Search for dissertations about: "Free stream turbulence"

Showing result 6 - 10 of 45 swedish dissertations containing the words Free stream turbulence.

  2. 6. A test of turbulence models for a vortex in a free-stream

    Author : Urban Svennberg; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : .... READ MORE

  4. 7. Receptivity of Boundary-Layer Flows over Flat and Curved Walls

    Author : Lars-Uve Schrader; Luca Brandt; Dan Stefan Henningson; Gregoire Casalis; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Boundary-layer receptivity; laminar-turbulent transition; swept-plate boundary layer; Görtler flow; leading-edge effects; swept-wing flow; crossflow vortices; Görtler rolls; disturbance streaks; wall roughness; free-stream turbulence; Fluid mechanics; Strömningsmekanik;

    Abstract : Direct numerical simulations of the receptivity and instability of boundary layers on flat and curved surfaces are herein reported. Various flow models are considered with the aim to capture aspects of flows over straight and swept wings such as wall curvature, pressure variations, leading-edge effects, streamline curvature and crossflow. READ MORE

  5. 8. Study of generation, growth and breakdown of streamwise streaks in a Blasius boundary layer

    Author : Luca Brandt; KTH; []
    Keywords : Fluid mechanics; laminar-turbulent transition; boundary layer flow; transient growth; streamwise streaks; lift-up effect; receptivity; free-stream turbulence; streak instability; secondary instability; Direct Numerical Simulation.;

    Abstract : Transition from laminar to turbulent flow has beentraditionally studied in terms of exponentially growingeigensolutions to the linearized disturbance equations.However, experimental findings show that transition may occuralso for parameters combinations such that these eigensolutionsare damped. READ MORE

  6. 9. Stability analysis and transition prediction of wall-bounded flows

    Author : Ori Levin; KTH; []
    Keywords : Boundary layer; wall jet; algebraic growth; exponential growth; lift-up effect; streamwise streaks; Tollmien-Schlichting waves; free-stream turbulence; roughness element; transition prediction; Parabolized Stability Equations; Direct Numerical S;

    Abstract : Disturbances introduced in wall-bounded .ows can grow andlead to transition from laminar to turbulent .ow. In order toreduce losses or enhance mixing in energy systems, afundamental understanding of the . READ MORE

  7. 10. Stability and transition on wind turbine blades

    Author : Thales Coelho Leite Fava; Ardeshir Hanifi; Dan Henningson; Stefania Cherubini; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Boundary layer stability; free-stream turbulence; laminar-turbulent transition; low-frequency oscillations; rotation effects; wind turbine blades.; Gränsskiktsstabilitet; friströmsturbulens; laminär-turbulent omslag; lågfrekventa svängningar; rotationseffekter; vindkraftverksblad.; Teknisk mekanik; Engineering Mechanics;

    Abstract : Transition on wind turbine blades is a highly complex phenomenon due to the myriad effects influencing the process. This thesis studies some of them, namely free-stream turbulence (FST), rotation, and three-dimensionality. The investigations employ large eddy simulations (LES) with and without (implicit or wall-resolved LES) a subgrid-scale model. READ MORE