The University of Southampton
University of Southampton Institutional Repository

Stability and unsteadiness of transitional shock-wave/boundary-layer interactions in supersonic flows

Sansica, Andrea (2015) Stability and unsteadiness of transitional shock-wave/boundary-layer interactions in supersonic flows University of Southampton, Engineering and the Environment, Doctoral Thesis , 239pp.

Record type: Thesis (Doctoral)


The aim of this research is to study the effect of transition location on the interaction between an oblique shock-wave and a boundary-layer. A large set of direct and large eddy simulations are performed with an in-house high-order fully-parallelised finite difference compressible Navier-Stokes solver to study the inherent instability and unsteady behaviour of laminar, transitional and turbulent interactions. The numerical simulations are compared with the experiments conducted at the Novosibirsk State University as part of the EU-FP7 TFAST project, providing a better understanding of the fundamental mechanisms of the shock-wave/boundary-layer interaction (SWBLI). As well as the characteristics of the interactions, interest is also focused on methods to control the transition location. Three distinct forcing techniques are used to obtain different transition scenarios for a laminar SWBLI at free-stream Mach number of 1.5. An oblique mode breakdown caused by forcing the most unstable eigenmodes, predicted by the local linear stability theory, is compared with a bypass-like transition due to high-amplitude free-stream acoustic disturbances. A non-thermal plasma flow actuation device is also used, however showing a low applicability to supersonic flows due to the high electric power required to trigger transition. Attention is also focused on the response of a laminar shock-induced separation bubble. For both 2D and 3D configurations, a low-frequency response is found for the first time in a laminar SWBLI, even when the separation bubble is only forced internally, therefore supporting the idea that the separated region is influenced by internal mechanisms. The SWBLI is further analysed via linear and nonlinear stability approaches, including local stability theory or parabolised stability equations based tools. The response of the separated region for increasing shock intensities is studied and the stability based tools provide satisfactory results even for largely separated boundary-layers

PDF DoctoralThesis_AndreaSansica_2015.pdf - Other
Download (24MB)

More information

Published date: October 2015
Organisations: University of Southampton, Aerodynamics & Flight Mechanics Group


Local EPrints ID: 385891
PURE UUID: 90a5ecae-519e-4910-b6ca-e124144c818c

Catalogue record

Date deposited: 18 Jan 2016 09:45
Last modified: 17 Jul 2017 19:53

Export record


Author: Andrea Sansica
Thesis advisor: Neil Sandham

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.