0
Research Papers: CFD and VIV

Investigation on the Stability of Parallel and Oblique Plates as Suppressors of Vortex-Induced Vibration of a Circular Cylinder

[+] Author and Article Information
Gustavo R. S. Assi

Assistant Professor
Department of Naval Architecture
and Ocean Engineering,
University of São Paulo,
São Paulo 05508-030, Brazil
e-mail: g.assi@usp.br

Guilherme S. Franco, Michaelli S. Vestri

Department of Naval Architecture
and Ocean Engineering,
University of São Paulo,
São Paulo 05508-030, Brazil

1Corresponding author.

Contributed by the Ocean, Offshore, and Arctic Engineering Division of ASME for publication in the JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING. Manuscript received September 26, 2013; final manuscript received May 23, 2014; published online June 19, 2014. Assoc. Editor: Antonio C. Fernandes.

J. Offshore Mech. Arct. Eng 136(3), 031802 (Jun 19, 2014) (9 pages) Paper No: OMAE-13-1090; doi: 10.1115/1.4027789 History: Received September 26, 2013; Revised May 23, 2014

Experiments have been carried out with models of free-to-rotate parallel and oblique plates fitted to a rigid section of circular cylinder to investigate the effect of plate length and oblique angle on the stability of this type of vortex-induced vibration (VIV) suppressor. Measurements of the dynamic response and trajectories of motion are presented for models with low mass and damping which are free to respond in the cross-flow and streamwise directions. It is shown that, depending on a combination of some geometric parameters, the devices might not be able to completely suppress VIV for the whole range of reduced velocities investigated. Plates with larger oblique angles turned to be less stable than parallel plates and induced high-amplitude vibrations for specific reduced velocities. Systems may present streamwise vibration due to strong flow separation and reattachment on the outer surface of plates with large oblique angles. Large angles may also increase drag. Experiments with a plain cylinder in the Reynolds number range from 3000 to 20,000 have been performed to serve as reference. Reduced velocity was varied between 2 and 13. Two-dimensional numerical simulation of static systems at Re = 10,000 revealed that complex and fully separated flow regimes exist for almost all investigated cases. There is a good chance that systems with such geometric characteristics will be unstable unless other structural parameters are positively verified.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

(a) First experiment: Free-to-rotate parallel plates. Fixed G/D = 0.4 and α = 0 deg, varying L/D = 0.5, 1.0, 1.5, and 2.0 from top to bottom. (b) Second experiment: Free-to-rotate oblique plates. Fixed G/D = 0.4 and L/D = 1.0, varying α = 0 deg, 10 deg, 20 deg, and 30 deg from top to bottom.

Grahic Jump Location
Fig. 2

Experimental setup: cylinder with parallel plates mounted on the two-degrees of freedom rig in the test section of the NDF-USP water channel

Grahic Jump Location
Fig. 3

First experiment: cross-flow (y∧/D) and streamwise (x∧/D) amplitude of vibration versus reduced velocity for a plain cylinder compared to cylinders fitted with parallel plates of various lengths

Grahic Jump Location
Fig. 4

Second experiment: cross-flow (y∧/D) and streamwise (x∧/D) amplitude of vibration versus reduced velocity for a plain cylinder compared to cylinders fitted with oblique plates of various angles

Grahic Jump Location
Fig. 5

Reference experiment: trajectories of motion for a plain cylinder

Grahic Jump Location
Fig. 6

First experiment: trajectories of motion for a cylinder fitted with parallel plates of different lengths

Grahic Jump Location
Fig. 7

Second experiment: trajectories of motion for a cylinder fitted with oblique plates of different angles

Grahic Jump Location
Fig. 8

Reference simulation: wake of a plain cylinder

Grahic Jump Location
Fig. 9

Wake of a cylinder with oblique plates: fixed G/D = 0.4 and L/D = 1.0, varying α = 0 deg, 10 deg, 20 deg, and 30 deg from top to bottom

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In