Search for dissertations about: "Dan. S. Henningson"
Showing result 1 - 5 of 24 swedish dissertations containing the words Dan. S. Henningson.
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1. Adaptive and model-based control in laminar boundary-layer flows
Abstract : In boundary-layer flows it is possible to reduce the friction drag by breaking the path from laminar to turbulent state. In low turbulence environments, the laminar-to-turbulent transition is dominated by local flow instabilities – Tollmien-Schlichting (TS) waves – that exponentially grows while being con- vected by the flow and, eventually, lead to transition. READ MORE
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2. Modelling and control of turbulent and transitional flows
Abstract : The dynamics of fluid motion can accurately be described by the Navier– Stokes equations. Manipulating these equations to reduce their complexity but preserving their main characteristics has always been a key research activity in the field of fluid mechanics. READ MORE
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3. Numerical computations of wind turbine wakes
Abstract : Numerical simulations of the Navier-Stokes equations are performed to achieve a better understanding of the behaviour of wakes generated by wind turbines. The simulations are performed by combining the in-house developed computer code EllipSys3D with the actuator line and disc methodologies. READ MORE
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4. Nonlinear dynamics in transitional wall-bounded flows
Abstract : This thesis focuses on numerical studies of subcritical transition to turbulence in shear flows. The thesis employs a framework based on nonlinear dynamics in the subsequent studies. The geometrical approach to subcritical transition pivots the concepts of edge manifold and edge state. READ MORE
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5. Studies on instability and optimal forcing of incompressible flows
Abstract : This thesis considers the hydrodynamic instability and optimal forcing of a number of incompressible flow cases. In the first part, the instabilities of three problems that are of great interest in energy and aerospace applications are studied, namely a Blasius boundary layer subject to localized wall-suction, a Falkner–Skan–Cooke boundary layer with a localized surface roughness, and a pair of helical vortices. READ MORE