Search for dissertations about: "Global Flows"

Showing result 1 - 5 of 180 swedish dissertations containing the words Global Flows.

2. 1. The Story of Phosphorus : Sustainability implications of global phosphorus scarcity for food security

   Author : Dana Cordell; Stuart White; Jan-Olof Drangert; Julie Wilk; Johan Rockström; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; global phosphorus scarcity; peak phosphorus; global food security; sustainable resource use; food production and consumption system; transdisciplinary; systems thinking; global fosforbrist; peak fosfor; global matsäkerhet; hållbar resursanvändning; system för produktion och konsumtion av mat; transdisciplinaritet; systemtänkande; Water in nature and society; Vatten i natur och samhälle;

   Abstract : The story of phosphorus began with the search for the philosopher’s stone, and centuries later the critical role of phosphorus in soil fertility and crop growth was highlighted. Eventually, phosphorus was implicated in the global environmental challenge of eutrophication. READ MORE

4. 2. Global stability and feedback control of boundary layer flows

   Author : Espen Åkervik; Dan S. Henningson; Luca Brandt; Dwight Barkley; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stability; Global Stability; Feedback Control; Control; Estimation; Absolute Convective Instabilities; Model Reduction; Fluid mechanics; Strömningsmekanik;

   Abstract : In this thesis the stability of generic boundary layer flows is studied from a global viewpoint using optimization methods. Global eigenmodes of the incompressible linearized Navier-Stokes equations are computed using the Krylov subspace Arnoldi method. READ MORE

5. 3. Global stability analysis of three-dimensional boundary layer flows

   Author : Mattias Brynjell-Rahkola; Dan Henningson; Philipp Schlatter; Ardeshir Hanifi; Spencer Sherwin; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic stability; transition to turbulence; global analysis; boundary layers; roughness; laminar flow control; Stokes Laplace preconditioner; optimal forcing; crossflow vortices; Ginzburg-Landau; Falkner-Skan-Cooke; Blasius; lid-driven cavity;

   Abstract : This thesis considers the stability and transition of incompressible boundary layers. In particular, the Falkner–Skan–Cooke boundary layer subject to a cylindrical surface roughness, and the Blasius boundary layer with applied localized suction are investigated. READ MORE

6. 4. Space-adaptive simulation of transition and turbulence in shear flows

   Author : Daniele Massaro; Philipp Schlatter; Saleh Rezaeiravesh; Alfredo Pinelli; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; global stability; coherent structures; adaptive mesh refinement; Turbulens; global stabilitet; koherenta strukturer; adaptiv nätförfining; Teknisk mekanik; Engineering Mechanics;

   Abstract : Transitional and turbulent shear flows are ubiquitous, from the boundary layer developing on an aeroplane wing to the flow within the aortic arch. In this thesis, we study wall-bounded and free shear flows through direct numerical simulations. READ MORE

7. 5. Analysis and control of transitional shear flows using global modes

   Author : Shervin Bagheri; Dan Henningson; Alessandro Bottaro; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; flow control; hydrodynamic stability; global modes; jet in crossflow; flat-plate boundary layer; laminar-turbulent transition; Arnoldi method; Koopman modes; balanced truncation; direct numerical simulations.; Fluid mechanics; Strömningsmekanik;

   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