A Numerical Investigation into Transonic Flight on Mars Utilizing a 2-D URANS Approach

Interest in powered flight on Mars has been growing in recent years, and as such new developments are being made in determining the effects the Martian atmosphere has on the flow physics and performance, specifically with regards to similarity parameters: the Reynolds number & the Mach number. This paper aimed to investigate whether the...

Transonic Dimples: An experimental study of the flow structures formed at transonic speeds over dimpled surfaces

Dimples are shallow surface indentations that have been recently considered as a passive viscous drag reducing technique for turbulent boundary layers. Studies so far were limited to incompressible low-Re flows and display little consensus on whether dimples can actually produce net improvements in total drag. Conversely, dimple geometry can be...

Oblique Shock Wave-Boundary Layer Interactions Over Porous Plates

This report discusses an investigation into the effect of a porous plate covering a cavity, on an oblique shock wave-boundary layer interaction. Four porous plates with different hole sizes and porosities, as well as a solid, 'dummy', plate, have been tested in a Mach 2 wind tunnel whereby an oblique shock wave (produced by a wedge) impinged on...

Investigation of the Effect of a Surface Protuberance on a High Speed Boundary Layer

One of the major challenges that engineers face when designing a high speed vehicle is aerodynamics heating. While ideally the external surfaces are expected to maintain a smooth profile, this is not the case in most vehicles, which might be laden with discontinuities like steps, gaps, and other protrusions. These could alter the local flow...

The Effect of Nozzle Length and Exhaust Plume on Transonic and Supersonic Axisymmetric Base Flows: An Experimental Study

A combined PIV and Schlieren measurements have been carried out in the transonic-supersonic wind tunnel (TST-27) to investigate the effect of exhaust plume and the variation in nozzle length on the flow topology and mean pressure distribution on the wake of axisymmetric backward facing step model at freestream Mach numbers of 0.76 and 2.20,...

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...

On the scaling and unsteadiness of shock induced separation

Shock wave boundary layer interactions (SWBLI) are a common phenomenon in transonic and supersonic flows. The presence of shock waves, induced by specific geometrical configurations, causes a rapid increase of the pressure, which can lead to flow separation. Examples of such interactions are found in amongst others rocket engine nozzles and on...

Unsteady Flow Organization of a Shock Wave/Boundary Layer Interaction

A fundamental experimental study is carried out to investigate the unsteady flow organization of an incident shock wave/turbulent boundary layer interaction at Mach 2.1. Planar and tomographic particle image velocimetry (PIV) are used in combination with data processing using the proper orthogonal decomposition (POD), complemented with hot-wire...

The effect of particle image blur on the correlation map and velocity measurement in PIV

In PIV particle image blur is usually observed near fluid optical interfaces, i.e. shock waves, and thin flow structure with large density variations, e.g. shear layers and boundary layers. In such an environment the particle image is not only subject to blur, but is also displaced from its actual position due to refraction, which is denoted as...

Liquid slug generator for separated gas/liquid flow in pipes

The goal of the study is to develop a slug generator that can be used upstream of the Multiphase Capacitive Flow meter (MCF) developed by KSEPL. This meter operates only in the intermittent flow regime. The scope of application should be widened to the stratified and stratified annular flow regime by means of a slug generator. Objectives in the...