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dc.contributor.advisorMichael S. Triantafyllou.en_US
dc.contributor.authorSteele, Stephanie Chinen_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Mechanical Engineering.en_US
dc.date.accessioned2013-03-28T18:13:15Z
dc.date.available2013-03-28T18:13:15Z
dc.date.copyright2012en_US
dc.date.issued2012en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/78192
dc.descriptionThesis (S.M. in Ocean Engineering)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (p. 59-60).en_US
dc.description.abstractWe explore several aspects of the phenomenon we call global vorticity shedding. Global vorticity shedding occurs when an object in viscous fluid suddenly vanishes, shedding the entire boundary layer vorticity into the wake at once. In our experiments we approximate the disappearance of a towed foil by rapidly retracting the foil in the span-wise direction. Global vorticity shedding is in distinct contrast with conventional shedding, in which vorticity is shed from a body from only a few separation points into the fluid. In this work, we show that for a square-tipped vanishing foil at an angle of attack, the globally shed boundary layer vorticity forms into primary vortices, which evolve and eventually amalgamate with secondary vortices to leave two lasting vortices in the wake. The secondary vortices are a result of three-dimensionality in the flow. For a streamlined-end foil, we achieve a simpler and less three-dimensional wake with no secondary vortices, arid only one lasting vortex dominating the wake. However, due to the initial vorticity distribution near the streamlined end of the foil, the initial circulation is reduced. We also show that the lasting vortices are capable of producing reasonably large forces on a body through simple potential flow estimations, aid that vortex formation times are small, with vortices fully formed nearly instantaneously in the flow. These features are promising for a force transducer using global vorticity shedding to impart large and fast maneuvering forces on an underwater vehicle.en_US
dc.description.statementofresponsibilityby Stephanie Chin Steele.en_US
dc.format.extent60 p.en_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.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.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectMechanical Engineering.en_US
dc.titleGlobal vorticity shedding for a vanishing foilen_US
dc.typeThesisen_US
dc.description.degreeS.M.in Ocean Engineeringen_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Mechanical Engineering.en_US
dc.identifier.oclc830376795en_US


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