Mathematical modeling of particle aggregation and vertical transport in aquatic environments using fractal and curvilinear approaches /
Due to recently enhanced understanding of particle aggregation in aquatic environments, we now have four possible approaches to modeling coagulation: the traditional Euclidean rectilinear, the Euclidean curvilinear, the fractal rectilinear, and the fractal curvilinear approaches. The primary purpos...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739363301&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Due to recently enhanced understanding of particle aggregation in aquatic environments, we now have four possible approaches to modeling coagulation: the traditional Euclidean rectilinear, the Euclidean curvilinear, the fractal rectilinear, and the fractal curvilinear approaches. The primary purpose of this research is to investigate which model among these best predicts observations of particle size distribution (PSD) and its evolution. In order to do this, two fractal coagulation kinetic models (rectilinear and curvilinear) were developed. The models are generalized models, meaning the Euclidean models are a subset of the fractal models, and have one spatial dimension incorporating sedimentation and vertical dispersion as well as coagulation. The second phase of this work was a comparison of the four models based on a series of observed PSD data from a 2-m settling column using estuarine sediment particles. Nonlinear parameter estimation was performed to estimate two free parameters for the fractal models (the fractal dimension, DF, and the collision efficiency factor, a), and one free parameter, a, for the Euclidean models. Compared with the observed PSD, the simulation showed that the fractal rectilinear model was best among the competing models, and that this model fit better for the larger size particles. The estimated DF was between 2.6 and 3.0. The Euclidean curvilinear model underestimated the collision rates even with an a of 1.0, and the resultant fitting was worse than the Euclidean rectilinear case, contrary to the general belief. The research demonstrated that the alphass were calculated to have multiple values, depending on the coagulation models assumed. This finding appears to be significant because a is currently used as a single value based on the conventional Euclidean rectilinear model. |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | xiii, 210 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 103-110. |