Sökning: "Dan Henningson"
Visar resultat 21 - 25 av 51 avhandlingar innehållade orden Dan Henningson.
21. Transition to turbulence in the asymptotic suction boundary layer
Sammanfattning : The focus of this thesis is on the numerical study of subcritical transition to turbulence in the asymptotic suction boundary layer (ASBL). Applying constant homogeneous suction prevents the spatial growth of the boundary layer, granting access to the asymptotic dynamics. LÄS MER
22. On stability of vortices and vorticity generated by actuator lines
Sammanfattning : Vortices are present in nature and in many flows of industrial importance. The stability of configurations of vortices can have real-world consequences, because vortices play a crucial role in accelerated mixing. In particular, vortices are present in the wake of wind turbines and other rotors. LÄS MER
23. Wind turbine simulations using spectral elements
Sammanfattning : Understanding the flow around wind turbines is a highly relevant research question due to the increased interest in harvesting energy from renewable sources. This thesis approaches the topic by means of numerical simulations using the actuator line method and the incompressible Navier–Stokes equations in the spectral element code Nek5000. LÄS MER
24. Wind-turbine wakes - Effects of yaw, shear and turbine interaction
Sammanfattning : The actuator-line method is used together with the incompressible Navier–Stokes equations to investigate the flow development behind wind turbines. Initial investigations focus on providing a thorough validation of the implementation in the spectral-element flow solver Nek5000 against existing numerical and experimental datasets. LÄS MER
25. Numerical studies of transtion in wall-bounded flows
Sammanfattning : Disturbances introduced in wall-bounded flows can grow and lead to transition from laminar to turbulent flow. In order to reduce losses or enhance mixing in energy systems, a fundamental understanding of the flow stability and transition mechanism is important. LÄS MER