Synchronization of three-dimensional cylinder wake to forced oscillation
ORAL
Abstract
Identification of synchronization between fluid and structural dynamics is important for avoiding detrimental situations in engineering systems. In this study, we investigate the synchronization characteristics between different forced oscillation modes of a circular cylinder and its three-dimensional wake at Re = 300. We utilize the phase-reduction analysis, which reduces the high-dimensional physics of periodic flows to a single variable "phase." The cylinder is moved impulsively in streamwise, crossflow, and rotary directions to obtain the corresponding phase sensitivity functions. Since three-dimensional flows are not perfectly periodic unlike two-dimensional flows, the response of the flow is ensemble averaged to process the three-dimensional nature of the wake. For any given periodic motion of the cylinder, the synchronizability is evaluated and the synchronization condition for the forcing frequency and amplitude is determined by computing phase-coupling functions. Effects of the three-dimensionality of flows on phase sensitivity functions are analyzed, revealing that three-dimensional structures contribute to reduced synchronizability of the flow compared to two-dimensional flows.
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Presenters
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Youngjae Kim
University of California, Los Angeles
Authors
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Youngjae Kim
University of California, Los Angeles
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Vedasri Godavarthi
University of California, Los Angeles
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Victoria Rolandi
University of California Los Angeles, University of California, Los Angeles
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Kunihiko Taira
UCLA, University of California, Los Angeles