Vortex Induced Vibrations of cylinders : experiments in reducing drag force and amplitude of motion

Reducing the deleterious effect of Vortex Induced Vibrations (VIV) in marine risers is an important task for ocean engineers; and many competing factors exist in the design of VIV suppression devices. This thesis explores the experimental minimization of the drag force and the disruption of vortex formation by utilizing VIV suppression devices. Two series of tests are conducted-both utilizing separate testing designs. The first tests are the flexible cylinder experiments, detailed in Chapter 2, which determine the drag force and vibration amplitude of numerous, original testing configurations. The second series of tests are the rigid cylinder, PIV experiments, detailed in Chapter 3. These tests measure both the drag force on the cylinder and the oscillating component of the lift force, the latter of which is a good indication of vortex formation. The Chapter 3 tests also image the test section wake-providing helpful insight into the physical process of vortex formation. In brief, this thesis presents a detailed description and results of the two series of original VIV suppression tests. Many original configurations are tested, and the results are contained herein.

Department dc:contributor.department

Joint Program in Ocean Engineering/Applied Ocean Physics and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Farrell, David Emmanuel

Advisor dc:contributor.advisor

• Michael S. Triantafyllou and Franz S. Hover.

• Joint Program in Ocean Engineering/Applied Ocean Physics and Engineering.
• Mechanical Engineering.
• Woods Hole Oceanographic Institution.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/39894

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/39894