Sökning: "flat plate"
Visar resultat 6 - 10 av 72 avhandlingar innehållade orden flat plate.
6. Measurements and Prediction of Friction Drag of Rough Surfaces
Sammanfattning : Owing to the increased sea transportation of goods, the environmental impacts of this activity are becoming more and more important, since a ship experiences resistance that directly affects its performance and fuel consumption. The growth of marine organisms (fouling) on ship hulls increases the roughness of the hull surface, which in turn causes a rise in ship resistance with a consequent increase in fuel consumption and greenhouse emissions of up to 40%. LÄS MER
7. 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
8. 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
9. Study of adverse-pressure-gradient effects on a flat-plate boundary layer at high Reynolds numbers
Sammanfattning : Turbulent boundary layers are present in many aspects of life, from the weather and wind currents to transportation, production of energy or mixing processes. Understanding turbulent motions can allow for an improvement and development of technical devices, techniques or diagnosis of phenomena where a fluid flow is in the turbulent regime. LÄS MER
10. Analysis and control of transitional shear flows using global modes
Sammanfattning : 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. LÄS MER