Effect of Single and Periodic Disturbances on Intermittency in Pipe Flow

Author: Vallerani, Ernesto

Year: 1964

Degree: Engineer's thesis

Advisors: Coles, Donald Earl; Roshko, Anatol

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/JX74-BC68

Abstract

A set of experiments has been performed to investigate the behaviour of intermittency in pipe flow, particularly in response to periodical disturbances at fixed frequency (up to 360 cycles per minute) which were introduced in the flow.

The effects were studied at various values of Reynolds number in the transition range from Re = 2000 to 3000.

The main object was to relate the input frequency of the disturbance to the output frequency of the turbulent slugs emerging at the end of the pipe (Part III. C).

The propagation velocity of the interfaces separating regions of laminar and turbulent flow was studied by performing experiments with a single disturbance (Part III. B).

A single experiment has been performed also to investigate the frequency and the intermittency of the turbulent slugs of a flow with a fixed, geometrical perturbation at the inlet (Part III. A).

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