Sökning: "boundary-layer blowing"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden boundary-layer blowing.
1. Experimental study on turbulent boundary-layer flows with wall transpiration
Sammanfattning : Wall transpiration, in the form of wall-normal suction or blowing through a permeable wall, is a relatively simple and effective technique to control the behaviour of a boundary layer. For its potential applications for laminar-turbulent transition and separation delay (suction) or for turbulent drag reduction and thermal protection (blowing), wall transpiration has over the past decades been the topic of a significant amount of studies. LÄS MER
2. Optimisation and control of boundary layer flows
Sammanfattning : Both optimal disturbances and optimal control are studied by means of numerical simulations for the case of the flat-plate boundary-layer flow. The optimisation method is the Lagrange multiplier technique where the objective function is the kinetic energy of the flow perturbations and the constraints involve the linearised Navier–Stokes equations. LÄS MER
3. Flow control of boundary lagers and wakes
Sammanfattning : Both experimental and theoretical studies have beenconsidered on flat plate boundary layers as well as on wakesbehind porous cylinders. The main thread in this work iscontrol, which is applied passively and actively on boundarylayers in order to inhibit or postpone transition toturbulence; and actively through the cylinder surface in orderto effect the wakecharacteristics. LÄS MER
4. Experimental design and vortex analyses in turbulent wake flows
Sammanfattning : A new experimental setup for studies on wake flow instability and its control that successfully has been designed and manufactured, is introduced and de- scribed. The main body is a dual-sided flat plate with an elliptic leading edge and a blunt trailing edge. LÄS MER
5. Investigations of Flow Conditions in an Automotive Wind Tunnel
Sammanfattning : As vehicle manufacturers seek to shorten the development time of new models, wind tunnel testing of prototype vehicles needs to be partially replaced by virtual simulations. However, this requires thorough validation of the virtual methods, which is done by comparison to wind tunnel tests. LÄS MER