

Type of Document Dissertation Author Vigilar, Gregorio G. Jr. URN etd-424817300974290 Title Determination of Optimal Stable Channel profiles Degree PhD Department Civil Engineering Advisory Committee
Advisor Name Title Kibler, David F. Liapis, Stergios I. Ragab, Saad A. Widdowson, Mark A. Diplas, Panayiotis Committee Chair Keywords
- momentum-diffusion
- mobile
- threshold
- stable
- optimal
Date of Defense 1997-01-28 Availability unrestricted Abstract A numerical model which determines the geometry of a threshold channel was
recently developed. Such a model is an important tool for designing unlined
irrigation canals and channelization schemes, and is useful when considering flow
regulation. However, its applicability is limited in that its continuously curving
boundary does not allow for sediment transport, which is an essential feature of
natural rivers and streams. That model has thus been modified to predict the
shape and stress distribution of an optimal stable channel; a channel with a
flat-bed region over which bedload transport occurs, and curving bank regions
composed of particles that are all in a state of incipient motion. It is the
combination of this channel geometry and the phenomenon of
momentum-diffusion, that allows the present model to simulate the "stable bank,
mobile bed" condition observed in rivers. The coupled equations of
momentum-diffusion and force-balance are solved over the bank region to
determine the shape of the channel banks (the bank solution). The width of the
channel1s flat-bed region is determined by solving the momentum-diffusion
equation over the flat-bed region (the bed solution), using conditions at the
junction of the flat-bed and bank regions that ensure matching of the bed and
bank solutions. The model was tested against available experimental and field
data, and was found to adequately predict the bank shape and significant
dimensions of stable channels. To make the model results more amenable to the
practic ing engineer, design equations and plots were developed. These can be
used as an alternative solution for stable channel design; relieving the practitioner
of the need to run the numerical program. The case of a stable channel that
transports both bedload and suspended sediment is briefly discussed. Governing
equations and a possible solution scheme for this type of channel are suggested;
laying the groundwork for the development of an appropriate numerical model.
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28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access Abstract.pdf 7.87 Kb 00:00:02 00:00:01 < 00:00:01 < 00:00:01 < 00:00:01 Appndxa.pdf 34.64 Kb 00:00:09 00:00:04 00:00:04 00:00:02 < 00:00:01 Appndxb.pdf 33.72 Kb 00:00:09 00:00:04 00:00:04 00:00:02 < 00:00:01 Appndxc.pdf 32.40 Kb 00:00:08 00:00:04 00:00:04 00:00:02 < 00:00:01 Appndxd.pdf 17.68 Kb 00:00:04 00:00:02 00:00:02 00:00:01 < 00:00:01 Chap1.pdf 9.84 Kb 00:00:02 00:00:01 00:00:01 < 00:00:01 < 00:00:01 Chap2.pdf 51.75 Kb 00:00:14 00:00:07 00:00:06 00:00:03 < 00:00:01 Chap3.pdf 48.11 Kb 00:00:13 00:00:06 00:00:06 00:00:03 < 00:00:01 Chap4.pdf 30.92 Kb 00:00:08 00:00:04 00:00:03 00:00:01 < 00:00:01 Chap5a.pdf 129.68 Kb 00:00:36 00:00:18 00:00:16 00:00:08 < 00:00:01 Chap5b.pdf 120.50 Kb 00:00:33 00:00:17 00:00:15 00:00:07 < 00:00:01 Chap5c.pdf 94.48 Kb 00:00:26 00:00:13 00:00:11 00:00:05 < 00:00:01 Chap6.pdf 39.70 Kb 00:00:11 00:00:05 00:00:04 00:00:02 < 00:00:01 Chap7.pdf 17.42 Kb 00:00:04 00:00:02 00:00:02 00:00:01 < 00:00:01 Etd.pdf 5.78 Kb 00:00:01 < 00:00:01 < 00:00:01 < 00:00:01 < 00:00:01 etd.pdf 5.78 Kb 00:00:01 < 00:00:01 < 00:00:01 < 00:00:01 < 00:00:01 Frontmtr.pdf 51.35 Kb 00:00:14 00:00:07 00:00:06 00:00:03 < 00:00:01 Refrnces.pdf 15.95 Kb 00:00:04 00:00:02 00:00:01 < 00:00:01 < 00:00:01 Vita.pdf 7.84 Kb 00:00:02 00:00:01 < 00:00:01 < 00:00:01 < 00:00:01
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