Sökning: "flat-plate boundary layer"
Visar resultat 6 - 10 av 38 avhandlingar innehållade orden flat-plate boundary layer.
6. Receptivity of Boundary-Layer Flows over Flat and Curved Walls
Sammanfattning : 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. LÄS MER
7. Boundary layer streaks as a novel laminar flow control method
Sammanfattning : A novel laminar flow control based on generation of spanwise mean velocity gradients (SVG) in a flat plate boundary layer is investigated where disturbances of different types are introduced in the wall-bounded shear layer. The experimental investigations are aimed at; (i) generating stable and steady streamwise streaks in the boundary layer which set up spanwise gradients in the mean flow, and (ii) attenuating disturbance energy growth in the streaky boundary layers and hence delaying the onset of turbulence transition. LÄS MER
8. Flow control and reduced-order modelling of transition in shear flows
Sammanfattning : In this thesis direct numerical simulation is used to investigate the possibility to delay the transition from a laminar to a turbulent flow in boundary layer flows. Furthermore, modal analysis techniques are used to identify the coherent structures in wind turbine wake. LÄS MER
9. On stability and receptivity of boundary-layer flows
Sammanfattning : This work is concerned with stability and receptivity analysis as well as studies on control of the laminar-turbulent transition in boundary-layer flows through direct numerical simulations. Various flow configurations are considered to address flow around straight and swept wings. LÄS MER
10. Attenuation of boundary layer disturbances by means of streamwise vortices
Sammanfattning : The stability of the boundary layer developed on a flat plate is studied in the presence of streamwise streaks where disturbances of different types are introduced in the wall-bounded shear layer. The experimental investigations are aimed at flow control by means of passively damping the energy growth of the disturbances in the streaky boundary layer and furthermore delay the onset of the transition in the streamwise direction. LÄS MER