Sökning: "optimal kontroll"
Visar resultat 6 - 10 av 62 avhandlingar innehållade orden optimal kontroll.
6. Optimisation and control of shear flows
Sammanfattning : Transition to turbulence and flow control are studied by means of numerical simulations for different simple shear flows. Linear and non-linear optimisation methods using the Lagrange multiplier technique are employed. LÄS MER
7. Receptivity of crossflow-dominated boundary layers
Sammanfattning : This thesis deals with receptivity mechanisms of three-dimensional, crossflow-dominated boundary layers. The receptivity of two model problems, a swept-flat-plate and a swept-wing boundary layer, is investigated by solving the parabolised stability equations (PSE) as well as by performing direct numerical simulations (DNS). LÄS MER
8. Global stability analysis of three-dimensional boundary layer flows
Sammanfattning : 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. LÄS MER
9. Active Control and Modal Structures in Transitional Shear Flows
Sammanfattning : Flow control of transitional shear flows is investigated by means of numerical simulations. The attenuation of three-dimensional wavepackets of Tollmien-Schlichting (TS) and streaks in the boundary layer is obtained using active control in combination with localised sensors and actuators distributed near the rigid wall. LÄS MER
10. On stability, transition and turbulence in three-dimensional boundary-layer flows
Sammanfattning : A lot has changed since that day on December 17, 1903 when the Wright brothers made the first powered manned flight. Even though the concepts behind flying are unaltered, appearance of stat-of-the-art modern aircrafts has undergone a massive evolution. LÄS MER