Projects per year
Abstract
While the flow-induced vibration (FIV) of a circular cylinder has been characterised in considerable detail, the FIV of elliptical cylinders has not received similar attention. This study investigates the dynamic response of elastically-mounted elliptical cylinders with various cross-sectional aspect ratios (or elliptical ratios) in a free stream. The elliptical ratio is defined by ϵ=b∕a, where a and b are the streamwise and cross-flow dimensions, respectively, of the cross section of a cylinder placed at zero incidence angle. The elliptical ratios tested were in the restricted range of 0.67⩽ϵ⩽1.50, which was designed to achieve some but not too large a geometric deviation from a circular cylinder. The fluid–structure system was modelled using a low-friction air-bearing rig in conjunction with a free-surface recirculating water channel facility. This experimental set-up yielded very low mass and damping ratios. The FIV response was characterised as a function of reduced flow velocity. The results showed that the ellipses exhibited different response regimes as ϵ varied. Surprisingly, for the lowest elliptical ratio ϵ=0.67, there existed two separated lock-in regimes. However, for ϵ⩾0.80, lock-in occurred over only a single reduced velocity range that was characterised by different response regimes. As ϵ was increased above unity, lock-in tended to occur at considerably lower reduced velocities than for the circular cylinder case. Moreover, the peak vibration amplitude increased with the elliptical ratio. This means that the body vibration is enhanced, rather than attenuated, as the afterbody is reduced for an ellipse.
Original language | English |
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Pages (from-to) | 123-131 |
Number of pages | 9 |
Journal | Journal of Fluids and Structures |
Volume | 89 |
DOIs | |
Publication status | Published - Aug 2019 |
Keywords
- Elliptical cylinder
- Flow-induced vibration
- Fluid–structure interaction
Projects
- 1 Finished
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Wake Transitions and Fluid-Structure Interactions of Rotating Bluff Bodies
Hourigan, K., Lo Jacono, D., Sheridan, J., Thompson, M. & Leweke, T.
Australian Research Council (ARC), Monash University, CNRS - Centre National de la Recherche Scientifique (French National Centre for Scientific Research), Université Paul Sabatier (Paul Sabatier University)
1/01/15 → 6/11/18
Project: Research