Use this URL to cite or link to this record in EThOS:
Title: Viscous-inviscid interaction on moving walls
Author: Kirsten, Julius
ISNI:       0000 0004 7223 5925
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
This thesis consists of two parts. In part I, the viscous-inviscid interaction in su- personic flows over down- and upstream moving walls is analysed. The separation is assumed to be provoked by an impinging shock or expansion wave. For large val- ues of the Reynolds number and under the assumption that the speed of the wall is [Mathematical equation appears here. To view, please open pdf attachment], the interaction is described by the classical triple deck theory. For the case [Mathematical equation appears here. To view, please open pdf attachment], the Navier-Stokes equations are analysed in a vicinity of the separation point using the method of matched asymptotic expansions. In chapter 2, the linearised interaction problem for a downstream moving wall is stud- ied and the upstream influence of small perturbations is shown to be exponentially decaying. Moreover, it is found that small perturbations to the skin friction decay alge- braically downstream. The focus then shifts towards the fully non-linear problem, when the strength of the impinging shock wave is of [Symbol appears here. To view, please open pdf attachment], and it is shown numerically that a singularity, indicative of separation, develops at the outer edge of the viscous sublayer. In chapter 3, supersonic flow over an upstream moving wall is considered for which the development of a singularity is observable in the non-linear problem, when the imping- ing shock wave is replaced by an expansion wave. Part II consists of chapter 4, in which hypersonic flows are investigated. In this case the viscous-inviscid interaction extends over the entire body surface and is described by a two-layer model. On motionless and downstream moving walls, the solution to the interaction problem near the leading edge is not unique and there exists an alge- braic upstream influence of perturbations. The associated eigenvalue problem near the leading edge is solved numerically using an iterative procedure and it is shown that the upstream influence becomes smaller as the speed of the wall is increased.
Supervisor: Ruban, Anatoly Sponsor: Engineering and Physical Sciences Research Council
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral