Transition delay in boundary-layer flows via reactive control
Abstract : Transition delay in boundary-layer flows is achieved via reactive control of flow instabilities, i.e. Tollmien-Schlichting (TS) waves. Adaptive and model-based control techniques are investigated by means of direct numerical simulations (DNS) and experiments. READ MORE
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5. Turbulent flows over permissive boundaries and porous walls
Abstract : This thesis investigates how in wall-bounded turbulent flows changes to the wall can induce changes in the flow. To this end, we investigate the use of wall boundary conditions meant to mimic the effect of textured surfaces. READ MORE