Experimental investigation of transonic buffet on swept wings: A comparative study between 2D and 3D flow and analysis of sweep angle influence using stereoscopic PIV and Background Oriented Schlieren

Transonic buffet is an aerodynamic instability that appears on aerofoils and wings at certain combinations of Mach number and angle of attack, and which limits the aircraft flight envelope. This thesis project presents an experimental<br/>investigation of buffet employing stereoscopic PIV and Background Oriented Schlieren. By using four...

Experimental Study of Shock-Shock Interactions with Variable Inflow Mach Number

An experimental investigation on shock-shock interactions has been conducted with the aim of studying the transition between Regular (RI) and Mach interactions (MI) under the condition of variable inflow Mach number. The RI contains only oblique shocks while the MI has a quasi-normal shock segment, known as the Mach stem. MI configurations...

On the unsteady development of the flow under transonic Buffet conditions: Experimental study of the interaction of shock and pressure waves using PIV and Schlieren visualization

This thesis presents an experimental study of the unsteady phenomenon known as transonic buffet. Completely developed in the High Speed Lab of the Aerospace Faculty at TU Delft (The Netherlands), the experiments were conducted in the transonic/supersonic wind tunnel TST-27. In order to achieve time and spatial resolution of the phenomenon, high...

Development of a data fusion framework for the aerodynamic analysis of launchers

During the launching vehicles design and their optimization process, the implementing of aerodynamic characteristics (AC) database is quite important. Accuracy of such database determines quality of the pre-flight simulation, trajectory and even the whole design direction. However, the database building process is one of the most challenging...

On the drag reduction of dimpled surfaces in turbulent boundary layers: Proof of concept and identification of flow structure

The drag characteristics and flows structures over flat surfaces with a pattern of shallow rounded spherical dimples were studied. Such dimpled surfaces have been investigated by a small number of researchers in the past, which have shown a potential for drag reduction of a flat plate in a turbulent boundary layer [Kiknadze et al. (2013)]. These...

Characterization of off-stagnation point pyrolysis in plasma flows using optical measurement techniques

After the invention of the rocket mankind saw a new possibility to study the universe and other planets than Earth by space travel. Since then man has achieved to orbit Earth, land on the Moon and Mars. The constant increase in the demands of future space exploration mission make that also the equipment needs to be _t to the task. For example in...

The effect of tripping devices on a shock wave - boundary layer interaction

Shock Wave Boundary Layer Interactions (SWBLIs) occur frequently in supersonic and hypersonic flows and, depending on the strength of the shock wave and the state of the boundary layer, may lead to boundary layer separation. This can result in a multitude of problems, such as an increase in drag, a drop in air intake efficiency and high fatigue...

Experimental Characterization of a Micro-ramp Wake and its Flow Mixing Properties in Supersonic Flow

Micro-ramps are currently being investigated as a means of reducing negative effects of shock wave-turbulent boundary layer interactions. A micro-ramp enhances the mixing of the ow by introducing vortices in the ow, thus energizing the boundary layer to overcome the adverse pressure gradient due to an impinging shock. The effect of changing...

Flow modelling in supersonic flows over surfaces with large roughness heights

Flow over smooth surfaces has been studied ever since the start of aerodynamic research. Non-smooth irregularities in rough walled surfaces will impact on the flow and induce changes in friction and heat transfer. The term 'rough walled' encompasses a range of shapes, ranging from material roughness to wall profiles with heights up to the...

Mean flow analysis and pressure evaluation by means of PIV in transonic baseflow

During atmospheric ascent, flow separation at the base of launch vehicles gives rise to aerodynamic buffeting across the surface of the nozzle (baseflow buffeting). As a result the nozzle experiences fluctuating loads that cause large bending moments which need to be accounted for during its design. Baseflow buffeting prevents the use of new...

Investigation of Gortler vortices in hypersonic flow using Quantitative Infrared Thermography (QIRT) and Tomographic Particle Image Velocimetry (Tomo-PIV)

Aerodynamic heating is one of the driving aspects in hypersonic vehicle design. During take-off and re-entry, high heat loads are encountered for which the appropriate measures have to be considered. In particular during the re-entry phase, high maneuverability of the vehicle is preferred such that reusable (manned) spacecraft can land on...

Evaluation of the One Variable Measured Boundary Condition Method WIN3VE

This thesis is an evaluation of a wall interference correction program called WIN3VE. This program was developed in the 1990s by the National Aerospace Laboratory of the Netherlands (NLR) but never validated. WIN3VE is written for the High Speed Tunnel (HST) in Amsterdam. This wind tunnel is now run by the German and Dutch Wind tunnels (DNW). In...