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Wake interference of two identical oscillating cylinders in tandem: An experimental study

Armin, M, Khorasanchi, M and Day, S (2018) Wake interference of two identical oscillating cylinders in tandem: An experimental study. Ocean Engineering, 166. pp. 311-323. ISSN 0029-8018

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Abstract

This study aims to assess the impact of the spacing between cylinders on their dynamic behaviour. Observations during this experiment have helped to identify the effect of spacing on excitation mechanism of each cylinder as well as establishing the relationship between cylinders response and the spacing between them. Arrays of cylindrical Structures in close proximity are common in variety of engineering structures, particularly in the off-shore industry. If the cylinders are flexible, and are subject to excitation from fluid flow, then the dynamics is influenced by complex interactions between the cylinders, dependent on a variety of parameters. Two cylinders were flexibly mounted in tandem at different spacings from 20D to 3.5D and were towed at different Reynolds numbers ranging from 8.7× 10^3 to 5.2 ×10^4. The gap between cylinders was set to 20, 15, 10, 8, 5, 4, 3.5D respectively; the responses of the cylinders were measured and the mutual interactions were compared. The two cylinders were identical and free to oscillate in both cross-flow and stream-wise directions. The validity of results was examined by comparing to available data in literature and results attained by testing cylinders in-dependently in the towing tank.The interaction of two cylinders are studied through frequency analysis of both cylinders response motion to determine how upstream vortices impact the trailing cylinder response in stream-wise and cross-flow differently.It was observed that leading and trailing cylinders oscillate at different frequencies which is in contrast with results obtained from two fixed cylinders in tandem where both cylinders oscillate at the same frequency.Additionally, it is discussed how spacing controls the excitation mechanism.

Item Type: Article
Uncontrolled Keywords: 0905 Civil Engineering, 0911 Maritime Engineering
Subjects: T Technology > TC Hydraulic engineering. Ocean engineering
T Technology > TJ Mechanical engineering and machinery
Divisions: Maritime & Mechanical Engineering (merged with Engineering 10 Aug 20)
Publisher: Elsevier
Related URLs:
Date Deposited: 05 Sep 2018 09:51
Last Modified: 04 Sep 2021 10:09
DOI or ID number: 10.1016/j.oceaneng.2018.08.012
URI: https://researchonline.ljmu.ac.uk/id/eprint/9161
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