Flow physics behind the D-prism responses are further elucidated by the wake patterns based on a high-speed camera and the flow velocity spectra downstream of the prism.įlow-induced vibrations of an elastically supported circular cylinder have been extensively studied in the past decades, revealing various insightful fluid–structure interaction phenomena. The second transition response between low- and high-amplitude branches is found to be hysteretic and intermittent. Based on the response amplitudes and spectral traits, the D-prism exhibits the typical vortex-induced vibration (VIV) at α = 0°–30°, the first transition response at α = 45°–60°, the small-amplitude VIV response at α = 105°–135°, the second transition response at α = 150°–165°, the combined VIV-galloping response at α = 90°, and the pure galloping at α = 75° and 180°. The mass ratio of the prism is 11.35, and the structural damping ratio in still water is 0.0036. The Reynolds number range is 530–9620, and the reduced velocity range is 1–32, based on the projected prism width in the crossflow direction.
In this paper, we present a new experimental observation of flow-induced vibrations and associated spectral characteristics of a transversely oscillating D-section prism at an angle of attack α varying from 0° to 180°, where α = 0° and 180° represent the configuration with the upstream curved and flat part, respectively. Fluid–structure interactions of non-circular prisms are of significance from a scientific and practical viewpoint.
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