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Publication
Flow-induced motions of flexible filaments hanging in cross-flow
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Authors
Advisor(s)
Abstract(s)
Experiments were carried out to study the dynamics of hanging cantilever flexible filaments in air cross-flow.
Thirteen flexible filaments of 0.61 mm diameter and lengths from 20 mm to 60 mm were tested with wind speeds
in the range of 1–15 m/s, corresponding to Reynolds numbers of 25 < Red < 610 and reduced velocities in the
range of 5 < U∗ < 130. Two synchronized fast-imaging cameras were used to reconstruct the motion of the
filaments in three dimensions, and a blend of linear and nonlinear time-series analysis techniques was used to
analyze the observed dynamics. Long filaments show a rich dynamics as the wind speed is gradually increased,
ranging from small amplitude vibration to large amplitude limit-cycle oscillation and to a more complex chaotic
motion. However, short filaments only exhibit a small amplitude vibration-like motion throughout the range of
wind speeds tested. Turbulent buffeting is identified as the main source of excitation responsible for the observed
filaments dynamics. The results highlight the importance of the filament damping ratio, which is modulated by
the filament length, as a controlling parameter for the dynamics of flexible filaments in cross flow, in addition to
the flow velocity. The Scruton number for these tests correspond to 31 < Sc < 86.
Description
Keywords
Limit-cycle oscillation Turbulence buffeting Turbulence-induced vibration Filament Flexible fluid–structure interaction
Citation
Jorge Silva-Leon, Andrea Cioncolini, Antonio Filippone, Marco Domingos, Flow-induced motions of flexible filaments hanging in cross-flow, Experimental Thermal and Fluid Science, Volume 97, 2018, Pages 254-269, ISSN 0894-1777, https://doi.org/10.1016/j.expthermflusci.2018.04.023
Publisher
Elsevier