Show simple item record

dc.contributor.advisorHeidi M. Nepf.en_US
dc.contributor.authorPalmer, Molly R., 1978-en_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Civil and Environmental Engineering.en_US
dc.date.accessioned2005-05-19T15:18:04Z
dc.date.available2005-05-19T15:18:04Z
dc.date.copyright2003en_US
dc.date.issued2003en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/16922
dc.descriptionThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.en_US
dc.descriptionIncludes bibliographical references (leaves 73-75).en_US
dc.descriptionThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.en_US
dc.description.abstractCapture of suspended particles by cylindrical collectors is an important mechanism in many aquatic processes, such as larval settlement, suspension feeding, and vegetative filtration. The collector Reynolds number (Rec), based on the collector diameter, typically ranges from 1-1000 in aquatic environments. No analytical solutions exist to describe capture efficiency in this range. Laboratory experiments are used to measure capture efficiency of a single cylinder as a function of Rec and particle ratio, R, which is the ratio of particle diameter to collector diameter. Rec is varied from 50 to 500 and three values of R are used: 0.03, 0.015, and 0.008. For smooth cylinders, capture increases with both Rec and R, but is more strongly dependent on R. This indicates that in aquatic systems, where flow velocity and suspended particle type and size are fixed, proportionally more capture will occur on the smallest collectors (those with largest R). An empirical equation is developed that predicts capture to single cylinders. Furthermore, published data for an experiment in which particles are collected by branched structures can be predicted by the empirical equation. This indicates that capture to individual cylindrical branches within a compound structure can be predicted by single-cylinder efficiencies. In addition, a model of a Spartina alterniflora wetland is presented which shows that the mechanism of particle capture can remove a significant portion of suspended particles. Finally, experiments in which roughness elements were added to the collectors showed that capture increased when compared to the smooth cases. A model is presented based on the added drag associated with the roughness elements that describes when roughness elements can enhance, and under certain circumstances, diminish capture.en_US
dc.description.statementofresponsibilityby Molly R. Palmer.en_US
dc.format.extent75 leavesen_US
dc.format.extent1249299 bytes
dc.format.extent1249048 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
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/1721.1/7582
dc.subjectCivil and Environmental Engineering.en_US
dc.titleObservations of a particle capture on a cylindrical collector : implications for particle accumulation and removal in aquatic systemsen_US
dc.typeThesisen_US
dc.description.degreeS.M.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Civil and Environmental Engineering.en_US
dc.identifier.oclc52872472en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record