Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory
The paper presents a computational study of three-dimensional flow past a cylinder forced to oscillate in a uniform stream, following a figure-eight trajectory. Flow simulations were performed for Re = 400, for different cases, defined in terms of the oscillation mode (‘counter-clockwise’ or ‘clockw...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-03-01
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| Series: | Fluids |
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| Online Access: | https://www.mdpi.com/2311-5521/6/3/107 |
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| author | Sofia Peppa Lambros Kaiktsis Christos E. Frouzakis George S. Triantafyllou |
| author_facet | Sofia Peppa Lambros Kaiktsis Christos E. Frouzakis George S. Triantafyllou |
| author_sort | Sofia Peppa |
| collection | DOAJ |
| description | The paper presents a computational study of three-dimensional flow past a cylinder forced to oscillate in a uniform stream, following a figure-eight trajectory. Flow simulations were performed for Re = 400, for different cases, defined in terms of the oscillation mode (‘counter-clockwise’ or ‘clockwise’), for values of the ratio, F, of the transverse oscillation frequency to the Strouhal frequency close to 1.0. The results demonstrate that, for F ≤ 1.0, counter-clockwise cylinder motion is associated with positive power transfer from the flow to the cylinder, corresponding to excitation; for the clockwise motion, power transfer is negative at intermediate to high amplitudes, corresponding to damping. For the clockwise mode, in the range F = 0.9–1.1, a transition to two-dimensional vortex street is identified for transverse oscillation amplitude exceeding a critical value. This results from the induced suction of vortices, which moves vortex formation and shedding closer to the cylinder surface, thus resulting in a narrower wake, characterized by an effective lower Reynolds number. Both oscillation modes are characterized by higher harmonics in the lift force spectrum, with the third harmonic being very pronounced, while even harmonics are present for the case of clockwise mode, resulting from a wake transition to a “S + P” mode. |
| first_indexed | 2024-03-09T05:26:57Z |
| format | Article |
| id | doaj.art-18c29277f2e94083950dc6715a828ea8 |
| institution | Directory Open Access Journal |
| issn | 2311-5521 |
| language | English |
| last_indexed | 2024-03-09T05:26:57Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj.art-18c29277f2e94083950dc6715a828ea82023-12-03T12:35:56ZengMDPI AGFluids2311-55212021-03-016310710.3390/fluids6030107Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight TrajectorySofia Peppa0Lambros Kaiktsis1Christos E. Frouzakis2George S. Triantafyllou3Department of Naval Architecture, University of West Attica, 12243 Athens, GreeceDepartment of Naval Architecture and Marine Engineering, National Technical University of Athens, 15780 Athens, GreeceAerothermochemistry and Combustion Systems Laboratory, ETH Zurich, 8092 Zurich, SwitzerlandDepartment of Naval Architecture and Marine Engineering, National Technical University of Athens, 15780 Athens, GreeceThe paper presents a computational study of three-dimensional flow past a cylinder forced to oscillate in a uniform stream, following a figure-eight trajectory. Flow simulations were performed for Re = 400, for different cases, defined in terms of the oscillation mode (‘counter-clockwise’ or ‘clockwise’), for values of the ratio, F, of the transverse oscillation frequency to the Strouhal frequency close to 1.0. The results demonstrate that, for F ≤ 1.0, counter-clockwise cylinder motion is associated with positive power transfer from the flow to the cylinder, corresponding to excitation; for the clockwise motion, power transfer is negative at intermediate to high amplitudes, corresponding to damping. For the clockwise mode, in the range F = 0.9–1.1, a transition to two-dimensional vortex street is identified for transverse oscillation amplitude exceeding a critical value. This results from the induced suction of vortices, which moves vortex formation and shedding closer to the cylinder surface, thus resulting in a narrower wake, characterized by an effective lower Reynolds number. Both oscillation modes are characterized by higher harmonics in the lift force spectrum, with the third harmonic being very pronounced, while even harmonics are present for the case of clockwise mode, resulting from a wake transition to a “S + P” mode.https://www.mdpi.com/2311-5521/6/3/107vortex-induced vibrationsoscillating cylinderfigure-eight motionspectral element method |
| spellingShingle | Sofia Peppa Lambros Kaiktsis Christos E. Frouzakis George S. Triantafyllou Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory Fluids vortex-induced vibrations oscillating cylinder figure-eight motion spectral element method |
| title | Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory |
| title_full | Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory |
| title_fullStr | Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory |
| title_full_unstemmed | Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory |
| title_short | Computational Study of Three-Dimensional Flow Past an Oscillating Cylinder Following a Figure Eight Trajectory |
| title_sort | computational study of three dimensional flow past an oscillating cylinder following a figure eight trajectory |
| topic | vortex-induced vibrations oscillating cylinder figure-eight motion spectral element method |
| url | https://www.mdpi.com/2311-5521/6/3/107 |
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