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On the Stability and Transition of Time Periodic Pipe Flow

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thesis
posted on 29.05.2019, 05:57 authored by JONATHAN RICHARD ALAN NEBAUER
This computational study investigates the transition to turbulence of fluid in a pipe that is subjected to a sinusoidal oscillation. The problem is solved by separating the flow into a laminar base-flow and a linear infinitesimal perturbation. The energy of the perturbation is followed through time-stepper methods, with growth leading towards turbulence, and decay leading to a laminar state. The analysis demonstrates an exponential increase in transient growth of the perturbation as the flow control parameters are varied, a case normally only associated with separated shear flows. The driving mechanism is isolated to a new linear process involving the coordination of two known inviscid instabilities linked to the structure of the laminar base-flow.

History

Campus location

Australia

Principal supervisor

Hugh Maurice Blackburn

Year of Award

2019

Department, School or Centre

Mechanical and Aerospace Engineering

Course

Doctor of Philosophy

Degree Type

DOCTORATE

Faculty

Faculty of Engineering